Tesis sobre el tema "Enzymatic sensor"

Na constante busca de novas estratégias para melhorar a atividade catalítica, foi que a começos do século passado, a síntese de nanopartículas de formato controlado, tornou-se em um dos acontecimentos que revolucionaram a abordagem catalítica da Química, criando assim a linha da nanociência, onde com a síntese de nanopartículas de formato ao nível nano, é possível controlar as propriedades catalíticas dos materiais a nível macroscópico. O presente trabalho apresenta, a síntese de nanopartículas de óxido cuproso (NPs-Cu2O) com faces cristalográficas controladas. Foi possível sintetizar estruturas cúbicas, esféricas, e octaédricas, sendo os cubos e octaedros os que possuem faces cristalográficas de tipo (100) e (111), respectivamente. Entretanto, as esferas possuem uma mistura entre ambas das faces. As propriedades catalíticas das NPs-Cu2O foram testadas eletroquimicamente mediante uma reação modelo de detecção de glicose. As NPs-Cu2O, foram sintetizadas em médio básico com cloreto de cobre (CuC12) como percursor, posteriormente com concentrações diferentes de cloridrato de hidroxilamina (NH2OHoHCI) foram obtidas NPs-Cu2O com estrutura cúbica, octaédrica e esférica. Posteriormente, foram imobilizadas numa superfície de eletrodo de carbono vítreo, mediante a técnica de casting. A oxidação catalítica da glicose, permitiu observar que o desempenho da estrutura cúbica fossesuperior, com uma sensibilidade de 442 ± 7 µA mM-1 cm-2, enquanto as estruturas esféricas e octaédricas foram de 165 ± 3 µA mM-1 cm-2 e 38 ± 1 µA mM-1 cm-2, respectivamente. Seguido as NPs-Cu2O, foram testadas na presença de Ácido Ascórbico (AA) e Ácido Úrico (UA), foi observado que os cubos possuem uma seletividade única, comparada com as outras estruturas. Dito comportamento foi estudado com Analise computacional (DFT), onde foi possível de observar que a distribuição entre átomos de Cobre e Oxigênio, determina a seletividade do material. Numa segunda etapa, para entender a importância da conservação estrutural e integridade morfológica, foram testadas as NPs-Cu2O, aos diferentes dias após de ser sintetizadas, observando claramente uma relação entre estrutura e atividade catalítico. Foi observado que nas estruturas cúbicas o deterioro foi maior em comparação com as outras estruturas, isto acompanhado mediante DFT, foi determinado que estrutura cúbica apresenta uma maior interação com o oxigênio, provocando assim, que a rápida transformação de Cu(I) para Cu(II), como CuO. Por último as NPs-Cu2O, foram testadas por espectroscopia de fotoelétrons excitados por raios X (XPS), este analise ajudou a compreender que o desempenho catalítico, não estava relacionado com a formação de Cu (III). Estes resultados foram apoiados pelos resultados obtidos pela espectroscopia de infravermelho in situ (FTIR), já que nessa análise foi possível de observar como o estabilizante (SDS), foi determinante em cada estrutura.
In the constant search for new strategies by advance of catalytic activities, was that at the beginning of the last century the synthesis of nanoparticles in a controlled format, became one of the events that revolutionized the catalytic approach of Chemistry, thus creating a line of nanoscience, where with the synthesis of nanoparticles of format at the nano level, it is possible to control catalytic properties of materiais at the macroscopic level. Consequently, the present work the synthesis of cuprous oxide nanoparticles (Cu2O-NPs), with crystallography faces welldefined. It was possible synthesize cubic, spherical and octahedral structure, the cubes and octahedrons being those having crystallographic faces of type (100) and (111), respectively. Meanwhile, the spheres have a mixture between both faces. The catalytic properties of Cu2O-NPs were electrochemically tested by a model glucose detection reaction. The Cu2O-NPs were synthetized in basic solution with cooper chlorate (CuCl2) like precursor, after with different concentration of hydroxylamine hydrochloride (NH2OH· HCl) were obtain cubic, spheres and octahedral structure. Posteriorly, were immobilized in a glassy carbon surface, through the technique of casting. The catalyst oxidation of glucose allowed observe that the performance of cubic structure was superior, with a sensibility of 442 ± 7 µA mM-1 cm-2, while the spheres and octahedral structure were 165 ± 3 µA mM-1 cm-2 e 38 ± 1 µA mM-1 cm-2, respectively. Following the Cu2O-NPs, they were tested in the presence of Ascorbic Acid (AA) and Uric Acid (UA), it was observed that the cubes have a unique selectivity compared to the other Cu2O-NPs structure. This behavior was studies with com putational analysis (DFT), where it was possible to observed that the distribution between copper and oxygen atoms determines the selectivity of material. In a second step, to understand the importance of structure conservation and morphological integrity, Cu2O-NPs were tested at different days after being synthesized, noting clearly a relation between structure and catalytic activity. It was observed that cubic structure the deterioration was greater in comparation with the other structures, this being accompanied by DFT, it was determinate that cubic structure show a greater interaction with the oxygen, thus provoking that rapid transformation of Cu (I) to Cu(II), like CuO. Finally, the Cu2O-NPs were tested by x-ray excited photoelectron spectroscopy (XPS), this analysis helped to understand the catalytic activity was not related to Cu (III) formation. These results were supported by those obtained by in situ (FTIR), since in this analysis it was possible to observe how the stabilizer (SDS) was determinant in each structure.

This thesis presents the achievements and scientific work conducted using a previously designed and fabricated 64 x 64-pixel ion camera with the use of a 0.35 μm CMOS technology. We used an array of Ion Sensitive Field Effect Transistors (ISFETs) to monitor and measure chemical and biochemical reactions in real time. The area of our observation was a 4.2 x 4.3 mm silicon chip while the actual ISFET array covered an area of 715.8 x 715.8 μm consisting of 4096 ISFET pixels in total with a 1 μm separation space among them. The ion sensitive layer, the locus where all reactions took place was a silicon nitride layer, the final top layer of the austriamicrosystems 0.35 μm CMOS technology used. Our final measurements presented an average sensitivity of 30 mV/pH. With the addition of extra layers we were able to monitor a 65 mV voltage difference during our experiments with glucose and hexokinase, whereas a difference of 85 mV was detected for a similar glucose reaction mentioned in literature, and a 55 mV voltage difference while performing photosynthesis experiments with a biofilm made from cyanobacteria, whereas a voltage difference of 33.7 mV was detected as presented in literature for a similar cyanobacterial species using voltamemtric methods for detection. To monitor our experiments PXIe-6358 measurement cards were used and measurements were controlled by LabVIEW software. The chip was packaged and encapsulated using a PGA-100 chip carrier and a two-component commercial epoxy. Printed circuit board (PCB) has also been previously designed to provide interface between the chip and the measurement cards.

Le domaine de la bioélectronique, qui couple l'électronique et la biologie, présente un fort potentiel pour le développement de nouveaux outils biomédicaux. Les dispositifs à base d’électronique organique sont particulièrement prometteurs; l'utilisation de ces matériaux organiques confère une interface idéale entre les mondes biologique et électronique en raison de leur biocompatibilité et de leur possible grande flexibilité. Le transistor électrochimique organique (OECT) représente un dispositif prometteur dans ce domaine. Des OECT ont par exemple été intégrés dans des systèmes permettant de détecter localement l’activité ionique/biomoléculaire, de mesurer l'activité d'une cellule unique, mais aussi d’effectuer la caractérisation de tissus et le suivi du fonctionnement d’organes entiers. L'OECT est un dispositif extrêmement polyvalent qui apparaît comme un outil thérapeutique et de diagnostic de première importance. L'utilisation de matériaux organiques tels que les polymères conducteurs, rend l‘OECT adaptable pour une large gamme d'applications. Un exemple représentatif est le capteur de glucose. L'OECT, en raison de ses propriétés d'amplification, peut augmenter ces courants de plusieurs ordres de grandeurs. Utilisé comme capteur de glucose, il montre une forte sensibilité et des limites de détection des concentrations de l’ordre du nanomolar. Cependant, en dehors d’une meilleure précision de mesure, la stabilité est nécessaire pour les applications à long terme. Par exemple, ces capteurs se doivent d'enregistrer en continu les variations de glycémie chez des personnes pendant plusieurs jours et sans défaillance. Le glucose est la source d'énergie principale du cerveau. Ainsi, l'enregistrement de la modulation des niveaux de glucose avant et/ou pendant la crise d'épilepsie peut donner beaucoup d'informations dans la compréhension de cette maladie. Pour des applications à long termes, une liaison covalente de la biomolécule est préférable.La biofonctionnalisation des polymères conducteurs, qui sont utilisés comme matières actives dans les OECTs, est une étape obligatoire qui mettra en évidence les propriétés de l’OECT telles que la biocompatibilité, la stabilité, et la fonctionnalité. Dans ce travail, des méthodes de biofonctionnalisation du poly (3,4-éthylènedioxythiophène) dopé avec des anions de tosylate (PEDOT: TOS) ou dopé avec du poly (styrène sulfonate) (PEDOT: PSS) ont été développéeset ont conduitsent à des améliorations telles que la biocompatibilité accrue avec les cellules et à une stabilité accrue pour les applications de détection. En outre, nous avons étudié l'utilisation de liquides ioniques en combinaison avec des polymères réticulables comme alternatives aux électrolytes conventionnelles. Ces gels ioniques électrolytes ont amélioré la stabilité des enregistrements électrophysiologiques. Enfin, des mesures in vitro de l'activité métabolique de la cellule ont été effectuées. Le suivi de l'absorption du glucose et de la conversion en lactate fournit des informations sur la santé des cellules et comment ses activités métaboliques sont affectées par la présence de composés toxiques et d’agents pathogènes
The rising field of bioelectronics, which couples the realms of electronics and biology, holds huge potential for the development of novel biomedical devices for therapeutics and diagnostics. Organic electronic devices are particularly promising; the use of robust organic electronic materials provides an ideal bio-interface due to their reported biocompatibility, and mechanical matching between the sensor element and the biological environment, are amongst the advantages unique to this class of materials. One promising device emerging from this field is the organic electrochemical transistor (OECT). The OECT combines properties and characteristics that can be tuned for a wide spectrum of biological applications. These applications have allowed the development of OECTs to sense local ionic/biomolecular and single cell activity, as well as characterization of tissue and even monitoring of function of whole organs. The OECT is an extremely versatile device that emerges as an important player for therapeutics and diagnostics.The use of organic materials, such as conducting polymers, makes the OECT tunable for a wide range of applications. For example, OECTs have been used for sensing applications. A representative example is the glucose sensor. The OECT has been used as glucose sensor and has shown high sensitivities and low limit of detection for concentrations at the nanomolar range. However, apart from high sensitivities, stability and reproducibility are common necessities for long term applications. For example, it is of equal importance for these sensors to continuously record variations of glucose for diabetic patients, since multiple measurements per day without failure are necessary. Additionally, stability is necessary for implantable sensors. For brain cells such as neurons, glucose is the main energy source. Thus recording modulations of glucose levels before or during an epileptic crisis will enhance our understanding of this disease. Long-term stabilities for these sensors can be achieved through biofunctionalization, which is a method to attach a biomolecule to a device. For long term applications a covalent binding of the biomolecule is preferred. Biofunctionalization of conducting polymers, which are used as active materials in OECTs, is a mandatory step that can enhance OECT properties such as biocompatibility, stability, and functionality. In this work, different biofunctionalization methods of poly(3,4-ethylenedioxythiophene) doped with tosylate anions (PEDOT:TOS) or doped with poly(styrene sulfonate) (PEDOT:PSS) have been explored. The biofunctionalization methods have led to improvements for different applications such as better interfaces with living cells, and better stability for enzymatic sensors. Additionally, we have employed the use of ionic liquids in combination with cross-linkable polymers as alternative solid state electrolytes. These electrolytes are improving the stability of recordings in electrophysiology. Finally, in vitro measurements of metabolic activities in cells have been explored. The monitoring of glucose uptake and its conversion to lactate is a sensitive indicator of the viability of these cells. Furthermore, in the presence of toxic compounds and pathogens, the nature or kinetics of these metabolic activities is getting affected. Therefore, OECTs used for glucose and lactate sensing can at the same time be used for Immunosensing

Molecular magnetic resonance imaging (MRI) methods have the potential to provide detailed information regarding cellular and molecular processes at small scales within the human body. Nuclear signals from chemical samples can be probed using specialised MRI techniques, to highlight molecular contrast from particular enzymes or metabolites. The aim of the work described in this thesis is to investigate both exogenous and endogenous contrast mechanisms using fluorine MRI and chemical exchange saturation transfer (CEST) respectively, in order to detect molecular changes in vitro. Initial theoretical work investigates the factors which affect fluorine MRI signals and provides a theoretical framework to determine the sensitivity of such experiments. A novel paramagnetic fluorine sensor to detect enzyme activity is then characterised using high field nuclear magnetic resonance (NMR), showing 60 to 70–fold increases in T1 relaxation values upon enzyme interaction. The effects on the fluorine lineshape from varying sample temperature and solvent were investigated. The possibility of imaging is demonstrated, but further investigations using the theoretical framework found pre–clinical implementation of the sensor is limited by the achievable experimental sensitivity. Efforts then focussed on CEST molecular methods, which are not limited by sensitivity. A protocol is developed to target amide protons in an in vitro cancer cell model, with parameters optimised following simulation of the expected contrast. Analysis of CEST results were aided through use of a support vector machine (SVM) to distinguish group differences between cancer cells and control samples. A linear classifier was found to be suitable to discriminate between samples.

Depuis 4 décennies, un modèle intermédiaire entre les traditionnelles approches in vivo et in vitro émerge : les Systèmes MicroPhysiologiques (SMP). Ils sont construits pour recréer différents niveaux de physiologie humaine, du simple organe à leurs interactions. Ils améliorent l’environnement de culture grâce à des microstructures accueillant des modèles d’architecture 3D et multicellulaire, et intègrent des microcapteurs monitorant l’activité cellulaire et leur environnement.Ce nouvel outil d’investigation est d’intérêt pour la recherche fondamentale sur les maladies comme le diabète. Dans le cas de cette maladie incurable, la régulation du glucose sanguin, résultant d’interactions complexes entre les îlots pancréatiques, le foie, les adipocytes et les muscles, est altérée. Un Multi-Organe-sur-Puce (MOsP) est un SMP pouvant reproduire ces interactions, et représente donc un modèle pertinent pour la recherche sur le diabète. En effet, la régulation inter-organe n’est pas entièrement reproduite par les modèles in vitro usuels, et requiert de multiples capteurs, ce qui est éthiquement et techniquement impossible in vivo. Dans le contexte du diabète, il n’existe aucun MOsPs reproduisant l’action des îlots sur les muscles, malgré l’importance des muscles squelettiques dans la régulation glycémique.Cette thèse propose une méthodologie pour construire un MOsP étudiant les interactions d’îlot à muscle dans la régulation glycémique. Les 3 objectifs du MOsP étaient : atteindre des concentrations physiologiques d’insuline grâce à des îlots sécrétant en réponse à une élévation physiologique de glucose, induisant une prise de glucose mesurable par les muscles, et monitorer l’expérience en direct. Pour cela, les investigations ont été menées avec une approche interdisciplinaire, utilisant et confrontant des résultats venant d’expériences biologiques in vitro et de simulations modélisant la biologie et la physique.Ce manuscrit détaille les étapes de la méthodologie, et délivre différents designs pour progressivement construire un MOsP comprenant: une puce microfluidique contenant les cellules et un capteur de glucose connecté directement au flux. Les principales découvertes ont été :- Un milieu et procédure de co-culture entre îlots primaires et LHCN-M2 myotubes ont été démontrés.- Un substrat de culture commun de type MicroElectrodes Array a été trouvé.- Des îlots ont été cultivés en puce microfluidique, et ont présenté une sécrétion d’insuline en réponse au glucose durant des expériences en fluidique. Des myotubes ont pu se différentier en puce, et ont présenté une prise de glucose basale (insuline indépendant).- Une stratégie in vitro-in silico pour dimensionner le MOsP a été développée et implémentée. Un modèle in silico simplifié d’îlot a été développé pour rapidement explorer 2 designs de puce. Des expériences in vitro correspondantes, de sécrétion d’insuline, ont été menées et confrontées aux expériences in silico. Les résultats ont soulevé l’hypothèse que les îlots n’avaient pas une fonctionnalité optimale dans nos petits volumes de culture. La même constatation a été faite concernant les myotubes, où la prise de glucose insuline dépendante a été démontrée en macro volumes, mais en micro volumes, la réponse observée (uniquement à concentration physiologique d’insuline) doit être reproduite avec des expériences plus robustes pour démontrer leur présence.- Un capteur de glucose compatible avec le système microfluidique a été caractérisé à l’aide d’expériences in vitro et in silico.- Un multi-potentiostat a été développé dans la perspective de futures mesures électrochimiques multiples et intégrées.Les bases et perspectives présentées ici permettront d’achever le MOsP îlot-muscle par de futurs travaux. La méthodologie peut aussi être réutilisée pour l’ajout de nouveaux organes (foie, adipocytes) complétant le MOsP, qui permettra de mieux comprendre les dérégulations intervenant dans le diabète de type 2
Over the past 4 decades, an intermediate model between the traditional in vivo and in vitro approaches has emerged: the MicroPhysiological Systems (MPS). MPS are designed to recapitulate different levels of human physiology, from the single organ to organs crosstalk. They upgrade the culture environment by patterning microstructures hosting 3D and multicellular architecture models and integrate microsensors monitoring cell activity and environment.This new investigation tool is of interest in fundamental research on diseases such as diabetes. In this incurable disease, blood glucose regulation, resulting from a complex organs interplay between the pancreatic islets, the liver, the adipocytes and the muscles, is impaired. A Multi-Organ-on-a-Chip (MOoC) is a MPS that can recapitulate these organs crosstalk and represents a relevant model for diabetes research. Indeed, inter-organ regulations are not recapitulated by usual in vitro models, and deciphering these interactions requires multiple sensors, which is not ethically and technically possible in vivo. In the context of diabetes, MOoCs reproducing the islets to skeletal muscles communication do not exist so far, despite the importance of the skeletal muscles impact on blood glucose, under islets action.In this thesis, we propose a methodology to design a MOoC deciphering islets to muscles interactions in blood glucose regulation. The MOoC objectives were to: (i) attain physiological insulin concentration secreted by islets in response to physiological glucose elevation, (ii) that induces a measurable glucose uptake by the muscle cells, (iii) monitor online relevant parameters. To that end, the investigations were conducted with an interdisciplinary approach, using and confronting results from both in vitro biological experiments and in silico modelling of biology and physics.This manuscript details the methodology steps, delivering different designs for progressive validation toward a complete MOoC that comprises a microfluidic chip with cells and an online glucose sensor. During the MOoC construction, our main findings were the following:- A co-culture medium and procedure for primary islets and LHCN-M2 myotubes were demonstrated.- A common MicroElectrodes Array-based substrate was found suited for co-culture in a single microfluidic chip.- Islets were cultured in microfluidic chips, and presented an insulin secretory response to glucose during fluidic experiments. Myotubes were successfully differentiated in microfluidic chips, and presented a measurable basal (insulin-independent) glucose uptake.- An in silico and in vitro informed MOoC scaling strategy was developed and implemented. A simplified in silico islet model was developed to rapidly explore chip designs. Corresponding in vitro insulin secretion experiments were conducted and confronted to the in silico experiments. Results raised the hypothesis that islets function was sub optimal when cultured in our low volume. Similar observation was made concerning myotubes scaling, where insulin-dependent glucose uptake was demonstrated in macro volumes experiments, but in micro volumes, the observed insulin response (only at physiological insulin concentration) has to be further repeated with improved experiments to explicitly demonstrate its presence.- A glucose biosensor compatible with microfluidic was characterized under different injection protocols, using in vitro and in silico experiments.- A multi-potentiostat was developed in the perspective of multiple and integrated electrochemical sensing in the MOoC.From the grounds and perspectives presented in this thesis, future work can be conducted to further complete this islet-muscle MOoC. The methodology can be re-used and extended in the perspective of adding new organs (liver, adipocytes) in this MOoC in order to better address the interorgan crosstalk deregulations in type 2 diabetes pathophysiology

Les tests sur le lieu de soins sont très prometteurs car ils permettent d'effectuer des mesures en temps réel et en continu à un prix abordable et s'adressent à un large éventail de personnes. Cependant, le défi que représente la surveillance continue pour gérer la santé de manière proactive tout en réduisant les dépenses de santé est considérable. Il s'agit principalement de garantir la fiabilité des éléments de reconnaissance et la viabilité à long terme des sources d'énergie, en particulier des batteries. Cette étude a établi un capteur de lactate non enzymatique pour les tests sur le lieu de soins, en utilisant une approche holistique qui comprend la modification de la morphologie de l'électrode, l'électrodéposition de matériaux conducteurs et de catalyseurs à l'échelle nanométrique, l'intégration d'un liquide ionique pour la sélectivité, l'optimisation de la technologie d'alimentation sans fil et l'incorporation de systèmes de gestion de l'énergie dans des dispositifs de détection électrochimique conçus par l'utilisateur lui-même. Les principaux résultats comprennent la sélectivité des catalyseurs non enzymatiques pour la détection et la proposition d'un dispositif de mesure personnalisé alimenté sans fil. Plus précisément, la modification de la géométrie du noyau du transformateur en ferrite a amélioré la puissance de sortie maximale du transducteur magnétoélectrique, qui a atteint 1,63 mW. Le circuit de gestion de l'énergie proposé fournit du courant continu avec un rendement élevé (0,74 mW) et permet une charge plus rapide pour la transmission d'énergie sans fil afin de soutenir nos dispositifs électrochimiques. Les dispositifs d'analyse électrochimique tels qu'ils ont été fabriqués ont démontré des capacités de mesure précises. L'utilisation de l'électrode poreuse imprimée a permis d'améliorer la reproductivité, la conductivité et la surface. L'électrodéposition de graphène et de nanoparticules de Ni(OH)₂, dont la taille et l'état chimique ont été soigneusement réglés, a augmenté la sensibilité du capteur. La plage de détection étendue des capteurs d'acide lactique optimisés s'avère avantageuse pour la détection du lactate, ce qui présente des avantages significatifs pour le diagnostic de diverses maladies. Un liquide ionique synthétisé sur mesure a facilité la détection sélective de l'acide lactique, en bloquant les molécules d'interférence et en permettant une détection "en une étape" avec une large gamme (1 mM à 60 mM) et une sensibilité élevée (1,374 μA/mM). En outre, la performance électrochimique du capteur non enzymatique avec liquide ionique a été étudiée en corrélant le coefficient de diffusion avec la Stokes-Einstein relationship. En conclusion, cette recherche offre des perspectives précieuses sur des systèmes de tests de soins au point d'intervention entièrement intégrés avec des applications pratiques, notamment les capteurs de lactate non enzymatiques avec des liquides ioniques et les transducteurs magnétoélectriques pour le transfert d'énergie sans fil. L'effort continu visant à améliorer les dispositifs de tests de soins au point d'intervention souligne l'importance de la recherche et de l'innovation soutenues pour faire progresser les soins aux patients et la gestion des maladies dans divers domaines, y compris la médecine clinique, la gestion du sport et la recherche sur le cancer
Point-of-care testing (POCT) holds great promise for providing real-time and continuous measurements at an affordable price, catering to a broad range of individuals. However, the challenge of continuous monitoring to proactively manage health while reducing healthcare expenses is substantial. These challenges primarily revolve around ensuring the reliability of recognition elements and the long-term sustainability of power sources, particularly batteries. This study established a non-enzymatic lactate sensor for point-of-care testing, employing a holistic approach that encompasses the modification of electrode morphology, electrodeposition of nanoscale conductive materials and catalysts, integration of ionic liquid for selectivity, optimization of wireless power supply technology, and the incorporation of power management systems into self-designed electrochemical detection devices. Key findings include conferring selectivity on non-enzymatic catalysts for detection and proposing a custom wirelessly supplied measurement device. Specifically, modifying the ferrite transformer core geometry improved the magnetoelectric transducer's maximum output power, reaching 1.63 mW. The proposed power management circuit supplied DC with high efficiency (0.74 mW) and enabled faster charging for wireless power transmission to support our electrochemical devices. The as-fabricated electrochemical analysis devices demonstrated precise measurement capabilities.Using the porous screening printed electrode showed increased reproductivity, conductivity, and surface area. The electrodeposition of graphene and Ni(OH)₂ nanoparticles, carefully regulated in size and chemical state, elevated the sensor's sensitivity. The extensive detection range of the optimized lactic acid sensors proves advantageous for detecting lactate, offering significant benefits in various disease diagnoses. A custom-synthesized ionic liquid facilitated selective detection of lactic acid, blocking interference molecules and enabling "1-step" detection with a wide range (1 mM to 60 mM) and high sensitivity (1.374 μA/mM). Additionally, the electrochemical performance of the non-enzymatic sensor with ionic liquid was investigated by correlating the diffusion coefficient with the Stokes-Einstein relationship. In conclusion, this research provides valuable insights into fully integrated POCT systems with practical applications, including the non-enzymatic lactate sensors with ionic liquids and magnetoelectric transducers for wireless power transfer. The ongoing effort to enhance POCT devices underscores the importance of sustained research and innovation in advancing patient care and disease management across various fields, including clinical medicine, sports management, and cancer research

[EN] Persimmon (Diospyros kaki L.) 'Rojo Brillante' is an astringent variety characterised by good growing conditions, excellent colour, size, sensory characteristics and good nutritional properties. In the last decade, its production has grown substantially in Spain given the application of high levels of CO2 to remove astringency while firmness is preserved. This technology has also increased its potential as a fresh-cut commodity. However, physical damage during processing result in degradation of the colour and firmness of the product and a higher susceptibility to microbial spoilage that significantly reduces the fruit's shelf life. The objective of the present thesis was to develop optimum procedures for processing and marketing 'Rojo Brillante' persimmon into a fresh-cut product with the maximum shelf life and best physicochemical, nutritional, sensory and microbiological quality. Firstly, the objective was to evaluate the effect of the maturity stage (MS) at harvest, storage time at 15 ºC before processing, and the application of different antioxidant treatments on enzymatic browning, sensory and nutritional quality of fresh-cut 'Rojo Brillante' persimmon during storage at 5 ºC. Concentrations of 10 g L-1 ascorbic acid (AA) or 10 g L-1 citric acid (CA) controlled tissue browning and maintained the visual quality of fresh-cut persimmon above the limit of marketability for 6-8 storage days at 5 ºC, depending on the MS. However, these acidic solutions reduced fruit firmness as compared to control samples. Further studies showed that the combination of these antioxidants with 10 g L-1 CaCl2 maintained firmness of the persimmon slices within the same range as the control samples. In another work, the application of 1-methylcyclopropene (1-MCP) allowed to process fruits after 45 days of storage at 1 ºC with commercial firmness and the antioxidant solution (10 g L-1 CA + 10 g L-1 CaCl2) extended the limit of marketability up to 9 days of storage at 5 ºC. Different controlled atmosphere conditions in combination with AA or CA dips were also evaluated as a first step to select optimum O2 and CO2 concentrations for modified atmosphere packaging (MAP) of fresh-cut 'Rojo Brillante' persimmons. Overall, the combination of antioxidant dips and a controlled atmosphere composed of 5 kPa O2 (balance N2) was proved to be the most effective combination to control enzymatic browning. This atmosphere maintained the visual quality of persimmon slices within the limit of marketability during 7- 9 days at 5 ºC. On the contrary, high CO2 concentrations (10 or 20 kPa) induced darkening in some tissue areas, associated with a flesh disorder known as 'internal flesh browning'. Later studies confirmed the beneficial effect of an active MAP in 5 kPa O2 compared to passive MAP to improve the visual quality of fresh-cut 'Rojo Brillante' persimmon, showing a synergic effect with the antioxidant dip (10 g L-1 CA + 10 g L-1 CaCl2). Antioxidant edible coatings were prepared from whey protein isolate (WPI), soy protein isolate (SPI), hydroxylpropyl methylcellulose (HPMC) and apple pectin as the polymeric matrix. All edible coatings were amended with the antioxidant combination selected (10 g L-1 CA + 10 g L-1 CaCl2). All the edible coatings tested proved effective to control enzymatic browning of persimmon slices. However, the samples treated with the HPMC- and pectin- based coatings were scored with a better visual quality that the rest of the treatments. In general, free radical scavenging activity and total carotenoid content increased in late-season persimmons; whereas, processing (cutting and storage at 5 ºC), antioxidant dips, controlled atmosphere storage or edible coatings had no clear effect on nutritional quality (vitamin C, free radical scavenging activity, total phenolic content, and carotenoids) of fresh-cut persimmons.
[ES] El caqui persimmon (Diospyros kaki L.) 'Rojo Brillante' es un cultivar astringente que presenta unas propiedades organolépticas y nutricionales excelentes. En la última década, su cultivo en el área mediterránea de España se ha incrementado de manera exponencial con el desarrollo de la tecnología que permite eliminar la astringencia, manteniendo la firmeza del mismo. Esta nueva forma de presentación, aporta numerosas ventajas, entre la que se incluye la posibilidad de ser comercializado como fruta fresca cortada. Sin embargo, el éxito comercial del producto está limitado por el pardeamiento enzimático, la pérdida de firmeza y al crecimiento microbiano. En este contexto, el objetivo de la Tesis ha sido el desarrollo de caqui 'Rojo Brillante' fresco cortado mediante un enfoque que integra el estudio de las características del producto en el momento del procesado y de distintas tecnologías que mantengan la calidad físico-química, sensorial, nutricional y microbiológica del producto durante un periodo que permita su comercialización. En primer lugar, se evaluó el efecto del estado de madurez (MS) en el momento de recolección, el tiempo de almacenamiento a 15 ºC antes del procesado y la aplicación de diferentes antioxidantes en el pardeamiento enzimático y la calidad sensorial y nutricional del caqui 'Rojo Brillante' cortado y almacenado a 5 ºC. La aplicación de 10 g L-1 de ácido ascórbico (AA) ó 10 g L-1 ácido cítrico (CA) controló el pardeamiento enzimático y mantuvo la calidad visual del caqui por encima del límite de comercialización entre 6 y 8 días de almacenamiento a 5 ºC, dependiendo del MS. Sin embrago, la aplicación de estos antioxidantes redujo de manera significativa la firmeza del fruto respecto al control. La combinación de estos antioxidantes con 10 g L-1 de CaCl2 permitió mantener la firmeza en el mismo rango que las muestras control. En un trabajo posterior, la aplicación de 1-metilciclopropeno (1-MCP) permitió procesar caqui almacenado 45 días a 1 ºC con una buena firmeza comercial y el tratamiento antioxidante (10 g L-1 CA + 10 g L-1 CaCl2) consiguió alcanzar un límite de comercialización del producto de 9 días a 5 ºC. La evaluación de distintas atmósferas controladas en combinación con tratamientos antioxidantes (AA o CA), como paso previo al envasado en atmósfera modificada (MAP) del caqui, mostró como más efectiva en el control del pardeamiento enzimático la atmósfera compuesta por 5 kPa O2 (balance N2). Esta atmósfera mantuvo la calidad visual del caqui cortado dentro del límite de comercialización durante 7-9 días a 5 ºC. Por el contrario, la aplicación de altas concentraciones de CO2 (10 ó 20 kPa) dio lugar a un pardeamiento en ciertas zonas de la pulpa que se conoce como 'internal flesh browning'. Estudios posteriores confirmaron el efecto beneficioso del envasado de caqui cortado y tratado con solución antioxidante (CA-CaCl2) en una MAP activa de 5 kPa O2 en la calidad visual del fruto frente a la aplicación de una MAP pasiva. El desarrollo de recubrimientos comestibles con capacidad antioxidante se realizó mediante la incorporación de antioxidantes (10 g L-1 CA + 10 g L-1 CaCl2) a formulaciones a base de proteína de suero lácteo (WPI), proteína de soja (SPI), hidroxipropilmetilcelulosa (HPMC) y pectina. Todos los recubrimientos fueron efectivos controlando el pardeamiento enzimático del caqui cortado, siendo las muestras recubiertas con HPMC y pectina las mejor evaluadas visualmente. En general, el procesado, la aplicación de antioxidantes, el envasado en atmósferas controladas y los distintos recubrimientos comestibles estudiados, si bien no mostraron un efecto claro en los parámetros de calidad nutricional evaluados, no tuvieron un efecto negativo en los mismos. Por otra parte, los frutos cosechados a final de campaña tuvieron mayor actividad antioxidante y contenido en carotenoides.
[CAT] El caqui persimmon (Diospyros kaki L.) 'Rojo Brillante' és un cultiu astringent que presenta unes propietats organolèptiques i nutricionals excel¿lents. En la última dècada, el seu cultiu en l'àrea mediterrània d'Espanya s'ha incrementat de manera exponencial amb el desenvolupament de la tecnologia que permet eliminar l'astringència, mantenint la fermesa del mateix. Esta nova forma de presentació, aporta un gran nombre d'avantatges, entre els quals s'inclou la possibilitat de comercialitzar-lo com fruita fresca processada. No obstant, l'èxit comercial del producte està limitat per pardetjament enzimàtic, la pèrdua de fermesa i el creixement microbià. L'objectiu de la Tesis ha estat en el desenvolupament de caqui 'Rojo Brillante' tallat en fresc mitjançant un enfocament que integra l'estudi de les característiques del producte en el moment del processat i de diferents tecnologies en el manteniment de la qualitat físico-química, sensorial, nutricional i microbiològica del producte durant un període que permeta la seua comercialització. En primer lloc, es va avaluar l'efecte de l'estat de maduresa (MS) en el moment de recol¿lecció, el temps d'emmagatzemament a 15ºC abans del processat i l'aplicació de diferents tractaments antioxidants en el pardetjament enzimàtic i la qualitat sensorial i nutricional del caqui 'Rojo Brillante' tallat i emmagatzemat a 5 ºC. L'aplicació de 10 g L-1 d'àcid ascòrbic (AA) o 10 g L-1 d'àcid cítric (CA) va controlar el pardetjament enzimàtic i va mantenir la qualitat visual del caqui per damunt del límit de comercialització entre 6-8 dies d'emmagatzemament a 5 ºC, depenent del MS. No obstant, l'aplicació d'antioxidants va reduir de manera significativa la fermesa del fruit comparat amb el control. La combinació d'aquestos antioxidants amb 10 g L-1 de CaCl2 va permetre mantenir la fermesa en el mateix rang que les mostres control. En un treball posterior, l'aplicació de 1-metilciclopropeno (1-MCP) va permetre processar caqui emmagatzemat 45 dies a 1 ºC amb una bona fermesa comercial i a més, el tractament antioxidant (10 g L-1 CA + 10 g L-1 CaCl2) va aconseguir un límit de comercialització del producte tallat de 9 dies a 5 ºC. L'avaluació de diferents atmosferes controlades en combinació amb tractaments antioxidants (AA o CA), com a pas previ a l'envasament en atmosfera modificada (MAP) del caqui 'Rojo Brillante, va mostrar com a més efectiva en el control del pardetjament enzimàtic l'atmosfera composta per 5 kPa O2 (balanç N2). Aquesta atmosfera va mantenir la qualitat visual del caqui tallat dins del límit de comercialització durant 7-9 dies a 5 ºC. Per contra, l'aplicació d'altes concentracions de CO2 (10 ó 20 kPa) va donar lloc a un pardetjament en certes zones de la polpa, el qual és conegut com 'internal flesh browning'. Estudis posteriors van confirmar l'efecte beneficiós de l'envasament de caqui tallat i tractat amb solució antioxidant (CA-CaCl2) en una MAP activa de 5 kPa O2 millorant la qualitat visual de la fruita front a l'aplicació de una MAP passiva. El desenvolupament de recobriments comestibles amb capacitat antioxidant es va realitzar mitjançant la incorporació d'antioxidants (CA-CaCl2) en formulacions a base de proteïna de sèrum làctic (WPI), proteïna de soia (SPI), hidroxipropilmetilcel-lulosa (HPMC) i pectina. Tots els recobriments van ser efectius controlant el pardetjament enzimàtic del caqui tallat. No obstant, les mostres recobertes amb HPMC i pectina van ser millor avaluades visualment que la resta de tractaments. En general, el processat, l'aplicació d'antioxidants, l'envasament en atmosferes controlades i els distints recobriments comestibles estudiats, si bé no van mostrar un efecte clar en els paràmetres de la qualitat nutricional avaluats, no van tindre un efecte negatiu en els mateixos. Per altra banda, els fruits recol¿lectats a final de temporada van tenir major activitat antioxidant i contingut en
Sanchís Soler, E. (2016). Effect of processing on the physicochemical, sensory, nutritional and microbiological quality of fresh-cut 'Rojo Brillante' persimmon [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62588
TESIS

碩士
國立中興大學
機械工程學系所
104
This study proposes a non-enzymatic glucose sensor fabricated by utilizing photolithography commonly used in the semiconductor industry. First, an ordered array of microhemispherical features was formed on a 6-inch regenerated silicon wafer through photolithography. Next, a thin gold layer was sputtered onto the hemispheres and then gold nanoparticles were uniformly deposited via sol-gel to form a microstructural composite sensing electrode substrate for electrochemistry. It was observed from the results that the effective sensing area of the proposed glucose sensor was 10.2 times greater than a planar gold electrode. Further investigation revealed that the sensor’s linear detection range for glucose was from 55.6 µM to 13.89 mM, with a sensitivity of 749.2 µA·mM-1·cm-2 and a detection limit of 9 µM. In addition, the proposed sensor can also effectively detect changes in glucose levels to an accuracy of ±0.18 mg/dL; far greater than the FDA specification of ±20 mg/dL and ISO15197 specification of ±15 mg/dL. The simple and low-cost manufacturing combined with a high sensitivity, enzyme-free and excellent sensing performace indicates that the proposed non-enzymatic glucose sensor is commercially feasible.

碩士
國立高雄應用科技大學
化學工程與材料工程系博碩士班
103
Abstract (1) Pd-Pt multi-armednanocubes as non-enzymatic glucose sensor Pd-Pt multi-armed nanocubes were preparedand successfully used as catalysts for being a non-enzymatic glucose sensor. Compared with the Pt nanoparticles, Pd-Pt multi-armed nanocubes exhibited a higher electrochemically real surface area and greater catalytic activity on glucose oxidation.Furthermore, the Tafel analyses demonstrated that the exchange current density for the Pd-Pt multi-armednanocubes was 1.8×10-2 mA / cm2, greater than 1.51×10-2 mA / cm2 for Pt nanoparticles and 1.29×10-2 mA / cm2 for Pd nanocubes. Additionally, the ampermetric analyses showed that the sensitivity and linear range for Pd-Pt multi-armed nanocubes were 170 μA mM-1 cm-2 and 0.3-6.8 mM, respectively, whereas Pt nanoparticles had 45.7 μA mM-1 cm-2 forsensitivity and 0.3-5.2 mM for sensing linear range. The Pd-Pt multi-armed nanocubes showed the better sensitivity and linear range for sensing glucose without need enzymes. (2) Cubic, octahedral, and rhombic dodecahedral Palladium nanoparticles as catalyst for glucose oxidation reaction and sensing glucose Pd nanocubes enclosed with (100) planes, Pd nanooctahedrons enclosed with (111) planes, and Pd nanododecahedrons enclosed with (110) planes were preapred and used as catalysts for glucose oxidation reaction (GOR) and non-enzyamtic glucose sensor. The cyclic voltammetric measurements for GORs showed that the specific activity in terms of electrochemical surface area for Pd nonacubes was 3089.6 μC cm-2, 2.97 times and 3.6 times higher than Pd octahedron (1040.6 μC cm-2) and Pd rhombic dodecahedron (847.75 μC cm-2), respectively. The Pdnanocubes enclosed by (100) planes exhibited better activity in GOR. Furthermore, the ampermetric analyses showed that Pd nanocubes for sensing glucose displayed two linear ranges: 0.5- 10 mM and 11-20 mM.The sensitivities for Pd nanocubes were 0.0197 mA mM-1 cm-2 and 0.0095 mA mM-1 cm-2 in the first and latter linear range. (3) Diameter effect of electrospun carbon fiber support for the catalysis of Pt nanoparticles in glucose oxidation Electrospun carbon fibers (CF) with diameters of 39 nm (CF39nm), 158 nm (CF158nm), and 309 nm (CF309nm) were used as Pt-catalyst supports for a glucose oxidation reaction. Based on experimentally balanced comparisons using electrochemical methods, CF39nm with higher curvature and smaller diameter had a greater number of Pt atoms on the surface. Compared with the CF158nm and CF309nm systems, CF39nm has a higher electrochemically real surface area and greater catalytic activity on glucose oxidation. The Tafel analyses demonstrated that the exchange current density for the CF39nm system was 9.08×10-3 mA / cm2, greater than 8.41×10-3 mA / cm2 for CF158nm-supported Pt nanoparticles and 7.39×10-3 mA / cm2 for CF309nm-supported Pt nanoparticles. In addition, as data supporting the catalytic characterization for glucose oxidation, all of the CF-supported Pt nanoparticles showed remarkable tolerance to foreign substances in the application of a non-enzymatic glucose sensor, where CF39nm-supported Pt nanoparticles (Pt/CF39nm) showed a higher sensitivity (2.03 A∙mM−1∙cm−2), detection limit (33 M), and linear range (0.3–17 mM). The high recovery by serum sample analyses further confirmed the potential of Pt/CF39nm as a glucose sensor. The promising results showed the feasibility of these electrospun CFs being applied for both glucose fuel cells and non-enzymatic glucose sensors.

碩士
國立雲林科技大學
電子工程系
105
Zinc oxide is an inorganic compound which is wide band gap II-VI compound semiconductors, it’s has a wide-direct band gap 3.37 eV at room temperature ,large exciton binding energy 60 meV and high chemical and thermal stability. In the other hand, it’s have an advantage like high thermal stability, low melting points and suitable for growth of nanostructure. High isoelectric point allowed ZnO as a good biocompatibility and high electron mobility and its low toxicity thus have great potential for non- enzymatic glucose sensing. In this work, doped with group III elements (Gallium), which were decreases the resistivity, increase the carrier concentration and lower electron mobility while with doping. By using doped methods is a relatively cheap and simple over the other enhancement methods. This study was divided into three phases. The first stage is ZnO nanorods were synthesized by hydrothermal growth technique. The second stage is ZnO doped Ga were mixed at different proportions, which were compared with pure ZnO nanorods. The third stage is high surface-to-volume ratios of gallium lead to enhancement and development of non-enzyme glucose sensor. The surface morphology and physical properties were characterized by SEM, TEM and X-ray, respectively. Sensing response to compared in a 0~10mM glucose solution with gallium doping and without doping by using cyclic voltammetry method. The glucose sensor with gallium doping show a 35.5 (μA/cm2-mM) and Correlation coefficient (R2) 0.994, compared with the pure ZnO nanorods were 27.28 (μA/cm2-mM) and Correlation coefficient 0.983. On the other hand, samples with different surface-to-volume ratios were obtained by changing the various hydrothermal reaction times, the superiority of gallium doping glucose sensor under hydrothermal reaction 6 hours have the high sensitivity and accuracy is attributed mainly to the high surface area and higher conductivity.

碩士
國立臺北科技大學
化學工程研究所
102
Nowadays Glucose detection is of great importance in the fields of biological, environmental, and clinical analyses. In this research, we report a zinc oxide ( ZnO ) nanorod powder surface coated with carbon material for non-enzymatic glucose sensor applications through hydrothermal process and chemical vapor deposition method. A series of tests including crystallinity analysis, microstructure observation and electrochemical property investigations were carried out. For the cyclic voltammetric ( CV ) glucose detection, the low detection limit of 1 μM with linear range from 0 μM to 10 μM. With such good analytical performance from simple process, it is believed that the nanocomposites composed of ZnO nanorod powder surface coated with carbon material are promising for the development of cost-effective non-enzymatic electrochemical glucose biosensors.

碩士
國立雲林科技大學
電子工程系
106
In this study, inorganic metal oxide semiconductors were used as the subject, and the glucose area was increased by the nanostructure method. This was used as the non-enzyme glucose sensing electrode, and the disadvantages of the enzyme electrode were improved and promote electrochemical detection the reaction sensitivity and stability of glucose. The study was divided into three stages. The first-stage used a hydrothermal method to prepare a zinc oxide nanorods for comparative measurement of glucose sensing sensitivity under different concentrations of sodium hydroxide solution. In the second-stage, blend different aluminum ratios for doping that the concentration of electron carriers was increased and the sensing catalytic ability was effectively promoted. and the ratio of the best-doped aluminum is found that it as the non-enzymatic glucose sensing electrode and compared with the first-stage zinc oxide nanorods. The third-stage use optimal doping ratio in second stage to.develop an optical glucose sensor. By physical property analysis (scanning electron microscopy and X-ray diffraction analysis), the nanostructured morphology and elemental content were observed, and the factors of effecting the sensor were more accurately known. In addition, electrochemical characteristics of zinc oxide nanorods at different doping amount were observed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). After being improved by doping aluminum element, to measure the different concentration of glucose solution (0-12 mM) and sodium hydroxide solution (0.1 M) of cyclic voltammogram. It was found that the optimal aluminum doping have a high sensitivity of 83.2 (μA/cm2-mM) and a determination coefficient (R2) of 0.993. In the first-stage to analysis different concentration of sodium hydroxide to increase the sensitivity and observed in the second-stage that the doping 1.0% of aluminum atom would occupy the lattice gap due to the difference between the radius of zinc atoms and aluminum atoms that cause the distorted deformation of the crystal lattice of the zinc oxide, so that increase the scattering of the carrier at the grain boundary leads to a decrease in Hall mobility the Hall mobility decreases, and the decrease in the surface area causes the conductivity to be slightly higher than doping the 0.5% of aluminum atoms and the sensitivity is down, and doping 0.5% of aluminum atoms with the best of more appropriate body surface area conductivity and sensitivity. Although doping 0.1% of aluminum ions with a higher body surface area, a little amount of aluminum ions makes the poor conductivity and worst sensitivity. To make the three-stage light glucose sensor by stage-two doping optimal parameters that the sensitivity of 94.9 (μA/cm2-mM) and a determination coefficient (R2) of 0.994.

碩士
國立清華大學
工程與系統科學系
106
Yeast fermentation products contain multiple ingredients such as succinate, pyruvate, and acetate; and high performance liquid chromatography (HPLC) is commonly applied to the monitoring of these compositions. However, applying lab-scale fermentation for optimizing the process or screening high-yield strains can be time consuming, labor intensive, and sample devouring. Microfluidic platforms are currently more favorable setups for early-stage screening and optimization. Nonetheless, the minute sample amount in microfluidic setup is challenging for HPLC analysis. Therefore, this study focuses on the development of micro-sensors for rapid and high dynamic range detections not only in performing the monitoring of the metabolic products (lactic acid, ethanol…etc.) and the substrate (glucose) but also the pH environment in the micro-scale fermentation. The micro-sensors utilized the NiONPs/GO/Nafion/Au electrode and NiONPs/GO/Nafion/SPEs for detecting metabolic products and substrates while the IrOx electrode for pH measurements. Two kinds of microelectrodes, gold and screen-printed carbon, were applied and their performance was compared. Both electrodes had a linear detection range of 1 – 50 mM for lactate detection but the sensitivity of screen-printed carbon electrode had a sensitivity of 11.74±1.05μA/mM, which was two folds higher than the gold electrode. The screen-printed electrode also had good performance in ethanol detection: the detection range was 1 – 50 mM and the sensitivity was 13.70±1.84μA/mM. However, the screen-printed carbon electrode was highly prone to poisoning in glucose detection. The gold electrode showed stable detection of ethanol and glucose in 17 days. The glucose detection had a detection range of 1 - 20mM and a sensitivity of 27.09±3.04μA/mM. Both gold and screen-printed electrodes had a linear detection range for pH value from pH 2 to pH 10 with a sensitivity of 54 mV/pH. All detections were highly linear with correlation coefficients higher than 0.99.

碩士
國立成功大學
微電子工程研究所
107
In this research, the fabrication of Ni-Au alloy nanowire for non-enzymatic glucose sensor on p-silicon based anodic aluminum oxide (AAO) template is discussed. The Ni-Au alloy nanowire is applied on an electrochemical glucose sensor. The Ni-Au alloy nanowire was fabricated via the self-made AAO template grown on the p-type heavily doped silicon substrate. The advantages of AAO on silicon are lower cost, stronger mechanical and less production time consuming comparing to traditional AAO grown directly by using aluminum. The electrodeposition of the Ni-Au alloy nanowire was fabricated by three-electrode system and pulse signals. The best parameter of Ni-Au alloy nanowire electrodeposition is (-1.6)V、PH2.0 and duty cycle 10%. To remove the AAO template after depositing, 2M alkaline medium was used in 30℃. The Ni-Au alloy nanowires exhibit high uniform arrangement. Further, use the Ni-Au alloy nanowires for the application of glucose measurement. After a successive injection of glucose and other substantial for measurement, the Ni-Au alloy glucose sensor exhibited a linear range of 0-3mM, a sensitivity of 1893 μA/mMcm2, and a detection limit of 1μM. Simultaneously, a superior selectivity and at least 30 days stability was also observed. The characteristics show that Ni-Au alloy nanowire has an excellent performance for glucose sensing.

碩士
國立臺灣科技大學
化學工程系
100
Cuprous oxide (Cu2O) nanocubes were synthesized in this study as electrocatalysts for the non-enzymatic glucose sensing. The particles size and shape of Cu2O was controlled through adjusting the concentration of CTAB (cetyltrimethylammonium bromide) which is a cationic surfactant. The capability of catalyzing glucose was investigated by electrochemical analyses and physical-chemcial characterizations. Due to the problem of interference might be resulted from the metal catalysts which can react with electroactive substrates, this work mixed Nafion and cellulose acetate (CA) to serve as an anti-interference layer for the modification of the surface of electrodes and to increase the selectivity. Moreover, the pH value of the analytes and the applied potential were further studied. The electrochemical analysis, mainly based on cyclic voltammetry and chronoamperometry method, investigated the performance of glucose catalyzing. The physical characteristics of the Cu2O nanocubes were studied by Transmission Electron Microscopy (TEM), Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), and Electron Spectroscopy for Chemical Analysis (ESCA). Finally, it was found that Cu2O nanocubes synthesized by using 0.04 M CTAB was the optimized concentration for catalyzing glucose, and the optimal ratio of Nafion:CA is 0.5:0.5 (wt.%) for the surface protection layer on the electrode. The optimized amperometric biosensor covered a wide linear detection range of glucose, from 0.5 to 9 mM (R2=0.997), at 0.6 V vs. Ag/AgCl of applied potential. Moreover, a sensitivity of 202.36 μA mM-1 cm-2 and a rapid response time (＜6 s) were obtained for the as-prepared non-enzymatic glucose sensor. We herein reported a glucose biosensor with surface decorated with Cu2O nanocubes for promising detection performance with good repeatability and high sensitivity.

碩士
國立雲林科技大學
電子工程系
107
The research is about using precious metal nanoparticles modified Cu2O/AZO composite on ITO glass ,and successfuly applied in non-enzymatic Glucose Sensor. There’re four parts of the experiment: First, coating different thickness of Aluminum-doped Zinc Oxide (AZO) seed layer for growing AZO nanorod arrays by hydrothermal method, then using SEM and XRD analyzed the best seed layer parameter. Second, electrodepositing Cuprous oxide (Cu2O) on AZO nanorod, and measured the best parameter for deposited Cu2O on AZO nanorods, then using XPS to analyze the Oxidation state of pH value in Cu2O precursor solution, and measuring the best deposition time. Third, chemical synthesis Au, Ag nanoparticles, and using UV-Vis absorption spectrum and SEM to get the best particle size, also through the Nafion to evenly dispersed on the surface of Cu2O/AZO NR, Last, analyzing its’ Redox reactions characteristic through the electrochemical analyzer, and also the best sensitivity, linearity and accuracy. Selecting the concentration of glucose 0, 50, 100, 150, 200 (mg/dL) which are match the human blood glucose to do the Cyclic voltammetry (CV) of electrochemical analyzer. Then linear fitting the relation of concentration and current on Cu2O/AZO NR/ITO composite to get its’ change slope is 26.117 and the coefficient of determination (R2 ) is 0.9424. Using Nafion to disperse Au, Ag nanoparticles to let the nanoparticles spread on the surface of sensor for helping its’ interface be stable, the slope increased to 27.456 and the R2 is up to 0.9643 by modified with Au nanoparticles. To measure the reaction of current in changing concentration through the Chronoamperometry (CA) ,when working potential in 0.6V can get the best sensitivity in 12.3 (221.6 ) with modified by Ag nanoparticle, and the linear range is to 60 – 200 mg/dL (3.33 – 11.11 mM) and the R2 is up to 0.997, thus, it’s suit to sense blood sugar of human body.

碩士
國立臺灣科技大學
化學工程系
104
The development of effective strategy to perform electrochemical determination of l-cysteine (L-cys) is of great importance for physiological and clinical diagnosis of various diseases owing to the abnormal level of L-cys. In this study, the application of electrochemical method aim to perform simple, accurate, and fast detection of L-cys using glassy carbon (GCE) and gold electrodes (AuE). Since direct use of bare GCE and AuE possessed problems of insufficient sensitivity and specificity, two designs of sensors for electrochemical determination of L-cys which are copper-silver fibers composite (500-Ag-Cu/PVP fibers) incorporated in Prussian blue-chitosan modified on GCE (Cu-Ag-PB-Chi/GCE) and copper electrodeposited on AuE (Cu/AuE) were prepared in order to address those problems. The modified layer of GCE was made under three steps: (1) preparation of 500-Ag-Cu/PVP fibers involving electrospinning, crosslinking, thiol-functionalization, silver-ions loading, heat reduction and copper electroless plating, (2) chemical synthesis of PB, and (3) preparation of chitosan solution (Chi). The as-prepared 500-Ag/PVP fibers, 500-Ag-Cu/PVP fibers, chemically synthesized PB, and Chi were used to fabricate: PB-Chi, Ag-PB–Chi, and Cu-Ag-PB–Chi/ GCE. The surface modification on the electrodes were evaluated by different analytical methods. Surface morphology observation by SEM revealed that after heat reduction allow to load silver-ions on PVP fibers (Ag+-RSH-CL-PVP fibers), where the structure of fibers was maintained. Meanwhile, by means of copper electroless plating, the 500-Ag-Cu/PVP fibers which possessed thicker average diameter than 500-Ag/PVP fibers was generated. The thiol-functionalization process was confirmed by FTIR that the peaks corresponded to the functional group of Si-O-Si and Si-O-CH3 were found. Moreover, XRD pattern results declared that the as-prepared 500-Ag/PVP and 500-Ag-Cu/PVP fibers reveal the crystalline phases of Ag and both Cu and Ag, respectively. The three modified GCE were characterized by cyclic voltammetry to investigate the current responses toward L-cys. The results of CV response of L-cys revealed the following findings: (1) PB-Chi/GCE was the least sensitive to L-cys, (2) Ag-PB-Chi/GCE exhibited higher current response than that of PB-Chi/GCE (1.2 times fold higher), and (3) Cu-Ag-PB-Chi/GCE owned a significant increase of sensitivity toward L-cys, as compared to that of PB-Chi (1.8 times fold increase) and Ag-PB-Chi/GCE (1.5 times fold increase). This improvement implied the contribution of synergetic effects of catalytic behavior of 500-Ag-Cu/PVP fibers in electrooxidation of L-cys. The sensing performance of Cu-Ag-PB-Chi/GCE was examined by amperometric test under optimized conditions. The Cu-Ag-PB-Chi/GCE showed two linear ranges over conentrations of 40-1800 and 1800-2500 µM with corresponding sensitivities of 0.1501 and 0.0707µA.µM-1cm-2, respectively, with the detection limit of 1.42 µM. According to interference tests, Cu-Ag-PB-Chi/GCE was selective toward L-cys and showed negligible response to sucrose, glucose, citric acid, oxalic acid, urea (concentration ratio L-cys to interferent= 1:1), uric acid, and EDTA (concentration ratio L-cys to interferent= 10:1). The second objective of this thesis is to prepare L-cys sensor based on Cu/AuE. The Cu/AuE was developed by potentiostatic deposition of metallic Cu from a precursor solution onto AuE. The surface morphology and crystallinity of the Cu/AuE were studied by SEM and XRD, respectively. According to SEM observation, the homogeneous coverage of copper layer on AuE was obtained for longer deposition time (≥ 480 s). In addition, dendrites structure of copper can be produced when high overpotential (≤ -0.7 V) was applied. XRD pattern of Cu/AuE confirmed that copper was successfully electro-deposited on the surface without the presence of its corresponding oxide forms. For further assessments, AuE was electrodeposited at -0.4 V for 480 s from solution containing 0.005 M of CuSO4 and 0.3 M Na2SO4, concerning the highest amperometric response resulted from Cu/AuE farbricated under these parameters. The electrochemical characteristics of Cu/AuE were investigated using cyclic voltammetry tests. Based on CV results, the Cu/AuE displayed a prominent anodic peak ascribed for electrooxidation of L-cys, indicating greater electrooxidation activity toward L-cys than bare AuE. The amperometric test run under optimized conditions showed that the Cu/AuE had lowest detection limit of 0.21 µM and two linear ranges between 1-400 and 400-1800 µM with corresponding sensitivities of 1.0493 and 0.5090 µA.µM-1.cm-2, respectively. Additionally, the Cu/AuE also exhibited high specificity to L-cys, as minor influence from sucrose, glucose, citric acid, oxalic acid, urea, EDTA (concentration ratio L-cys to interferent= 1:1), and uric acid (concentration ratio L-cys to interferent= 40:1) to the L-cys signal.

碩士
元智大學
光電工程學系
105
In this study, we integrated an enzymatic glucose sensor and a pair of holographic grating into a circular heterodyne for measuring the glucose concentration. According to the optical configuration, the auto-collimation system can be achieved. The measurement results showed that the best sensitivity of the proposed system was approximated of 0.6688 mg/dl as the optimum measurement conditions were selected. The response time of the proposed system can be shorter than 2.5 sec and the usage count of the proposed sensor can be more than 50 times.

碩士
國立中興大學
化學系
91
Glucose is an important biological compound. To improve the current methods to determine this compound, an infrared (IR) chemical sensing method was developed in this work. Because glucose exhibits high polarity and the samples containing this compound are usually very complex, sensitivity and selectivity are the major considerations in determination. To heighten the sensitivity in detecting this compound with the IR sensing method, a two-layer modification method was developed, in order to eliminate the problem associated in conventional IR sensing methods. To increase selectivity, glucose oxidase was employed. Through a flow injection system, the reaction product, gluconic acid, was easily detected by the IR sensing system developed in this work. To optimize the detection system, factors such as the response time, the effect of pH in the solution, the influence of flow rate, the efficiency in regeneration of the sensing device, and chemical interferences were investigated. The results indicated that the response time can be shorter than 2. Meanwhile, pH influenced the analytical signals significantly and the most suitable pH was around 5. In the examined range of flow rate, results indicated that flow rate was not significant. By examining the analytical of glucose in a solution containing fructose or sucrose, results indicated that the influences were limited. Using optimal conditions, the linear regression coefficients in standard curve can be higher than 0.99 for a concentration range from 0.1 mM to 10 mM.

碩士
國立雲林科技大學
電子工程系
106
The non-enzymatic glucose sensor was successfully prepared in this research which the single-wall carbon nanotubes (SWCNTs) were wrapped with Nafion to enhance the sensitivity of sensor based on the copper(I) oxide (Cu2O) surface modification of zinc oxide nanorod (ZnO NR)/Graphene composites on ITO glass. The experimental procedure of this research has four steps: First, the different sputtering time was used to deposit the ZnO seed layer, and then will be synthesis ZnO NR by hydrothermal. The morphology of ZnO NR was checked by scanning electron microscope (SEM). Secondly, the optimal cupreous time of Cu2O on the ZnO NR would be verified by electrochemistry with the different concentration of glucose. Thirdly, the SWCNTs wrapped with Nafion was dropped to Cu2O /ZnO NR to increase the catching ability of the glucose and checked by electrochemistry. Lastly, graphene would be prepared on the ITO glass and then fabricated the Cu2O surface modification of ZnO NR/Graphene composites. In the electrochemistry measurement, 0.1M NaOH was used as the electrolyte, and there were four concentrations of glucose: 0, 100, 150 and 200 mg dL-1. The electrochemical characteristics of the sensors were investigated by cyclic voltammetry (CV). The results showed the modified electrodes of Cu2O/ZnO NR had a linear response to glucose concentration and the maximum concentration could reach to 200 mg/dL with the sensitivity of 0.6207 μA mg-1 dL cm-2(about 11.17 μA mM-1 cm-2). Because the SWCNTs wrapped with Nafion could enhance the capturing ability of glucose checked by the CVs curve of electrochemistry. Since, the modified electrodes of SWCNT/Cu2O/ZnO NR has the optimal linear range from 0 to 200 mg/dL and good sensitivity of 16.1 μA mg-1 dL cm-2(289.8 μA mM-1 cm-2). Anyway, the SWCNTs wrapped with Nafion could increase the sensitivity of glucose sensor. The chronoamperometry (CA) is a precision real time response of the glucose sensor. So the graphene was fabricated on the ITO glass to adhesive on the SWCNTs/Cu2O/ZnO NR/Graphene composites as the glucose sensor, then the sensor would be tested by the CA method with the increasing the glucose concentration. The calibration curve of glucose sensor has two linear ranges: 0-5.556 and 5.556-11.111 mM and have the sensitivity of 466.1 and 203.1 μA mM-1 cm-2, respectively. The addition of graphene could increase the sensitivity at low concentration and reduce the response time (< 2 s) for the SWCNTs/Cu2O/ZnO NR glucose sensor.

Research on the cure and early detection of diseases such as diabetes, Alzheimer's, and Parkinson's is becoming of great interest due to the increasing number of people affected by them every year. An accurate and quick detection of various damaging species is highly critical in treatments of such diseases not only for exploring possible cures but also for early detection. If these diseases are detected during the initial stages than the possibility of curing them is much higher. Motivated by this, many researchers today have developed numerous types of sensing devices that can detect various physiological and biological compounds. However, most of these sensors are enzyme based. They have several setbacks such as the lack of sensitivity, restricted selectivity, short shelf life, and biological fouling. To overcome these obstacles, we examine the use of nanoceria modified Pt and Au electrodes for the detection of glucose and reactive oxygen species such as hydrogen peroxide. Amperometric detection of glucose and hydrogen peroxide is critical for biological applications for diabetes and possible Alzheimer's and Parkinson's patients. This dissertation focuses on the exploration of non-enzymatic detection of glucose and reactive oxygen species which has the prospective to be used for biological applications, in addition to an investigation of an odor control technology that uses these reactive oxygen species for the treatment of wastewater plants. The combination of bi-metallic composites with nanoceria showed increased oxidation ability towards glucose and hydrogen peroxide. The following dissertation expands on the relationship between bi-metallic nanoceria composite materials and its electro-oxidation of glucose and hydrogen peroxide towards biological sensing along with an investigation of an odor control technology that utilizes generates hydroxyl radical fine particle mist for the degradation of hydrogen sulfide odor in wastewater treatment plants.
Ph.D.
Doctorate
Chemistry
Sciences
Chemistry

碩士
國立臺灣科技大學
化學工程系
106
Diabetes mellitus was known as one of the important diseases which is difficult to deal with. Monitoring the blood glucose level for diabetes mellitus patients would be the solution to treat and prevent the patients from the complications that may occur. Glucose electrochemical biosensor is one of devices that were applied to monitor blood glucose level. Glucose detection using electrochemical analyses usually involved two methods. The first method is based on the direct electrooxidation ability of glucose by electrode and the other is based on the electroreduction ability of hydrogen peroxide that was produced from the oxidation of glucose by enzymes, e.g. glucose oxidase. In this study, the bare glassy carbon electrode, platinum wire, copper wire, and copper electrodeposited on platinum wire were developed to prepare simple, fast, and accurate platform for the detection of hydrogen peroxide and glucose. Because platinum and copper both show good electrocatalytic character toward hydrogen peroxide and glucose, the combination of platinum and copper as a biosensor is supposed to provide the synergetic effects to enhance the sensitivity for the sensing. In this study, copper particles were coated on platinum wire (Pt wire) using electrodeposition technique under different applied voltages. The surface morphology of the copper decorated Pt wire was observed by FE-SEM, which revealed that the copper particles were uniformly attached on the surface of Pt wire. Moreover, at the higher applied potential (-0.4 V), dendrites structure of copper was observed. The electrochemical characteristics against hydrogen peroxide and glucose were investigated using cyclic voltammetry in PBS with pH 7.4 and 0.1 M NaOH solution for different working electrodes, respectively. The results of cyclic voltammograms showed that both the reduction and the oxidation peaks increased by the incorporation of copper as a result of electrodeposition. The amperometric tests against hydrogen peroxide were conducted at around -0.3 V and -0.4 V in PBS with pH 7.4 and the results showed that the sensitivity increased significantly from 0.19 to 3.17 mA.mM-1.cm-2 for the bare Pt wire and the copper electrodeposited Pt wire at -0.4 V when the copper precursor solution was consisted of 50 mM CuSO4 in 0.5 M H2SO4 ((-0.4V)S-Cu/Pt wire). Furthermore, the amperometric test against glucose was performed in 0.1 M NaOH solution at 0.6 V. The sensitivity increased significantly, from 0.004 to 1.37 mA.mM-1.cm-2, by the incorporation of copper on Pt wire at -0.4 V. The highest sensitivity of (-0.4V)S-Cu/Pt wire was attributed to the increasing specific surface area after deposition of copper particles on the surface of Pt wire, followed by generation of higher electrocatalytic active sites on the surface. In addition, the sensitivity of (-0.4V)S-Cu/Pt wire was compared at the same applied voltage (0.6 V) and electrolyte solution (0.1 M NaOH) with other modified electrodes. The proposed sensor based on (-0.4V)S-Cu/Pt showed superior electrochemical performance with high sensitivity and simple and low-cost fabrication process. Moreover, Cu particles successfully overcome the disadvantages of Pt wire associated with lack of sensitivity and surface poisoning.

With the rising prevalence of diabetes, effective means of successful management of blood glucose levels are increasingly important. To improve on the ease of measurements, new technology is being developed to enable less invasive measurements. Some recent efforts have focused on the development of optical microscale glucose sensing systems based on the encapsulation of glucose oxidase within microspheres coated with polyelectrolyte multilayer nanofilms. In such sensors, a phosphorescent oxygen indicator is also co-encapsulated with the enzyme inside so that when glucose is present, glucose oxidase within the sensor reduces the local oxygen levels, causing a corresponding change in the luminescence intensity of the sensors. To test the aforementioned factors, a two-substrate, 2D FEM model of microscale optical glucose sensors in the dermis was developed. The model was used to predict the response time and sensitivity of glucose sensors with varying number and spacing of particles distributed in the dermis and varying physiological characteristics of the surrounding tissue; specifically, capillary density, blood vessel location relative to sensor, and glucose and oxygen consumption in tissue. Simulations were conducted to determine the magnitude of the change in the response time of sensors. Because the steady-state oxygen concentration within the sensors for a given blood glucose level determines the signal output, steady-state concentration of oxygen within sensors and the surrounding tissue for the entire physiological glucose range was evaluated. The utility of the model to predict the performance and efficacy of the sensors in the event of a host response to the foreign body implant was also evaluated. Simulations were performed to evaluate changes in sensor response and sensitivity in the occurrence of inflammation and progression of fibrous encapsulation of various thickness and density. The results from these simulations have provided knowledge on the impact of physiological factors that can potentially degrade sensor function in vivo. Our results indicate that upon the occurrence of a host response, sensitivity is reduced while range is extended. Furthermore, using the model we have been able to determine which conditions in vivo improve response time, sensitivity, and the linear response range for these sensors.

碩士
國立臺灣大學
物理學研究所
105
Gas sensors and biosensors are hot topics in research in recent years. Graphene/ZnO/p-type silicon multiple heterojunctions is the main structure used in this work to serve as biosensors. By decorating uricase on graphene, uricase would conduct chemical reaction. Different concentration of uric acid would produce different number of chemical products with different reaction rate. The Fermi level would be changed when carriers were doped in graphene, which would result in band bending, and the measured electrical signal would be changed. Second part of this research is about patterned graphene heterojunctions. When uricase attaches on patterned graphene, we try to find out the relationship between different size of holes and sensitivity on the detection of uric acid.

碩士
國立臺灣科技大學
光電工程研究所
105
In this study, we report nickel (Ni) foam based non-enzymatic glucose sensors with graphene (G) and nickel hydroxide Ni(OH)2 as modifiers. The G/Ni foam was synthesized using chemical vapor deposition (CVD) process and two different routes were devised in the preparation of G/Ni(OH)2/Ni foam such as electroplating and hydrothermal methods. All the samples were then fabricated and used as working electrodes to measure various glucose concentrations. Thus, the results depict that best sensitivity was observed for electroplating based Ni(OH)2 foam exhibits the sensitivity of 11843.2 μAmM-1cm-2 and the LOD is 660.4 nM. While the hydrothermal based Ni(OH)2 foam which is 16799.6 μAmM-1cm-2 and the LOD is 624.7 nM. On the other hand, the addition of graphene into Ni(OH)2 foam enhances the conductivity and surface area of all samples. Thus, the best sensitivity of electroplating based G/Ni(OH)2 gives 16769.2 μAmM-1cm-2 , LOD is 609.3 nM, and the increasing ratio of sensitivity is 16.26 %. Whereas the hydrothermal based G/Ni(OH)2 is 17333.2 μAmM-1cm-2 , LOD is 686.5 nM, and the increasing ratio of sensitivity is 3.17 %. Furthermore, different kinds of LEDs (blue and green) were used to optimize the sensitivity of G/Ni(OH)2 based non-enzymatic glucose sensors. Among them, glucose sensors (both Ni(OH)2 and G/Ni(OH)2 foam) under blue LED shows striking improvement in sensitivity. It is because the electron transportation is increased in the presence of blue LED, and thereby increases the reaction of Ni(OH)2 and glucose, which also enhances the sensitivity. The best sensitivity of electroplating based Ni(OH)2 gives 12663.2 μAmM-1cm-2, LOD is 437.8 nM, and the increasing ratio of sensitivity is 6.92 %. Whereas the hydrothermal based Ni(OH)2 is 17323.2 μAmM-1cm-2 , LOD is 241.8 nM, and the increasing ratio of sensitivity is 3.11 %. The best sensitivity of electroplating based G/Ni(OH)2 gives 14136.4 μAmM-1cm-2 , LOD is 582.4 nM, and the increasing ratio of sensitivity is 2.67 %. Whereas the hydrothermal based G/Ni(OH)2 is 17931.2 μAmM-1cm-2 , LOD is 232.3 nM, and the increasing ratio of sensitivity is 3.45 %.

Ultra-high temperature processing of milk renders a product that is bacteriologically stable for several months at ambient temperature. Various factors have been reported to induce changes in UHT milk during storage and thereby limit the shelf life of the milk. Consequently, changes in the sensory and microbiological properties of low fat UHT milk were assessed over time at different temperatures to develop a model whereby the shelf life of the milk can be predicted in a short time-period. UHT milk was stored at 25°C and accelerating temperatures of 35°C and 45°C and evaluated for changes over 195 days (d). A multivariate accelerated shelf life test (MASLT) was applied to the descriptive sensory data and allowed the successful prediction of the shelf life at various temperatures, with the shelf life of milk stored at 25°C estimated at 211 d. Higher storage temperatures negatively affected the shelf life of the milk, with estimations of 73 and 27 d for milk stored at 35°C and 45°C, respectively. The shelf life obtained from the MASLT was validated using survival analysis where the acceptance or rejection of samples by consumers gave an estimated shelf life of 214 d. The acceptability of UHT milk depends on the sensory quality of the milk. Consumer perception and physico-chemical properties of low fat UHT milk of various ages were evaluated to determine the parameters associated with the deterioration of the milk. As the consumer liking for aroma, appearance, taste and overall liking decreased over time, the detection of positive attributes in the milk decreased, while the detection of negative attributes increased. Parameters associated with the deterioration of UHT milk, including increased titratable acidity, Maillard reaction products and enzymatic reactions, decreased pH and changes in the colour of the milk, increased over storage time. Although sufficient heat treatment and packaging with light and oxygen barriers prevent microbial and oxidative spoilage of UHT milk, there are no means of inactivating heat-stable enzymes in UHT milk. Subsequently, the ability of different protease inhibitors to reduce the activity of a native milk enzyme (plasmin) and enzymes produced by bacterial contaminants (Pseudomonas fluorescens, Bacillus licheniformis and B. lentus) was evaluated. Protease inhibitors extracted from soybeans (Glycine max (L.) Merr), marama beans (Tylosema esculentum (Burch) A. Schreib) and cowpeas (Vigna unguiculata (L.) Walp) were evaluated with regards to their ability to inhibit these enzymes in a buffer system and in low fat UHT milk. The legume protease inhibitors were effective in reducing the activity of plasmin and proteases produced by Bacillus spp., while it showed low inhibitory activity towards P. fluorescens proteases in a buffer system. In UHT milk, the same protease inhibition was observed, however, to a lesser extent as compared to inhibition in the buffer system. Overall, the results indicate that the sensory properties of low fat UHT milk can be used to predict the shelf life of UHT milk in accelerated storage using the MASLT. Survival analysis can also be successfully employed to determine the shelf life of low fat UHT milk. Increased storage time of low fat UHT milk is associated with a reduction in the liking and positive attributes associated with the UHT milk, and an increase in negative attributes and physico-chemical and enzymatic parameters related to the deterioration of milk. Legume protease inhibitors show great potential in preventing or reducing proteolytic activity of Bacillus proteases and plasmin that may cause both sensory and consistency defects in the UHT milk during storage.
Thesis (PhD)--University of Pretoria, 2015.
tm2015
Food Science
PhD
Unrestricted

碩士
國立臺灣科技大學
電子工程系
103
We have designed glucose sensors based on the use of highly conducting nitrogen incorporated diamond film (NDFs) electrodes grown by microwave plasma enhanced chemical vapor deposition. The post deposition of Ni(OH)2 and CuO on Pyramidal NDFs and plane NDFs, which reveal differences for the glucose detection. The systematic cyclic voltammetry measurements on the 100nm thickness of Ni(OH)2 on the pyramidal NDFs glucose sensors attains higher sensitivity properties(3070(μA mM-1 cm-2)) than those of Ni(OH)2(120nm)/plane NDFs(2444(μA mM-1 cm-2)) and CuO(75nm)/pyramid NDFs glucose sensors(1993(μA mM-1 cm-2)). In terms of stability, CuO/NDFs based sensors reveals much better stability than Ni(OH)2/NDFs based sensors. The CuO/NDFs test chips were decreased less than 10% however, Ni(OH)2/NDFs based sensors were decreased up to 36% after exposing in air at room temperature for 28 days. The higher sensitivity with high selectivity and reliable stability might be due to the use of the highly electrically conductive diamond film electrodes, which is responsible for good glucose sensing properties, and exhibits a significant degree of potential on the future bio-sensing applications.

碩士
國立中山大學
電機工程學系研究所
107
In this thesis, various copper sulfide (CuS) nanostructures composited with copper oxide (CuO) nanoparticles have been discussed. Nanocomposites are grown on the ITO substrates for non-enzymatic glucose sensing. Different morphologies and thicknesses of the sensing materials have significant effects to the sensitivity and the detection range of the sensors. Various CuS nanostructures are electroplated on the ITO substrate in this study. CuO nanoparticles are decorated on the surface of CuS for modification by RF sputtering system. The CuO/CuS nanocomposites are completed as a double-layered sensing material. By adjusting the concentration of the plating solution and changing the plating time, the morphology and the thickness of CuS can be controlled. We analyze the differences of the sensing material before and after the CuO modification. Sensing performances of the devices to glucose are also been compared. Based on the results, the sensing material CuS has the best performances by fabricating with 0.15M sodium thiosulfate pentahydrate under plating time of 900 s. Its sensitivity is 132.39μAmM-1cm-2. After the CuO modification, the sensitivity is further improved to 139.86μAmM-1cm-2. The results show that the CuO/CuS nanocomposites have higher sensing ability and wider detection range to glucose. It has great potential for biomedical detection.

碩士
國立中山大學
電機工程學系研究所
106
In this thesis, we investigated zinc oxide (ZnO) nanotubes/ITO glass substrate decorated with two different metal oxides’ nanoparticles (TiO2 and MnO2) for non-enzymatic glucose sensors. Firstly, a ZnO seed layer was deposited on ITO glass substrate by RF sputtering system. ZnO nanorods were then grown by hydrothermal synthesis. Alkaline etching solution was prepared to etch ZnO nanorods into nanotubes (ZnO NTs/ITO). In addition, TiO2 nanoparticles and MnO2 nanoparticles were also grown in this study. TiO2 and MnO2 nanoparticles were decorated on ZnO NTs by dip coating and drop coating respectively to complete the dip-coated TiO2/ ZnO/ ITO, the drop-coated TiO2/ ZnO/ ITO and the drop-coated MnO2/ ZnO/ ITO sensing elements. The ZnO NTs structure is used because it has a stable and excellent nano-scale morphology, which can effectively increase the contact area between the analyte and the electrode. With decoration of two different metal oxides, the sensing ability to glucose is effectively improved. The experimental results show that the 17.5mg drop-coated MnO2/ ZnO/ ITO sensing element has the best sensing performance to glucose. The sensitivity is 109.612μAmM-1cm-2, the value of R2 is 0.9959, and the linear sensing range is 0.1mM~7.0mM. The addition of interferents has an effect on the current of less than 10% and the response time is less than 3 seconds. Excellent glucose sensors for detecting diabetes is more accurately and quickly. It is also important to the development of food industry.

碩士
國立中興大學
動物科學系所
106
For these past few years, drip chicken essence has been more popular among the consumers. The increased profit gain has also stimulated the production. This has also produced more by-products in account to higher production of drip chicken essence. The previous study shows that the production rate of drip chicken essence from spent hens is about 35 %. In other words, the rest of meat residues account for 65 %.But the industry has yet to find a way to efficiently utilize the meat residues. The aim of the study is to clarify the anti-fatigue effect of drip chicken essence by-product hydrolysate, in hope to increase the value of the by-product of drip chicken essence. In the first study, chicken meat residues were hydrolyzed with three protease (enzyme A, enzyme B, enzyme C). Effects of hydrolysis conditions were studied through orthogonal experiment, and optimization hydrolysis conditions were obtained.The hydrolysate were used to evaluate anti-fatigue effect and probable mechanisms. Forty 6-week-old male ICR mice were randomly divided into five groups of eight mice each: a control group given distilled water, a meat extract group without enzymatic hydrolysis and low-dose(0.96 g/kg), medium-dose(1.92 g/kg), high-dose(4.8 g/kg) meat residue hydrolysate groups. Samples were administered by gastric intubation using a feeding atraumatic needle, once per day for 28 consecutive days. The average swimming time, hepatic glycogen and biochemical parameters were measured. Compared with the control group, all of the meat residue hydrolysate groups, especially the high-dose treatment prolonged the swimming time of mice (P ＜ 0.05). The 30 seconds muscle endurance score and the tensile force test showed the similar result with the swimming test. After swimming, the blood glucose and hepatic glycogen of control group and meat extract group were significantly lower than meat residue hydrolysate groups (P ＜ 0.05).The blood lactic acid, blood urea nitrogen and creatine phosphokinase concentration of control group were significantly higher than meat residue hydrolysate groups (P ＜ 0.05). In the second study, chicken meat residues were hydrolyzed with three protease (enzyme D, enzyme E, enzyme F). The Yield, degree of hydrolysis, peptide concentration, soluble protein concentration and sensory evaluation of meat residue hydrolysate were determined. The optimization hydrolysis conditions were obtained to prepare protein hydrolysate and Maillard reaction products. In summary, protein hydrolysis could remarkably increase the yield and peptide concentration of meat residue (P ＜ 0.05), especially the hydrolysate group of enzyme F. The Maillard reaction exhibited a distinctly enhanced effect on flavor and a greatly reduced bitterness. The sensory evaluation of Maillard reaction products prepared from hydrolysate of enzyme D exhibited the strongest umami tastes . As for overall acceptance, Maillard reaction products of enzyme D hydrolysate was better than other treatments.Conclusively, meat residue hydrolysate could alleviate physical fatigue without negative effects, and the Maillard reaction products could improve the flavor performance.

碩士
國立臺灣科技大學
電子工程系
106
In this study, we report nickel hydroxide (Ni(OH)2) and nitrogen incorporated ultrananocrystalline diamond (N-UNCD)/(Ni(OH)2) on copper foam for non-enzyme glucose sensor. Initially, the hydrothermal growth condition of (Ni(OH)2) was optimized to study their glucose sensing properties. It was revealed that the best sensitivity of hydrothermal Ni(OH)2 is 8257.6 µAmM-1cm-2 (0.5~2 mM), LOD is 2.492 μM. On the other hand, the Ni(OH)2/copper foam exhibits the low concentration glucose sensitivity of 18964 µAmM-1cm-2 (5~40μm), LOD is 2.141 μM, respectively. This result is 10 times better than the sensitivity of high glucose concentration measurements. The stability of the Ni(OH)2/copper foam was then measured after 7 days, which shows the decay of 28.5%. To overcome the decay of Ni(OH)2/copper foam electrode, N-UNCD was grown on copper foam with and without anneal. Thus, the highest sensitivity of Ni(OH)2 /N-UNCD/copper foam is 4753.6 µAmM-1cm-2 (0.5~2 mM), LOD is 2.179μM. However, despite the sensitivity of Ni(OH)2 /N-UNCD/copper foam is not as high as compared with the Ni(OH)2/copper foam electrode, still the stability of the annealed N-UNCD exhibits only 6 to 9% of decay after 7 days. This is because the chemical stability of N-UNCD in electrolyte solution and the electrocatalytic behavior of Ni(OH)2/copper foam. Furthermore, the synergistic effect between N-UNCD and Ni(OH)2/copper foam enhances the stability of Ni(OH)2/N-UNCD/copper foam electrode based glucose sensor.