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1
Arkhangelskiy, Artem. "Plasma-Assisted Deposition of Natural Polymers for Flexible Biosensor Applications." Doctoral thesis, Università degli studi di Trento, 2022. https://hdl.handle.net/11572/362102.
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Flexible biosensors have gained increased attention in the scientific and medical community in the last decades. They provide an easy and fast way of monitoring the physiological condition of the human body, collecting and analyzing different types of data according to their location. Flexible biosensors for health monitoring can be distinguished into 2 categories: implantable biosensors and wearable devices. Temperature, contraction, elongation, pressure, and motion together with a wide range of physiological metabolites, including lactate, cortisol, and other tiny ions can be measured from sweat or tears using biosensors attached to the skin. On the other side, for the detection of (bio)chemical analytes within the body, such as metabolites, proteins, and biomarkers, the implantable biosensor should be in contact with the biological environment, such as the surface of organs, the endothelial walls of veins, the brain connections together with the internal physiological fluids (blood, saliva, or cerebrospinal fluid). Flexibility and stretchability are the key characteristics of flexible biosensors, which enable adaptability to the physical dynamics and non-rigid environment of the human body and enhance the interaction between analytes and sensing elements. Moreover, specific applications require implantable or wearable biosensors to provide a high level of biocompatibility and also biodegradability together with the essential requirements of biosensors, such as accuracy, selectivity, sensitivity, repeatability, and stability. Biocompatibility is essential for both types of flexible biosensors to prevent any kinds of inflammation or adverse reaction of the device, while biodegradability is necessary for implantable biosensors to avoid additional surgical intervention to remove the device from the body.
To fulfill these requirements (flexibility, biodegradability, and biocompatibility), a diverse set of biocompatible and biodegradable polymers from synthetic and natural origins have been proposed for flexible biosensor production. Despite the advantages of synthetic polymers in terms of processing, stability, and mechanical properties, natural polymers are preferable for many applications due to their enhanced bioactivity, biodegradability, and biocompatibility. Among natural polymers, chitosan and silk fibroin have been widely investigated for biosensor production due to their remarkable properties, such as nontoxicity, and immunological activity. Different production approaches, from a thin coating deposition to the production of relatively big solid constructs, have been applied to natural polymers in order to achieve the necessary structure complexity for the realization of the biosensor structure. Generally, for flexible biosensors biopolymers have been proceeded into a film/layer/coating configuration as flexible substrates, electroactive (sensing) parts, or insulating layer. Despite the progress in the fabrication processes, the continuous evolution of flexible biosensors from 2-3 layered structures into multilayers structures requires the development of novel deposition/production methods for natural polymers in order to provide a high level of adhesion between layers, stability, and patterning capabilities. One of the possibilities is to use atmospheric plasma technologies, especially atmospheric pressure plasma jet (torch) (APPJ), that have been investigated for different types of biomedical applications. The increased attention got plasma processes related to surface cleaning, modification, and film
formation. The combination of etching and deposition might allow the
formation of the desired sensor structure. Moreover, cold plasma provides mild and technological processes at room temperature, with low changes in material properties.
The core of the thesis is to develop novel deposition methods for the production of flexible biosensors. A special focus is put on the plasma- assisted deposition of silk fibroin and chitosan, representing 2 different natural polymers structures, proteins, and polysaccharides respectively, for a wide range of applications: bioactive coatings with enhanced adhesion and stability with no need for pre or post-treatment steps; layered biofilms with the ability to control and guide cell behavior; PEDOT:PSS electroactive coatings for the realization of biosensor layered structures.
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Tur, García Eva. "Development of a flexible biosensor for the monitoring of lactate in human sweat for its medical use in pressure ischemia." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/9254.
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Pressure ischemia is a medical condition characterised by the necrosis of the skin and underlying tissues in body areas exposed to prolonged pressure. This condition leads to the development of bedsores and affects 9% of hospitalised patients, costing the NHS between £1.4 and £2.1 billion per year. The severity of pressure ischemia has been linked to the concentration of sweat lactate, a product of sweat gland metabolism under anaerobic conditions, such as hypoxia. Normal levels of lactate in human sweat are 20±7 mM, but under ischemic conditions these can rise up to approximately 70 mM.
This project presents the development of a novel flexible electrochemical enzyme-based biosensor for the continuous and non-invasive monitoring of sweat lactate with the potential for becoming a body-worn device for the early detection of pressure ischemia onset. The core of the recognition system is a flexible laminate, comprising two highly porous polycarbonate membranes, which provide support for the lactate oxidase enzyme, immobilised via covalent cross-linking. Oxidation of lactate produces H2O2, which is subsequently determined electrochemically. The transducer comprises a two-electrode system on a single flexible polycarbonate membrane, sputter-coated with gold (CE/RE) and platinum (WE) to render it conductive. The developed design has been improved through investigation into different factors regarding the immobilisation method of the enzyme in the laminate and the lowering of interferences from oxidising compounds present in sweat.
The sensing system exhibits lactate selectivity at physiologically relevant concentrations in sweat for pressure ischemia (0–70 mM), with good reproducibility (7.2–12.2% RSD) for a hand-manufactured device. The reliability of the sensor’s performance and the capability to detect lactate fluctuations on human sweat samples has been demonstrated. The sensing system showed excellent operational and mechanical stability. The application of Nafion® on the WE lowered interferences from ascorbic acid and uric acid by 96.7 and 81.7%
respectively. These results show promise towards the further development of a body-‐worn monitoring device for determining lactate levels in undiluted human sweat samples in a reproducible, fast and accurate manner.
3
Geitmann, Matthis. "Biosensor Studies of Ligand Interactions with Structurally Flexible Enzymes : Applications for Antiviral Drug Development." Doctoral thesis, Uppsala universitet, Institutionen för naturvetenskaplig biokemi, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5797.
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The use of a surface plasmon biosensor fills a missing link in kinetic studies of enzymes, since it measures directly the interaction between biomolecules and allows determination of parameters that are determined only indirectly in activity assays. The present thesis deals with kinetic and dynamic aspects of ligand binding to two viral enzymes: the human cytomegalovirus (HCMV) protease and the human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT). The improved description of interactions presented herein will contribute to the discovery and development of antiviral drugs. The biosensor method provided new insights into the interaction between serine proteases and a peptide substrate, as well as substrate-induced conformational changes of the enzymes. The direct binding assay served as a tool for characterising the binding mechanism of HCMV protease inhibitors. Kinetic details of the interaction between HIV-1 RT and non-nucleoside reverse transcriptase inhibitors (NNRTIs) were unravelled. The recorded sensorgrams revealed several forms of complexity. A general binding model for the analysis was derived from the data, describing a two-state mechanism for the enzyme and a high- and a low-affinity interaction with the inhibitor. Interaction kinetic constants were determined for the clinically used NNRTIs and several investigational inhibitors. The established method was applied to investigate the mechanism of resistance against NNRTIs. Amino acid substitutions in the NNRTI-binding site resulted in both decreased association rates and increased dissociation rates for the inhibitors. The K103N and the L100I substitution also interfered with the formation of the binding site, thereby facilitating inhibitor binding and unbinding. Finally, thermodynamic analysis revealed that, despite the hydrophobic character of the interaction, NNRTI binding was mainly enthalpy-driven at equilibrium. Large entropy contributions in the association and dissociation indicated that binding is associated with a dynamic effect in the enzyme.
4
Zhang, Panpan, Sheng Yang, Roberto Pineda-Gómez, Bergoi Ibarlucea, Ji Ma, Martin R. Lohe, Teuku Fawzul Akbar, Larysa Baraban, Gianaurelio Cuniberti, and Xinliang Feng. "Electrochemically Exfoliated High-Quality 2H-MoS₂ for Multiflake Thin Film Flexible Biosensors." Wiley-VCH, 2019. https://tud.qucosa.de/id/qucosa%3A73171.
Full textAbstract:
2D molybdenum disulfide (MoS₂) gives a new inspiration for the field of nanoelectronics, photovoltaics, and sensorics. However, the most common processing technology, e.g., liquid‐phase based scalable exfoliation used for device fabrication, leads to the number of shortcomings that impede their large area production and integration. Major challenges are associated with the small size and low concentration of MoS₂ flakes, as well as insufficient control over their physical properties, e.g., internal heterogeneity of the metallic and semiconducting phases. Here it is demonstrated that large semiconducting MoS₂ sheets (with dimensions up to 50 µm) can be obtained by a facile cathodic exfoliation approach in nonaqueous electrolyte. The synthetic process avoids surface oxidation thus preserving the MoS₂ sheets with intact crystalline structure. It is further demonstrated at the proof‐of‐concept level, a solution‐processed large area (60 × 60 µm) flexible Ebola biosensor, based on a MoS₂ thin film (6 µm thickness) fabricated via restacking of the multiple flakes on the polyimide substrate. The experimental results reveal a low detection limit (in femtomolar–picomolar range) of the fabricated sensor devices. The presented exfoliation method opens up new opportunities for fabrication of large arrays of multifunctional biomedical devices based on novel 2D materials.
5
Pal, Ramendra K. "Fabrication of flexible, biofunctional architectures from silk proteins." VCU Scholars Compass, 2017. http://scholarscompass.vcu.edu/etd/4995.
Full textAbstract:
Advances in the biomedical field require functional materials and processes that can lead to devices that are biocompatible, and biodegradable while maintaining high performance and mechanical conformability. In this context, a current shift in focus is towards natural polymers as not only the structural but also functional components of such devices. This poses material-specific functionalization and fabrication related questions in the design and fabrication of such systems. Silk protein biopolymers from the silkworm show tremendous promise in this regard due to intrinsic properties: mechanical performance, optical transparency, biocompatibility, biodegradability, processability, and the ability to entrap and stabilize biomolecules. The unique ensemble of properties indicates opportunities to employ this material into numerous biomedical applications. However, specific processing, functionalization, and fabrication techniques are required to make a successful transition from the silk cocoon to silk-based devices. This research is focused on these challenges to form silk-based functional material and devices for application in areas of therapeutics, bio-optics, and bioelectronics.
To make silk proteins mechanically conformable to biological tissues, the first exploration is directed towards the realization of precisely micro-patterned silk proteins in flexible formats. The optical properties of silk proteins are investigated by showing the angle-dependent iridescent behavior of micropatterned proteins, and developing soft micro-optical devices for light concentration and focusing. The optical characteristics and fabrication process reported in the work can lead to the future application of silk proteins in flexible optics and electronics.
The microfabrication process of silk proteins is further extended to form shape-defined silk protein microparticles. Here, the specificity of shape and the ability to form monodisperse shapes can be used as shape encoded efficient cargo and contrast agents. Also, these particles can efficiently entrap and stabilize biomolecules for drug delivery and bioimaging applications.
Next, a smart confluence of silk sericin and a synthetic functional polymer PEDOT:PSS is shown. The composite materials obtained have synergistic effects from both polymers. Silk proteins impart biodegradability and patternability, while the intrinsically conductive PEDOT:PSS imparts electrical conductivity and electrochemical activity. Conductive micro architectures on rigid as well as flexible formats are shown via a green, water-based fabrication process. The applications of the composite are successfully demonstrated by realizing biosensing and energy storage devices on rigid or flexible forms. The versatility of the approach will lead to the development of a variety of applications such as in bio-optics, bioelectronics, and in the fundamental study of cellular bio electrogenic environments.
Finally, to expand the applicability of reported functional polymers and composites beyond the microscale, a method for silk nano-patterning via electron beam lithography is explored. The technique enables one-step fabrication of user defined structures at the submicron and nano-scales. By virtue of acrylate chemistry, a very low energetic beam and dosage are required to form silk nano-architectures. Also, the process can form both positive and negative features depending on the dosage. The fabrication platform can also form nano scale patterns of the conductive composite. The conductive measurements confirm the formation of conductive nanowires and the ability of silk sericin to entrap PEDOT:PSS particles in nanoscale features.
6
Andersson, Simon. "Point-of-care beta-hydroxybutyrate determination for the management of diabetic ketoacidosis based on flexible laser-induced graphene electrode system." Thesis, Linköpings universitet, Sensor- och aktuatorsystem, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-179116.
Full textAbstract:
Diabetic ketoacidosis (DKA) is a life-threatening condition that can appear in patients with diabetes. High ketones in the blood lead to acidity of the blood. For DKA diagnosis and management, ketones such as hydroxybutyrate (HB) can be used to quantify the severity of the disease. The fabrication of electrochemical biosensors for the detection of HB is attractive since their capability to deliver fast response, high sensitivity, good selectivity and potential for miniaturisation. In this thesis, an integrated electrode system was prepared for the detection of HB. Laser-induced graphene (LIG) with a 3D porous structure was used as the flexible platform. Poly (toluidine blue O) (PTB) was electro-deposited on LIG (PTB/LIG) under the optimised conduction (pH of 9.7 and from 0.4 to an upper cyclic potential of 0.8 V). The single PTB/LIG working electrode demonstrated excellent performance towards the detection of NADH with a linear range of 6.7 M to 3 mM using chronoamperometry, high sensitivity of detecting NADH and excellent anti-fouling ability (94 % response current retained after 1500 s). Further integration of the 3-electrode system realised the static amperometric detection of NADH over the range of 78 M to 10 mM. Based on the excellent performance of PTB/LIG to NADH sensing, hydroxybutyrate dehydrogenase was immobilised via encapsulation with chitosan and polyvinyl butyral (PVB) which was used for HB biosensing over the linear range of 0.5 M to 1 mM with NAD+ dissolved in solution. In addition, the co-immobilisation of NAD+ and HBD on PTB/LIG was conducted by optimisation of enzyme and NAD+ amount per electrode, which shows excellent reproducibility and satisfactory HB biosensing performance. Further experiments to improve the long-term stability of the enzyme electrode is expected in the future. The proposed integrated electrode system also possesses the potential to extend to a multichannel sensor array for the detection of multiple biomarkers (e.g. pH and glucose) for diagnosis and management of DKA.
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Cruz, Hugo Cardoso da. "Development of electrodes in polymeric flexible substrates for organic biosensors." Master's thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/16270.
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Mestrado em Engenharia FísicaThe increase of organic electronics and consequently, the development of sensors based on organic polymers have attracted a lot of attention of the scientific community. Intrigued by these multifunctional, easily processed and low cost materials, it has started to develop odour biosensors for different applications, including medical field and the detection of various diseases. The present work, is focused in the scaling-up of a devoted laboratory approach, in particular concerning the development of organic odour biosensors (electronic nose concept) based on a conductive polymer (PEDOT:PSS) in a pre-industrial approach and produced by means of electronic printing techniques, such as screen printing and slot die. New carbon microelectrodes with different geometrical parameters were designed and processed by the screen printing technique. Further, the slot die technique was applied in order to print the PEDOT:PSS film over the microelectrodes. After the fabrication process, the sensors were morphologically characterized by optical microscopy, atomic force microscopy, profilometry and electrically identified by the two points probe method. The sensors were tested with the use of different analytes with the main focus on two gynaecological analytes. The resistive and capacitive electrical sensor responses for the analytes were analysed and discussed in depth. Important results were obtained with regard to the influence of the geometrical parameters of the carbon microelectrodes and also to the polymer thickness. Finally, the tests on the sensors were also carried out with the use of other analytes which contained blue cheese.
O desenvolvimento de eletrónica orgânica e consequentemente o desenvolvimento de sensores baseados em polímeros orgânicos, atraíram a atenção da comunidade científica. Motivada pela multifuncionalidade, fácil processamento e baixo custo destes materiais, novos biossensores de odor para diversas aplicações começaram a ser desenvolvidos, incluindo na área médica, para a deteção de doenças. Este trabalho, baseou-se no processo de “scaling-up” de um trabalho prévio que teve um objetivo meramente laboratorial, em particular no desenvolvimento de biossensores orgânicos de odor (conceito de nariz eletrónico), baseados em polímeros orgânicos (PEDOT:PSS) num paradigma pré industrial e fabricados pelo meio de técnicas de impressão de eletrónica orgânica, tais como screen printing e slot die. Foram desenhados novos microelétrodos de carbono com diferentes parâmetros geométricos que foram posteriormente produzidos por screen printing. Através da técnica de impressa de slot die, foram posteriormente impresso filmes de PEDOT:PSS sobre os microelétrodos. Após o processo de fabrico, os sensores foram morfologicamente caraterizados por microscopia ótica, microscopia de força atómica, perfilometria e eletricamente caraterizados através da técnica de duas pontas. Os sensores foram testados para diferentes analitos, nomeadamente para dois analitos ginecológicos. A resposta resistiva e capacitiva dos sensores expostos aos analitos, foi obtida e analisada, com especial atenção na influência dos parâmetros geométricos dos microelétrodos de carbono e também na espessura do polímero. Por fim, os sensores foram também testados para outros analitos compostos por queijo azul.
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Joshi, Saumya [Verfasser], Paolo [Akademischer Betreuer] Lugli, Oliver [Gutachter] Hayden, and Paolo [Gutachter] Lugli. "Flexible biosensors using solution processable devices / Saumya Joshi ; Gutachter: Oliver Hayden, Paolo Lugli ; Betreuer: Paolo Lugli." München : Universitätsbibliothek der TU München, 2019. http://d-nb.info/1201481619/34.
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Chang, Yun-Tzu, and 張云慈. "A Flexible Direct-Growth CNT Biosensor." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/36164156537148135984.
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碩士國立清華大學
材料科學工程學系
101
In this study, a biosensor was fabricated by growing carbon nanotubes (CNTs) directly on polyimide flexible substrate at low temperatures (400 °C) with chemical vapor deposition (CVD) process. Thereafter, a biocompatible polymer (parylene) was coated on the surface area without CNTs as an insulator for future applications in flexible biosensors for in-vivo sensing. The surface of CNTs was modified with functional groups by utilizing UV-ozone, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), and N-hydroxysuccinimide (NHS) treatment to improve the biocompatibility for the following conjugation of protein. Following that, the sensing surface was modified with anti-human serum albumin (AHSA), blocked by bovine serum albumin (BSA), and then conjugated with different concentrations of targeted human serum albumin (HSA) for HSA detection. The electrical properties of the biosensors, applied with various HSA concentrations, were measured and quantified by using an electrochemical impedance spectroscopy (EIS) system under AC conditions. Results showed that the impedance change was well correlated to the HSA concentration from 2 * 10^-12 to 2 * 10^-1 mg/ml, and exhibited a detection limit of the 3 * 10^-11 mg/ml. In summary, the feasibility of the CNTs flexible biosensor for HSA detection was demonstrated by utilizing electrochemical impedimetry to quantify human serum albumin concentration. Compared to other CNTs flexible biosensors, because of the employment of CVD process and the 3D structure of the direct-growth CNTs, the biosensor proposed in this work could be fabricated by a simpler process and provide a good detection limit. It shows a great potential for future application of wearable biosensor and implanting detection.
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Hsu, FangTzu, and 許芳慈. "The study of flexible electric material for pesticide detection biosensor." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/04108894866057028158.
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碩士中華醫事科技大學
生物醫學研究所
99
The separative structure of an extended-gate field effect transistor (EGFET) is an extremely broad application for detecting ion content in a solution. Inflexible or brittle materials, such as glass, are commonly used as substrates for electrode fabrication. However, such materials limit the range for successful and cost effective application in the environment. In our research, indium tin oxide (ITO) films were directly deposited onto the polyethylenetelephthalate (PET) substrate as a working electrode for an EGFET. The component exhibited some advantages for pH sensors such as being small, bulk, low cost and material flexibility. The sensor facilitates package to biosensor of detecting pesticides. In the future, the proposed application will be able to detect pollutants rapidly. The initial experimental result showed this structure having the linear and pH Nerstern response of approximately 54-58 mV/pH between pH2 and pH12. In this study, The EnFET structure was immobilized acetylcholinesterase (AChE) resulting from a cross-link method. Normally, AchE hydrolyses acetylcholine (Ach). However these reactions were the result of hydrogen ion generation, causing the changed pH in the membrane. This allowed using the potentionmetric method for voltage value measurement. We changed the buffer pH, acetylcholine concentration and acetylcholinesterase concentration of this process. Result shows the optimization responses of the sensing for detection pesticides. Acetylcholinesterase has been used in the design of biosensors for the detection of pesticides, based on the inhibitor for AchE. This inhibition effect can decrease the hydrogen ions in the sensing membrane. In addition, the mechanisms can be a pesticide biosensor for detecting pollutants. Our experiential results shows that the EnFET is a detection method for 1 ppm Carbofuran pesticide sensing.
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AKANKSHA. "DEVELOPMENT OF NANOMATERIAL MODIFIED FLEXIBLE BIOSENSOR TOWARDS POINT OF CARE DIAGNOSTICS." Thesis, 2018. http://dspace.dtu.ac.in:8080/jspui/handle/repository/16233.
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We report results of the studies related to the fabrication of a novel, flexible, label-free, low-cost transducer platform comprising of Molybdenum disulfide, a transition metal dichalcogenide hydrothermally synthesized on a Whatman-1 filter paper. The obtained conducting paper has been employed for the detection and monitoring of HER-2, a widely used breast cancer biomarker. Monoclonal anti-HER-2 antibodies are immobilized via physisorption on the surface of the obtained transducer platform and BSA is then used to block the non-specific active sites, thereby producing the BSA/Anti-HER-2/MoS2/Cellulose immunoelectrode. The structural and morphological characteristics of the fabricated composites have been studied via XRD (X-ray diffraction), FT-IR (Fourier transform infrared spectroscopy) and FESEM (Field emission scanning electron microscopy) and AFM (Atomic force microscopy) studies. Further elemental and nd electrochemical studies have been performed using UV visible spectroscopy, XPS (X-ray photoelectron spectroscopy) and Chronoamperometry studies. The electrochemical sensing studies performed on the BSA/Anti-HER2/MoS2/Paper immunoelectrode revealed that the proposed biosensor can detect HER-2 over a wide linear range (0.1-500 ng ml-1), with an appreciable sensitivity of 78 μA ml ng-1 cm-2 and a lower detection limit of 0.07 ng ml-1. Hence, this paper based biosensor is a promising alternative to conventional medical diagnostics of breast cancer due to combined advantages of the cellulose substrate such as being eco-friendly, biodegradable, low cost, flexible, foldable, lightweight and having a shorter fabrication time. Thus, our proposed biosensor offers exciting opportunities for future Point-of Care diagnosis and monitoring of breast cancer development.
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KAO, CHAO-CHIEN, and 高肇乾. "Fabrication and Application of Liquid Crystal Biosensor on PDMS Flexible Substrate." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/zz375h.
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碩士國立聯合大學
光電工程學系碩士班
105
In this study, we propose liquid crystal (LC)-based biosensor for detecting protein and glutaraldehyde solution, respectively. The basic principle is based on strong specifically between the sensing material and target molecules. As the reaction occurs, LC molecule orientation is changed. Due to birefringent property of LCs, the orientation transition is studied by means of observing their optical texture of LCs using a polarizing optical microscope (POM). In order to quantify the property of optical texture, the Matlab software is applied to analyze the changes of optical texture. Besides, owing to PDMS material possess high transparency and flexibility, we present a LC biosensor based on the PDMS substrate with square micro wells. To investigate the concentration of glutaraldehyde solution, amine group was be self-assembled on the surface of PDMS substrate to detect the presence of glutaraldehyde solution. We can study the variation of optical property induced by the reorientation of LC molecules by means of POM observation. We also investigate the relationship between glutaraldehyde concentration and the optical characteristics of LC sensor by measuring the transmittance.
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Liu, Chun-hung, and 劉俊宏. "Investigation of Titanium Dioxide Electrochromic Material Applied to Flexible Miniaturized Biosensor." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/37407928847873442893.
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碩士國立雲林科技大學
光學電子工程研究所
99
In this thesis, the electrochromic titanium dioxide (TiO2) thin film was deposited on the flexible indium tin oxide polyethylene terephthalate (ITO PET) substrate by screen-printed technology. And the manufacturing conditions (distance between screen and substrate, TiO2 paste components) were modified to optimize the electrochromic property of the TiO2 thin film. As well as, the characteristics of the TiO2 thin films with different manufacturing conditions were analyzed by using X-ray diffractometer (XRD), ultraviolet-visible (UV-Vis) spectroscopy and cyclic voltammetric (CV) measurement system. Furthermore, the TiO2 thin film can be applied to measure hydrogen (H+) ion or sodium (Na+) ion concentration in electrolyte by optical detection and electrochemical detection. For optical detection, the electrochromic property of the TiO2 thin films was obtained in H+ ion or Na+ ion electrolytes, and the transmittances (T%) of the TiO2 thin film was corresponding with H+ ion or Na+ ion concentration in electrolytes. Therefore, the H+ ion or Na+ ion concentration in electrolytes can be obtained by measuring the transmittance of the TiO2 thin film. Furthermore, the redox reaction of the TiO2 thin film was measured by cyclic voltammetric measurement system. The reduction potential of the TiO2 thin film was related with H+ ion or Na+ ion concentration in electrolytes, Therefore, the H+ ion or Na+ ion concentration in electrolytes can also be obtained by electrochemical detection. In this thesis, the TiO2 thin film prepared on ITO PET substrate was applied to optical sensor, and the H+ ion sensitivity and linearity of the TiO2 thin film are 1.125 T%/pH and 0.9934, respectively, as well as, the Na+ ion sensitivity and linearity of the TiO2 thin film are 2.242 T%/pNa and 0.9979, respectively. For the electrochemical detection, the H+ ion sensitivity and linearity of the TiO2 thin film are 0.3655 (mA/cm2)/pH and 0.9814, respectively, and the Na+ ion sensitivity and linearity of the TiO2 thin film are 0.090 (mA/cm2)/pNa and 0.9556, respectively. According to the above experimental results, the electrochromic TiO2 thin film can be applied to multi-ions sensor with multi-detection method, which can provide more accurate for H+ ion or Na+ ion sensing than pure optical detection or electrochemical detection.
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Chen, Yu-Liang, and 陳昱良. "Au Nanostructures on Flexible Substrate: Fabrication and Applications in Biosensor and Supercapacito." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/99674687789499474579.
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博士國立交通大學
應用化學系碩博士班
102
In this thesis, we studied fabrication of Au nanostructures on flexible substrate and its applications in biosensor and supercapacitor. A facile fabrication of high density Au nanostructures including nanothorns (NTs), nanocorals (NCs), nanoslices (NSs), and nanowires (NWs) which were electrochemically grown on flexible plastic substrates of polyethylene terephthalate (PET). By adjusting the electroplating conditions, we proposed a growth mechanism of Au nanostructures. Among them, the specific real surface area (RSA) of the Au NWs is the highest one (26100 cm2/g). This is due to the high aspect ratio of the one-dimensional NW structure. Further, as-fabricated Au nanostructures on flexible substrate were employed and used as electrode in biosensor and supercapacitor applications. For biosensor application, a thrombin-binding aptamer was immobilized on the surfaces of the Au nanostructures to form highly sensitive electrochemical impedance spectroscopic (EIS) as biosensors for thrombin recognition. The binding of thrombin to the aptamer was monitored by EIS in the presence of [Fe(CN)6]3-/4-(aq). The protein (1 – 50 pM) was detected linearly by the Au nanostructures. Among them, the Au NWs exhibited excellent thrombin detection performances (1130 pM-1 cm-2). The biosensor provided high sensitivity, selectivity, and stability due to its high surface area. For supercapacitor application, electrodes composed of ultrathin MnO2 (thickness 5 - 80 nm) spines on Au NW stems (length 10 - 20 μm, diameter 20 - 100 nm) were electrochemically grown on flexible PET substrates. The electrodes demonstrated high specific capacitance, high specific energy value, high specific power value, and long-term stability. In Na2SO4(aq) (1 M), the maximum specific capacitance was determined to be 1130 F/g by cyclic voltammetry (CV, scan rate 2 mV/s) using a three-electrode system. From a galvanostatic (GV) charge/discharge test using a two-electrode system, a maximum capacitance 225 F/g (current density 1 A/g) was measured. Even at a high charge/discharge rate 50 A/g, the specific capacitance remained at an extremely high value 165 F/g. The flexible electrodes also exhibited a maximum specific energy 15 Wh/kg and a specific power 20 kW/kg at 50 A/g. After five thousand cycles at 10 A/g, 90% of the original capacitance was retained. A highly flexible solid-state device was also fabricated to reveal its supercapacitance performance.
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Chen, Chien-cheng, and 陳建呈. "Development of Flexible, Miniaturized and Multi-functional Biosensor with Remote Surveillance System." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/59998337184026151123.
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博士國立雲林科技大學
工程科技研究所博士班
100
A flexible, miniaturized, and multi-functional biosensor based on flexible array sensor and a remote monitor system based on wireless sensor network (WSN) were presented in this dissertation. The main part of the flexible array sensor was fabricated by screen printed method, and the ruthenium dioxide (RuO2) thin film on each sensing window of the array sensor was deposited by radio frequency (R.F.) sputtering method. Moreover, a flexible miniaturized reference electrode fabricated by electrodepositing conductive polymer material on flexible substrate was also presented. As well as, the analytic data fusion methods consisting of the average and weighted data fusion were used to estimate the measurement data of the flexible array sensors. In addition, a wireless sensor network platform for flexible array sensor has been developed. The WSM platform was used for dynamic measurement of voltage-time (V-T) and real-time display. In accordance with experimental results, the pH, pCa, pNa values estimated by weighted data fusion method are accurate than that estimated by average data fusion method. Furthermore, that the flexible array sensors is actually used to detect the pH, pCa, pNa values of different commercial drinks was also investigated. Additionally, the measurement data were transmitted to remote personal computer through WSN, which can store and analyze the measurement data. Besides, the sensing system provides some characteristic analyses such as sensitivity and linearity in this dissertation.
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Ye, Guan-Chen, and 葉冠辰. "Integrated Differential Reference Electrode in the Arrayed Flexible Biosensor Based on Microfluidic Framework." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/86900585301787295710.
Full textAbstract:
碩士國立雲林科技大學
電子與光電工程研究所碩士班
100
In this thesis, the ruthenium oxide (RuO2) sensing film was fabricated by sputtering system and the differential reference electrode was fabricated by screen-printed technology for integrating RuO2 thin film as arrayed flexible biosensor. Arrayed flexible biosensor was integrated to the poly-dimethylsiloxane (PDMS) microchannel as the microfluidic device for observing electrochemical characterization of the sensing films in dynamic conditions. In this thesis, the average sensitivity and linearity of arrayed flexible pH sensor was 53.68 mV/pH and 0.978, respectively. In the dynamical conditions, the best flow rate of arrayed flexible pH sensor was 10 μl / min, and the average sensitivity and linearity of arrayed flexible pH sensor were 57.18 mV/pH and 0.989, respectively. Furthermore, we prepare glucose sensing membrane and drop on sensing windows of arrayed flexible pH sensor as arrayed flexible glucose sensor. The sensitivity and linearity of arrayed flexible glucose sensor was 0.33 mV(mg/dL)-1 and 0.972, respectively. In the dynamical conditions, the best flow rate of arrayed flexible pH sensor is 15 μl / min, and the average sensitivity and linearity of arrayed flexible glucose sensor were 0.95 mV(mg/dL)-1 and 0.997, respectively. According to described above result, we also prepare chlorine ion selective membrane and drop on sensing windows of arrayed flexible pH sensor as arrayed flexible chlorine ion sensor. The average sensitivity and linearity of arrayed flexible chlorine ion sensor was 49.76 mV/pCl and 0.986, respectively. In the dynamical conditions, the best flow rate of arrayed flexible pH sensor is 15 μl / min, and the average sensitivity and linearity of arrayed flexible chlorine ion sensor were 51.91 mV/pCl and 0.994, respectively. The experimental result demonstrates that arrayed flexible biosensor in this thesis can be applied to detect the fluidic concentration and applied to the fabrication of other biosensors. Furthermore, the electrochemical impedance spectroscopy (EIS) was used to measure electron transfer between electrolyte solution and biosensor. The measurement results show that the potassium hexacyanoferrate can increase electron transfer rate in reaction process, and the optimum amount of potassium hexacyanoferrate for arrayed flexible biosensor was 1 M. And the charge transfer resistance of sensing membrane for arrayed flexible biosensor was decreased with rising concentration of solutions.
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Cheng, Tsung-Yi, and 程聰義. "Integrated Differential Reference Electrode in the Arrayed Flexible Glucose Biosensor Based on Microfluidic Framework." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/60270655206793057314.
Full textAbstract:
碩士國立雲林科技大學
電子與光電工程研究所碩士班
101
In this thesis, the ruthenium dioxide (RuO2) sensing membrane was deposited on polyethylene terephthalate (PET) substrate by radio frequency (RF) sputtering system. The screen-printer technology was employed to fabricate the conductive wires of RuO2 thin membranes and protected the conductive wires as package. And the differential reference electrode was integrated in the arrayed flexible biosensor that was completed. The microfluidic device was formed by combining the arrayed flexible biosensor and microchannel, which was used to investigate the electrochemical characteristics of the sensing membrane at dynamic conditions. In this thesis, the differential reference electrode had good stability characteristics, which sensitivity and ratio of voltage change were 0.156 mV/pH and 0.26%, respectively. The sensitivity and linearity of the arrayed flexible pH biosensor based on differential reference electrode were 58.31 mV/pH and 0.981, respectively. At dynamic conditions, the best flow rate was 20 μL/min, in this flow rate, the sensitivity and linearity were 66.73 mV/pH and 0.993, respectively. The arrayed flexible glucose biosensor was completed by using glucose oxidase (GOx) to modify the ruthenium dioxide (RuO2) sensing membrane. The sensitivity and linearity of the arrayed flexible glucose biosensor were 11.84 mV(100 mg/dL)-1 and 0.995, respectively. At dynamic conditions, the best flow rate was 25 μL/min, in this flow rate, the sensitivity and linearity were 31.35 mV(100 mg/dL)-1 and 0.980, respectively. In addition, the electrochemical impedance spectroscopy (EIS) was used to investigate that the whether the RuO2 sensing membrane was successfully modified by GOx, and studied the characteristics of transmission between biosensor and electrolyte. The experimental results showed that the GOx was successfully modified on RuO2 sensing membrane. The charge transfer resistance of the Nafion/GOx/RuO2 was increased significantly, and the charge transfer resistance decreased with increasing glucose concentration.
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Afentakis, Themistokles. "Solid state thin film transistor electronics & applications to flexible displays & large area biosensor arrays /." Diss., 2004. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3154551.
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Lin, Jyun-Wun, and 林俊文. "Integration and Fabrication of the Flexible Arrayed Glucose Biosensor Based on Magnetic Beads and Microfluidic Framework." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/96498101962508912940.
Full textAbstract:
碩士國立雲林科技大學
電子工程系
102
In this thesis, the flexible arrayed biosensor was prepared. The ruthenium dioxide (RuO2) was used and deposited on the polyethylene terephthalate (PET) substrate by the radio frequency (RF) sputtering system. The conducting wires (Silver paste) and the insulation layer (Epoxy) were prepared by screen printer technology, respectively. And the differential reference electrode was fabricated and completed the process of the arrayed flexible arrayed biosensor. In order to analyze the electrochemical characteristics under the dynamical condition, the microfluidic device was also used and combined with flexible arrayed biosensor. In this thesis, the sensitivity, linearity and stability of the flexible arrayed pH sensor were analyzed, respectively. According to the experimental results, the flexible arrayed pH sensor had better stability. Under the static conditions, the sensitivity and linearity of the flexible arrayed pH sensor were 52.402 mV/pH and 0.977, respectively. Under the dynamical conditions, the sensitivity and linearity of the flexible arrayed pH sensor were 68.589 mV/pH and 0.995, respectively. The arrayed flexible glucose biosensor was completed by using magnetic beads and glucose oxidase (GOx) to modify the working electrode. The electrochemical impedance spectroscopy was used and investigate that the whether the working electrodes were successfully modified by GOx and magnetic beads. The sensitivity, linearity and stability of the flexible arrayed glucose biosensor combined with magnetic beads were analyzed, respectively. According to the experimental results, the flexible arrayed glucose biosensor combined with magnetic beads had better stability. Under the static conditions, the sensitivity and linearity of the flexible arrayed glucose biosensor combined with magnetic beads were 8.350 mV/mM and 0.985, respectively. Under the dynamical conditions, the sensitivity and linearity of the flexible arrayed glucose biosensor combined with magnetic beads were 11.858 mV/ mM and 0.995, respectively.
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Huang, Yen Hsiang, and 黃彥翔. "Development of Zn1-xInxOy sensing membrane on flexible substrate using sol-gel synthesis for biosensor applications." Thesis, 2019. http://ndltd.ncl.edu.tw/cgi-bin/gs32/gsweb.cgi/login?o=dnclcdr&s=id=%22107CGU05428002%22.&searchmode=basic.
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(10716684), Bongjoong Kim. "ADDITIVE MANUFACTURING TECHNOLOGIES FOR FLEXIBLE OPTICAL AND BIOMEDICAL SYSTEMS." Thesis, 2021.
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Advances in additive manufacturing technologies enable the rapid, high-throughput generation of mechanically soft microelectromechanical devices with tailored designs for many applications spanning from optical to biomedical applications. These devices can be softly interfaced with biological tissues and mechanically fragile systems, which enables to open up a whole new range of applications. However, the scalable production of these devices faces a significant challenge due to the complexity of the microfabrication process and the intolerable thermal, chemical, and mechanical conditions of their flexible polymeric substrates. To overcome these limitations, I have developed a set of advanced additive manufacturing technologies enabling (1) mechanics-driven manufacturing of quasi-three-dimensional (quasi-3D) nanoarchitectures with arbitrary substrate materials and structures; (2) repetitive replication of quasi-3D nanoarchitectures for infrared (IR) bandpass filtering; (3) electrochemical reaction-driven delamination of thin-film electronics over wafer-scale; (4) rapid custom printing of soft poroelastic materials for biomedical applications.
First, I have developed a new mechanics-driven nanomanufacturing method enabling large-scale production of quasi-3D plasmonic nanoarchitectures that are capable of controlling light at nanoscale length. This method aims to eliminate the need for repetitive uses of conventional nanolithography techniques that are time- and cost-consuming. This approach is innovative and impactful because, unlike any of the conventional manufacturing methods, the entire process requires no chemical, thermal, and mechanical treatments, enabling a large extension of types of receiver substrate to nearly arbitrary materials and structures. Pilot deterministic assembly of quasi-3D plasmonic nanoarrays with imaging sensors yields the most important advances, leading to improvements in a broad range of imaging systems. Comprehensive experimental and computational studies were performed to understand the underlying mechanism of this new manufacturing technique and thereby provide a generalizable technical guideline to the manufacturing society. The constituent quasi-3D nanoarchitectures achieved by this manufacturing technology can broaden considerations further downscaled plasmonic metamaterials suggest directions for future research.
Second, I have developed mechanics-driven nanomanufacturing that provides the capability to repetitively replicate quasi-3D plasmonic nanoarchitectures even with the presence of an extremely brittle infrared-transparent spacer, such as SU-8, thereby manipulating IR light (e.g., selectively transmitting a portion of the IR spectrum while rejecting all other wavelengths). Comprehensive experimental and computational studies were performed to understand the underlying nanomanufacturing mechanism of quasi-3D plasmonic nanoarchitectures. The spectral features such as the shape of the transmission spectrum, peak transmission and full width at half maximum (FWHM), etc. were studied to demonstrate the bandpass filtering effect of the assembled quasi-3D plasmonic nanoarchitecture.
Third, I have developed an electrochemical reaction-driven transfer printing method enabling a one-step debonding of large-scale thin-film devices. Conventional transfer printing methods have critical limitations associated with an efficient and intact separation process for flexible 3D plasmonic nanoarchitectures or bio-integrated electronics at a large scale. The one-step electrochemical reaction-driven method provides rapid delamination of large-scale quasi-3D plasmonic nanoarchitectures or bio-integrated electronics within a few minutes without any physical contact, enabling transfer onto the target substrate without any defects and damages. This manufacturing technology enables the rapid construction of quasi-3D plasmonic nanoarchitectures and bio-integrated electronics at a large scale, providing a new generation of numerous state-of-art optical and electronic systems.
Lastly, I have developed a new printing method enabling the direct ink writing (DIW) of multidimensional functional materials in an arbitrary shape and size to rapidly prototype stretchable biosensors with tailored designs to meet the requirement of adapting the geometric nonlinearity of a specific biological site in the human body. Herein, we report a new class of a poroelastic silicone composite that is exceptionally soft and insensitive to mechanical strain without generating significant hysteresis, which yields a robust integration with living tissues, thereby enabling both a high-fidelity recording of spatiotemporal electrophysiological activity and real-time ultrasound imaging for visual feedback. Comprehensive in vitro, ex vivo, and in vivo studies provide not only to understand the structure-property-performance relationships of the biosensor but also to evaluate infarct features in a murine acute myocardial infarction model. These features show a potential clinical utility in the simultaneous intraoperative recording and imaging on the epicardial surface, which may guide a definitive surgical treatment.
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"Flexible Electronics and Display Technology for Medical, Biological, and Life Science Applications." Doctoral diss., 2014. http://hdl.handle.net/2286/R.I.25926.
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abstract: This work explores how flexible electronics and display technology can be applied to develop new biomedical devices for medical, biological, and life science applications. It demonstrates how new biomedical devices can be manufactured by only modifying or personalizing the upper layers of a conventional thin film transistor (TFT) display process. This personalization was applied first to develop and demonstrate the world's largest flexible digital x-ray detector for medical and industrial imaging, and the world's first flexible ISFET pH biosensor using TFT technology. These new, flexible, digital x-ray detectors are more durable than conventional glass substrate x-ray detectors, and also can conform to the surface of the object being imaged. The new flexible ISFET pH biosensors are >10X less expensive to manufacture than comparable CMOS-based ISFETs and provide a sensing area that is orders of magnitude larger than CMOS-based ISFETs. This allows for easier integration with area intensive chemical and biological recognition material as well as allow for a larger number of unique recognition sites for low cost multiple disease and pathogen detection.
The flexible x-ray detector technology was then extended to demonstrate the viability of a new technique to seamlessly combine multiple smaller flexible x-ray detectors into a single very large, ultimately human sized, composite x-ray detector for new medical imaging applications such as single-exposure, low-dose, full-body digital radiography. Also explored, is a new approach to increase the sensitivity of digital x-ray detectors by selectively disabling rows in the active matrix array that are not part of the imaged region. It was then shown how high-resolution, flexible, organic light-emitting diode display (OLED) technology can be used to selectively stimulate and/or silence small groups of neurons on the cortical surface or within the deep brain as a potential new tool to diagnose and treat, as well as understand, neurological diseases and conditions. This work also explored the viability of a new miniaturized high sensitivity fluorescence measurement-based lab-on-a-chip optical biosensor using OLED display and a-Si:H PiN photodiode active matrix array technology for point-of-care diagnosis of multiple disease or pathogen biomarkers in a low cost disposable configuration.Dissertation/Thesis
Doctoral Dissertation Electrical Engineering 2014
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Lin, Chin-Yi, and 林欽益. "Design and Implementation of Data Fusion Measurement System Based on LabVIEW Used for Flexible Arrayed pH Sensor and Glucose Biosensor." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/15258575408066207321.
Full textAbstract:
碩士國立雲林科技大學
電子工程系
102
In this thesis, the data fusion measurement system was designed and implemented by LabVIEW, which could use for flexible arrayed pH sensor and glucose biosensor. The ruthenium dioxide (RuO2) sensing membrane was deposited on polyethylene terephthalate (PET) substrate by radio frequency sputtering system, and then the screen-printer technology was employed to fabricate the differential reference electrode, conductive wires and insulation layer. The analyzed methods were about sensitivity, linearity, drift effect and hysteresis effect that were measured on the flexible arrayed sensor via voltage-time (V-T) measurement system. The average sensitivity and linearity were 55.32 mV/pH and 0.979, respectively. The sensitivities after computing the measurement results of the flexible arrayed pH sensor in the average data fusion method (ADF), self-adaptive data fusion method (SADF) and coefficient of variance data fusion method (CVDF) were increased to 55.42 mV/pH, 55.89 mV/pH, and 57.33 mV/pH, respectively. The nafion was applied as immobilization material due to it had high chemical stability and best biocompatibility. Therefore, the nafion was used to fix glucose oxidase (GOD) on RuO2 sensing membrane of flexible arrayed glucose biosensor. In the concentration ranging from 100 mg/dL to 500 mg/dL of glucose solution, the average sensitivity and linearity were 0.241 mV/(mg/dL) and 0.996, respectively. The sensitivities after computing in the ADF, SADF, and CVDF were 0.241 mV/(mg/dL), 0.241 mV/(mg/dL) and 0.244 mV/(mg/dL), respectively.
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Chen, Jie-Ting, and 陳玠廷. "Design and Analysis of Flexible Screen-Printed Arrayed Glucose Biosensor Based on Multifunction Real-Time Remote Home Care in Wireless Sensing System." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/62050474617467732601.
Full textAbstract:
碩士國立雲林科技大學
電子與光電工程研究所碩士班
102
In this thesis, the wireless sensor network (WSN) with Zigbee technique is integrated with the glucose biosensor. The wireless sensing system is accomplished by the graphical language laboratory virtual instrumentation engineering workbench (LabVIEW). The wireless sensing system can be classified into two parts, which are the glucose detection system of front end and transmission platform of back end. The glucose detection system embraces ruthenium dioxide polyethylene terephthalate (RuO2/PET) biosensor, silver/silver chloride (Ag/AgCl) reference electrode and readout circuit device. The transmission platform is transmitted the detection signals in real-time, which displays the measurement results in the computer. In addition, the wireless sensing system is used to detect pH value in different buffer solutions and glucose value in different concentrations of glucose solutions. The Nafion is applied as immobilization material due to it has high chemical stability and the best biocompatibility. The enzyme composite solution is dropped on the RuO2 film as a glucose biosensor. We provide a real-time monitoring and rapid detection wireless sensing system. The range of pH values from pH 1 to pH 13 has good average sensitivity 51.38 mV/pH and linearity 0.995. The range of glucose solution concentration from 100 mg/dL to 500 mg/dL has good average sensitivity 0.179 mV(mg/dL)-1 and linearity 0.999 of the glucose biosensor.
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YAN, SIAO-JIE, and 嚴孝傑. "The Analysis of the Stability, Interference, and Impedance for Magnetic Beads and Graphene Modified in Arrayed Flexible Nickel Oxide Glucose and Lactate Biosensor Based on Microfluidic Framework and the Measurement of Real-Time Sensing System." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/694838.
Full textAbstract:
碩士國立雲林科技大學
電子工程系
105
In this thesis, nickel oxide (NiO) was applied to a flexible arrayed pH sensor, and its sensitivity could be enhanced by changing oxygen content of sputtering gas. The optimal NiO film was applied to a flexible arrayed lactate biosensor and a flexible arrayed glucose biosensor. After that, lactate dehydrogenase (LDH) and glucose oxidase (GOD) were immobilized on the NiO film of above structure to fabricate the flexible arrayed lactate biosensor and flexible arrayed glucose biosensor, respectively. We used graphene oxide (GO) and magnetic beads (MBs) to modify the sensing film, which could enhance the ability of enzyme adsorption and the characteristics of the biosensors. Moreover, the electrochemical impedance spectroscopy was used to analyze the electrochemical impedance and confirm whether GO and MB did successfully modify the sensing film. Subsequently, it was investigated the response time, decay rate, interference effect and detection limit of the lactate and glucose biosensors based on NiO film modified by GO and MBs, respectively. In addition, the lactate and glucose biosensors based on NiO film modified by GO and MBs were integrated in the microfluidic framework, which sensing characteristics were respectively researched under different flow rates. Finally, the lactate and glucose biosensors based on NiO film modified by GO and MBs were combined in the wireless real-time sensing system based on XBee module to realize remote monitoring.
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Chen, Ruei-Ting, and 陳睿廷. "Integrating the Fabrication of the Differential Reference Electrode and Graphene Modified in Arrayed Flexible Glucose Biosensor System Based on Magnetic Beads and Microfluidic Framework as well as the Measurement and Impedance Analysis of the System." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/02042610160721218923.
Full textAbstract:
碩士國立雲林科技大學
電子工程系
103
In this thesis, the arrayed flexible pH sensor and glucose biosensor were proposed. The ruthenium dioxide (RuO2) sensing films were deposited by radio frequency (r.f.) sputtering system and the screen-printed technique was used to construct the silver conducting wires and insulation layer of the arrayed flexible RuO2 electrodes. The RuO2 electrode was employed as pH sensor to measure different pH solutions and the sensitivity and linearity of pH sensor were 52.280 mV/pH and 0.998, respectively. The glucose biosensor was prepared through using magnetic beads (MB) and graphene (GR) to modify glucose oxidase (GOx) and dropping on the RuO2 electrode. The electrochemical impedance spectra (EIS) was used to investigate the capability of electron transfer of the different electrodes and demonstrate whether the biosensors had already been completely modified by MB and GR through the different resistances of the biosensors. The average sensitivity and linearity of RuO2/Graphene/Magnetic Bead-GOx-Nafion glucose biosensor were 10.628 mV/mM and 0.998, respectively. Furthermore, the glucose biosensor had superior stability. The RuO2/Graphene/Magnetic Bead-GOx-Nafion glucose biosensor only had relative standard deviation of 1.209% for ten repetitive measurements and still had relative sensitivity of 82.2 % after 28 days. In order to enhance performance of the pH sensor and glucose biosensor, the microfluidic device had been utilized and developed. In the measurement processes, the different pH and glucose solutions were investigated in various flow rates. According to the experimental results, the sensitivity of the arrayed flexible pH sensor was enhanced from 52.280 mV/pH to 57.981 mV/pH and the sensitivity of the RuO2/Graphene/Magnetic Bead-GOx-Nafion arrayed flexible glucose biosensor was enhanced from 10.628 mV/mM to 13.541 mV/mM. This phenomenon was resulted from promotion of the catalyzed reaction and decline of the diffusion resistance. In order to carry out the wireless sensing measurements, the wireless sensing system which complied the ZigBee standard was employed to transmit the signals of the pH or glucose measurements in this thesis, and the system consisted of the XBee device, Arduino Mega 2560, readout circuit, arrayed flexible pH or glucose biosensor and computer. According to the experimental results, the average sensitivity and linearity of the arrayed flexible pH sensor were 51.063 mV/pH and 0.988, respectively, and the average sensitivity and linearity of the RuO2/Graphene/Magnetic Bead-GOx-Nafion glucose biosensor were 11.005 mV/mM and 0.995, respectively.
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(6863093), Li-Kai Lin. "Pollutant and Inflammation marker detection using low-cost and portable microfluidic platform, and flexible microelectronic platform." Thesis, 2019.
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Existing methods for pathogen/pollutant detection or wound infection monitoring employ high-cost instruments that could only be operated by trained personnel, and costly device-based detection requires a time-consuming field-to-lab process. This expensive process with multiple prerequisites prolongs the time that patients must wait for a diagnosis. Therefore, improved methods for point-of-care biosensing are necessary. In this study, we aimed to develop a direct, easy-to-use, portable, low cost, highly sensitive and selective sensor platform with the goal of pollutant detection and wound infection/cancer migration monitoring. This study has two main parts, including microfluidic, electrical, and optical sensing platforms. The first part, including chapters 2, 3, and 4, focuses on Bisphenol A (BPA) lateral flow assay (LFA) detection; the second part, including chapter 5 focuses on the electrical sensing platform fabrication for one of the markers of inflammation, matrix metalloproteinases-9 (MMP-9), monitoring/detection. In chapters 2, 3, and 4, we found that the few lateral flow assays (LFAs) established for detecting the endocrine-disrupting chemical BPA have employed citrate-stabilized gold nanoparticles (GNPs), which have inevitable limitations and instability issues. To address these limitations, in chapter 2, a more stable and more sensitive biosensor is developed by designing strategies for modifying the surfaces of GNPs with polyethylene glycol and then testing their effectiveness and sensitivity toward BPA in an LFA. In chapter 3, we describe the development of a new range-extended bisphenol A (BPA) detection method that uses a surface enhanced Raman scattering lateral flow assay (SERS-LFA) binary system. In chapter 4, we examine advanced bisphenol A (BPA) lateral flow assays (LFAs) that use multiple nanosystems. The assays include three nanosystems, namely, gold nanostars, gold nanocubes, and gold nanorods, which are rarely applied in LFAs, compared with general gold nanoparticles. The developed LFAs show different performances in the detection of BPA. In chapter 5, a stable electrical sensing platform is developed for MMP-9 detection.
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CHEN, JIAN-SYUN, and 陳建勳. "The Research of Integrating the Differential Reference Electrode as well as Magnetic Beads and Graphene Modified in Arrayed Flexible IGZO Glucose Biosensor Based on Microfluidic Framework and the Fabrication of Multifunctional Enzyme Real-Time Sensing System." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/wke9x5.
Full textAbstract:
碩士國立雲林科技大學
電子工程系
104
In this thesis, it was mentioned the enzymatic glucose biosensor was manufactured by using radio frequency sputtering system, thermal evaporation system and screen-printed technology, whose glucose sensing membrane was composed of indium gallium zinc oxide (IGZO) membrane and glucose oxidase (GOx). For enhancing sensing characteristics of enzymatic glucose biosensor, the sensing membrane was modified by graphene oxide (GO) and magnetic beads (MBs) to improve adsorption of enzyme and sensing characteristics. According to experiential results, the average sensitivity and linearity of enzymatic glucose biosensor modified by GO and MBs were 10.391 mV/mM and 0.998, respectively. To demonstrate that sensing membrane was successfully modified by GO and MBs, the electrochemical impedance spectroscopy (EIS) was used to analyze the capability of electron transfer for sensing membranes. The stability, lifetime, interference and detection limit of the enzymatic glucose biosensor modified by GO and MBs were investigated. Finally, the enzymatic glucose biosensor modified by GO and MBs was integrated with the microfluidic framework and the sensing characteristics under dynamic conditions, i.e., solution under flowing condition, were investigated. According to experiential results, under dynamic conditions, the average sensitivity and linearity of enzymatic glucose biosensor modified by GO and MBs were enhanced to 12.383 mV/mM and 0.999, respectively. Furthermore, in order to develop the real-time sensing system applied in measurement of pH value and multifunctional enzyme, the pH sensor as well as enzymatic glucose, lactate and urea biosensor modified by GO and MBs was combined with wireless sensing system to carry out the wireless sensing measurements, and this system complied with ZigBee wireless networking protocol which consisted of the XBee module, Arduino Mega 2560, readout circuit, biosensor and computer was employed to transmit the measurement signals. According to the experimental results, the average sensitivities of the pH sensor as well as enzymatic glucose, lactate and urea biosensor modified by GO and MBs were 50.059 mV/pH, 10.257 mV/mM, 55.747 mV/mM and 2.066 mV/(mg/dl), respectively.
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WU, CIAN-YI, and 吳芊嬑. "Investigation on Sensing Characteristics and Stability of Arrayed Flexible Glucose and Urea Biosensor Based on TiO2 and NiO Films Modified by Magnetic Beads and Graphene Oxide, and Integrated with Microfluidic Framework and Real-Time Sensing System." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/3v4kj4.
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碩士國立雲林科技大學
電子工程系
106
In this thesis, two kinds of metal oxide were proposed as martrix for flexible arrayed urea biosensor. The metal oxide films were Nickel Oxide (NiO) and Titanium dioxide (TiO2), respectively. The radio frequency sputtering system deposits the sensing film, and the screen printing technology were used to prepare the conductive arrayed wires and the reference electrode, and the epoxy is to encapsulate flexible arrayed urea biosensor. However, the covalent binding method is used to immobilize the enzyme between the matrix of the urea biosensor, and the preparation of the urea biosensors were completed. Afterwards, the sensing films of nickel oxide and titanium dioxide were modified by using graphene oxide and magnetic beads to improve its properties. The basically sensing properties of the two kinds of matrix biosensors were measured, and response time, interference and detection limit were also measured. However, the urea biosenosrs were integrated into the microfluidic measurement system and wireless real-time sensing system to measure the sensing properties of the urea biosensor under dynamic conditions, and it achieved remote monitoring. In addition, the feasibility of TiO2 matrix for the development of glucose sensors were discussed. Finally, we compared the literatures with the urea biosensors and glucose sensor in this thesis.
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"Biosensors and CMOS Interface Circuits." Master's thesis, 2014. http://hdl.handle.net/2286/R.I.24790.
Full textAbstract:
abstract: Analysing and measuring of biological or biochemical processes are of utmost importance for medical, biological and biotechnological applications. Point of care diagnostic system, composing of biosensors, have promising applications for providing cheap, accurate and portable diagnosis. Owing to these expanding medical applications and advances made by semiconductor industry biosensors have seen a tremendous growth in the past few decades. Also emergence of microfluidics and non-invasive biosensing applications are other marker propellers. Analyzing biological signals using transducers is difficult due to the challenges in interfacing an electronic system to the biological environment. Detection limit, detection time, dynamic range, specificity to the analyte, sensitivity and reliability of these devices are some of the challenges in developing and integrating these devices. Significant amount of research in the field of biosensors has been focused on improving the design, fabrication process and their integration with microfluidics to address these challenges. This work presents new techniques, design and systems to improve the interface between the electronic system and the biological environment. This dissertation uses CMOS circuit design to improve the reliability of these devices. Also this work addresses the challenges in designing the electronic system used for processing the output of the transducer, which converts biological signal into electronic signal.Dissertation/Thesis
M.S. Electrical Engineering 2014
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Wu, You-Xiang, and 吳友祥. "The Research of Differential Reference Electrode Integrated with Magnetic Beads and Graphene Oxide Modified Arrayed Flexible IGZO/Al Ascorbic Acid Biosensor Based on Microfluidic Framework as well as Measurements for Sensing Characteristics, Equivalent Circuit and Real-time Sensing System." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/ktdemv.
Full textAbstract:
碩士國立雲林科技大學
電子工程系
106
In this thesis, the screen-printed technology, radio frequency sputtering system and thermal evaporation system were used to integrate indium gallium zinc oxide (IGZO) membrane, Al electrode and silver paste onto the PET (polyethylene terephthalate) substrate. Next, the covalent bonding was used to immobilize ascorbate oxidase (AOX) onto the IGZO sensing membrane, and the flexible arrayed enzymatic L-ascorbic acid (L-AA) biosensor was completed. Besides, the graphene oxide (GO) and magnetic beads (MBs) were used to modify IGZO sensing membrane, and the electrochemical impedance spectroscopy (EIS) was used to confirm whether the GO and MBs were modified onto the sensing membrane successfully. According to the experimental results, the average sensitivity and linearity of MBs-AOX/GO/IGZO/Al L-AA biosensor were 78.9 mV/decade and 0.997, respectively. In this thesis, the response time, drift effect, hysteresis effect, anti-interfering effect and life time were investigated. Moreover, the sensing characteristic of L-AA biosensor which was integrated with microfluidic framework was detected under the different flow rates. Finally, in order to achieve remote monitoring, the L-AA biosensor was integrated with wireless real-time sensing system based on XBee module.
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(8647860), Aniket Pal. "Design and Fabrication of Soft Biosensors and Actuators." Thesis, 2020.
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Soft materials have gained increasing prominence in science and technology over the last few decades. This shift from traditional rigid materials to soft, compliant materials have led to the emergence of a new class of devices which can interact with humans safely, as well as reduce the disparity in mechanical compliance at the interface of soft human tissue and rigid devices.One of the largest application of soft materials has been in the field of flexible electronics, especially in wearable sensors. While wearable sensors for physical attributes such as strain, temperature, etc. have been popular, they lack applications and significance from a healthcare perspective. Point-of-care (POC) devices, on the other hand, provide exceptional healthcare value, bringing useful diagnostic tests to the bedside of the patient. POC devices, however, have been developed for only a limited number of health attributes. In this dissertation I propose and demonstrate wireless, wearable POC devices to measure and communicate the level of various analytes in and the properties of multiple biofluids: blood, urine, wound exudate, and sweat.
Along with sensors, another prominent area of soft materials application has been in actuators and robots which mimic biological systems not only in their action but also in their soft structure and actuation mechanisms. In this dissertation I develop design strategies to improve upon current soft robots by programming the storage of elastic strain energy. This strategy enables us to fabricate soft actuators capable of programmable and low energy consuming, yet high speed motion. Collectively, this dissertation demonstrates the use of soft compliant materials as the foundation for developing new sensors and actuators for human use and interaction.
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Sapsanis, Christos. "Capacitive Structures for Gas and Biological Sensing." Thesis, 2015. http://hdl.handle.net/10754/550470.
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The semiconductor industry was benefited by the advances in technology in the last decades. This fact has an impact on the sensors field, where the simple transducer was evolved into smart miniaturized multi-functional microsystems. However, commercially available gas and biological sensors are mostly bulky, expensive, and power-hungry, which act as obstacles to mass use. The aim of this work is gas and biological sensing using capacitive structures. Capacitive sensors were selected due to its design simplicity, low fabrication cost, and no DC power consumption.
In the first part, the dominant structure among interdigitated electrodes (IDEs), fractal curves (Peano and Hilbert) and Archimedean spiral was investigated from capacitance density perspective. The investigation consists of geometrical formula calculations, COMSOL Multiphysics simulations and cleanroom fabrication of the capacitors on a silicon substrate. Moreover, low-cost fabrication on flexible plastic PET substrate was conducted outside cleanroom with rapid prototyping using a maskless laser etching. The second part contains the humidity, Volatile Organic compounds (VOCs) and Ammonia sensing of polymers, Polyimide and Nafion, and metal-organic framework (MOF), Cu(bdc)2.xH2O using IDEs and tested in an automated gas setup for experiment control and data extraction. The last part includes the biological sensing of C - reactive protein (CRP) quantification, which is considered as a biomarker of being prone to cardiac diseases and Bovine serum albumin (BSA) protein quantification, which is used as a reference for quantifying unknown proteins.
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(9189602), Tran NH Nguyen. "Printable Electrochemical Biosensors for the Detection of Neurotransmitter and Other Biological Molecule." Thesis, 2020.
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Glutamate is the principal excitatory neurotransmitter in the central nervous system. As one of the most abundant neurotransmitters, glutamate plays an essential role in many processes of the central nervous system and beyond. As a result, any disruption that causes an abnormal glutamate level can significantly impact the central nervous system's neurological functions. Glutamate excitotoxicity is a neuropathology that persists in many neurodegenerative disorders such as Parkinson's and Alzheimer's disease as well as in the traumatic brain and spinal cord injuries. Thus, the ability to obtain precise information about the extracellular glutamate level in the living brain and spinal cord tissue may provide new insights into the fundamental understanding of glutamate in neurological disorders and neurophysiological phenomena.
Conventional bioanalytical techniques that characterize glutamate levels in vivo have a low spatiotemporal resolution that has impeded our understanding of this dynamic event. The electrochemical sensor has emerged as a promising solution that can satisfy the requirement for highly reliable and continuous monitoring methods with an excellent spatiotemporal resolution for the characterization of extracellular glutamate concentration. In this thesis, I present various amperometric biosensors fabricated using a simple direct ink writing technique for ex vivo and in vivo glutamate monitoring.
The amperometric biosensor is fabricated by immobilizing glutamate oxidase on nanocomposite electrodes made of platinum nanoparticles, multiwalled carbon nanotubes, and a conductive polymer. The biosensors demonstrate good sensitivity and selectivity that can be inserted into a spinal cord and measure extracellular glutamate concentration. Additionally, another type of glutamate biosensor is fabricated from commercially available activated carbon with platinum microparticles. We utilize astrocyte cell culture to demonstrate our biosensor's ability to monitor the glutamate uptake process. We also present a direct measurement of glutamate release from optogenetic stimulation in mouse primary visual cortex brain slides.
Moreover, we explore a new type of material, perovskite nickelate-Nafion heterostructure, to fabricate biosensors and measure glutamate inside the mouse brain. Finally, by utilizing the nanocomposite ink and direct ink writing technique, we also fabricate the gold-ruthenium non-enzymatic glucose biosensor. We apply a modified Butler-Volmer non-linear model to evaluate the impact of geometrical and chemical design parameters of non-enzymatic biosensor performance.
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Monteiro, Miguel Pedro da Conceição. "Flexible sensors technology for Point-Of-Care diagnostics with integrated micro fluidics on paper." Master's thesis, 2018. http://hdl.handle.net/10362/61574.
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Nowadays the hospitals and the medical centres face a huge challenge finding solutions to improve the efficiency of medical diagnosis.
The scope of this project was to develop a “Point-of-Care Diagnostic” (POCD) device, that can give a better alternative for genetic analysis, instead of the usual methods of PCR (polymerase chain reaction).
This device is composed by three layers. The first layer which works as a transporter and filter was built on paper. The second layer is the substitute of the regular thermocycling phase in the PCR technique and the third layer incorporates an interdigital capacitor that works as a DNA (deoxyribonucleic acid) sensor with high sensitivity to detect DNA hybridisation. These last two layers were made in kapton film.
The devices were produced with microfabrication methods using inkjet printing, lithographic and deposition processes.
The device’s characterisation was based on impedance spectroscopy methods.
With the purpose of testing the device, the capacitor was functionalised with the YWHAZ gene. However, this process can be performed with any other gene.
Due to its characteristics, the device under study was designed to run RT-qPCR (Real time quantitative polymerase chain reaction) and presents itself as an effective way to substitute the traditional PCR techniques. Even more, as the transport of samples to a laboratory and the recruitment of specialised personnel are not necessary, costs and response time are reduced.
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LIN, SI-HONG, and 林思宏. "The Study of Differential Reference Electrodes on Characteristics and Equivalent Circuit Impedance Analysis of the Flexible Arrayed Glucose and Ascorbic Acid Biosensors Based on AZO and ZnO Modified by Magnetic Beads and Graphene Oxide, and Integrated with Microfluidic Framework, and the Design of Readout Circuit." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/v2cgb5.
Full textAbstract:
碩士國立雲林科技大學
電子工程系
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In this thesis, the silver reference electrodes and conductive wires were printed onto a polyethylene terephthalate substrate (PET) by using screen printing technology. Next, aluminium-doped zinc oxide (AZO) or zinc oxide (ZnO) was deposited onto the silver electrodes by using the vacuum radio frequency (RF) sputtering system. The enzyme like glucose oxidase (GOx) or ascorbate oxidase (AO) was immobilized on the AZO or ZnO membranes to fabricate the glucose biosensor or the ascorbic acid biosensor, respectively. After that, graphene oxide (GO) and magnetic beads (MBs) were used to modify the sensing membranes. In terms of the analysis of sensing characteristics, average sensitivity, linearity, response time, limit of detection, drift, hysteresis, interference, lifetime, and temperature effects were investigated. Moreover, electrochemical impedance spectroscopy (EIS) was used to analyze the electrochemical impedance of different membranes. Finally, the sensing characteristics of the biosensor integrating with the microfluidic framework were analyzed, and the wireless sensing system based on ZigBee protocol integrating the biosensor was applied to realizing remote monitoring.