Academic literature on the topic 'Biosensor experiments'
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Journal articles on the topic "Biosensor experiments"
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Gómez-Gómez, Maribel, Ángela Ruiz-Tórtola, Daniel González-Lucas, María-José Bañuls, and Jaime García-Rupérez. "New Method for Online Regeneration of Silicon-Based Nanophotonic Biosensors." Proceedings 4, no. 1 (November 14, 2018): 22. http://dx.doi.org/10.3390/ecsa-5-05741.
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The optimal development of biosensors is a costly and time-consuming task, since an enormous amount of experiments is required. Therefore, the possibility of reusing the biosensors is highly desirable. In this work, a protocol based on the use of formamide for the regeneration of nanophotonic biosensors used for oligonucleotides detection is presented. This protocol was carried out online using the microfluidic system used to drive the target samples to the nanophotonic biosensor, thus allowing the possibility of running several experiments in a row using the same biosensor.
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Baronas, Romas, and Karolis Petrauskas. "Sudėtinės geometrinės struktūros biojutiklių kompiuterinis modeliavimas." Informacijos mokslai 56 (January 1, 2011): 156–62. http://dx.doi.org/10.15388/im.2011.0.3141.
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Biojutikliai yra analitiniai įrenginiai, skirti medžiagų koncentracijoms matuoti. Kuriant naujus biojutiklius reikia atlikti daug eksperimentų. Siekiant sumažinti atliekamų fizinių eksperimentų skaičių taikomas kompiuterinis biojutiklių veiksmo odeliavimas, kai įprastai kiekvienam struktūriškai naujam biojutikliui yra sudaromas matematinis modelis, tuomet jis keičiamas skirtuminiu, o jo lygčių sistemos sprendimas įgyvendinamas sudarant kompiuterinį modelį. Kiekvienas žingsnis reikalauja atidos ir turėtų būti automatizuotas. Straipsnyje yra pateikiamas biojutiklio metamodelis, leidžiantis formuluoti biojutiklių modelius dalykinės srities sąvokomis. Pasiūlytasis metamodelis aprašo biojutiklių modelius, formuluojamus dvimatėje erdvėje, apimančius biojutiklio struktūros, jo geometrinių savybių, biojutikliuose vykstančių reakcijų ir difuzijos procesų aprašus. Sudarius metamodelį, buvo sukurta programinė įranga, automatiškai sukonstruojanti kompiuterinį biojutiklio modelį pagal metamodeliosąvokomis išreikšto biojutiklio aprašą. Metamodelis ir programinė įranga buvo taikoma realiam biojutiklio modeliui sudaryti ir jo veiksmui modeliuoti kompiuteriniu būdu.", t. y. ištrinti žodžius "biojutiklių veiksmo.Computer-Aided Modeling of Biosensors with a Complex Geometrical StructureRomas Baronas, Karolis Petrauskas SummaryBiosensors are analytical devices used to measure the concentration of substances. When developing new biosensors, a lot of experiments are needed to be performed. Mathematical modeling of biosensors is used to decrease the number of physical experiments. Models of biosensors are usually created for each structurally unique biosensor by defining its mathematical model and the corresponding numerical approximation. Equations of the numerical model are then solved using computer programs, usually created for a particular model of the biosensor. Each of these steps requires a great attention and should be automated. The article presents a metamodel for a biosensor, enabling one to define models of biosensors in domain-specific terms. The proposed metamodel describes biosensor models, defined in the two-dimensional space and including definitions of the structure of a biosensor, its geometrical properties, reactions and diffusion processes taking place in it. Upon defining the metamodel, we compiled the computer software able to create computer models for biosensors from the models formulated according to the proposed metamodel. The metamodel was practically used to define a model for a real biosensor, and the biosensor modeling software was used to simulate its operation.
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Petrauskas, Karolis, and Romas Baronas. "Biojutiklių, modeliuojamų dvimatėje erdvėje, kompiuterinių modelių automatizuotas sudarymas." Informacijos mokslai 42, no. 43 (January 1, 2008): 108–13. http://dx.doi.org/10.15388/im.2008.0.3434.
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Biojutikliai yra plačiai naudojami tirti medžiagų koncentracijai tirpaluose. Viena pagrindinių biojutiklio sudedamųjų dalių yra fermentas. Fermentai yra gana brangios medžiagos, dėl to ir vykdyti eksperimentus yra brangu. Kuriant naujus biojutiklius tenka atlikti daug eksperimentų. Kad būtų sumažintas reikiamų eksperimentų skaičius, taikomas kompiuterinis biojutiklių veiksmo modeliavimas. Dažniausiai konkrečios geometrijos biojutikliui kuriamas konkretus jo kompiuterinis modelis. Šiame straipsnyje pristatoma sistema, kuri gali prisitaikyti prie konkrečios geometrijos biojutiklio. Sistema gali būti taikoma biojutikliams, kurių veiksmas aprašomas matematiniais modeliais, formuluojamais dvimatėje stačiakampėje srityje. Konkretaus biojutiklio matematinio modelio sprendinys komponuojamas parenkant konkrečius algoritmus.Computer aided model composition for biosensors modelled in two-dimensional spaceKarolis Petrauskas, Romas Baronas SummaryBiosensors are analytical devices that use biological components, usually enzymes, which catalyse the interaction with a target analyte. Biosensors are widely used in clinical, environment and industrial applications for the determination of species concentrations. In some applications of biosensors, enzymes are very expensive and only available in very limited quantity. In design of novel highly sensitive biosensors a lot of experiments are required. Computer simulation of the biosensor action is an effective way to decrease a number of physical experiments. This paper presents a system adaptive to a concrete geometry of the biosensor. The system may be applied for biosensors, the action of which can be described by a mathematical model formulated in a two dimensional space. A simulator for a concrete biosensor is generated from the detailed description of the biosensor action.eight: 18px;">
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Klyuchko, O. M., and P. V. Beloshitsky. "Biosensor concept and data input to biomedical infornation systems." Medical Informatics and Engineering, no. 3 (June 10, 2021): 51–69. http://dx.doi.org/10.11603/mie.1996-1960.2020.3.11698.
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Background. In present publication we generalized and analyzed deeply the experience of some biosensors studying in biophysical experiments with aim to incorporate them further to electronic information systems. Output biosensor electrical signals were input ones to electronic information system making their connection into joined bioinformation system. Materials and methods. Methods of comparative analysis of the characteristics of input and output electrical information signals of biosensor were applied; its physical and mathematical models were developed. For biosensor properties studies the methods of transmembrane electric currents recording in voltage-clamp mode as well as patch-clamp on hippocampal neuronal membranes were used. Results. Biosensor concept and their general characteristic were given, corresponding prototypes were observed. The physical model of biosensor was developed and some test results of this device were suggested. The biosensor was examined as abstraction in consistent unity of its functions: signal receiver — filter — analyzer — encoder/decoder. A brief mathematical description of biosensor functioning was given as well as corresponding algorithm. As a result of performed works the possibilities of this biosensor incorporation to bioinformation electronic systems were substantiated and the example of such system «EcoIS» was observed. Conclusion. In conclusion following results of the works were summarized. The detailed description of technical devices — biosensors as elements of biomedical information systems were done as well as analysis of electrical information signals at output of biosensor, its ability to encode information and detailed analysis of the possibility to incorporate this biotechnical device into electronic information systems due to biosensor output electricals signals.
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Uludağ, İnci, and Mustafa Kemal Sezgintürk. "Ultrasensitive and Cost-Effective Detection of Neuropeptide-Y by a Disposable Immunosensor: A New Functionalization Route for Indium-Tin Oxide Surface." Biosensors 12, no. 11 (October 26, 2022): 925. http://dx.doi.org/10.3390/bios12110925.
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Neuropeptide Y (NPY) is one of the most abundant neuropeptides in the human brain, and its levels in the blood change in neurodegenerative and neuroimmune disorders. This indicates that NPY may serve as a diagnostic and monitoring marker for associated disorders. In this paper, an electrochemical immunosensor was created to detect NPY biomarkers using a novel immobilization technique. The proposed biosensor system enables accurate, specific, cost-effective, and practical biomarker analysis. Indium tin oxide-coated polyethylene terephthalate (ITO-PET) sheets were treated with hexamethylene diisocyanate (HMDC) to covalently immobilize antibodies. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques were used to analyze each step of the biosensors. The proposed NPY biosensor has a broad linear detection range (0.01–100 pg mL−1), a low limit of detection (LOD) (0.02968 pg mL−1), and a low limit of quantification (LOQ) (0.0989 pg mL−1). Atomic force microscopy (AFM) was used to support in the optimization process, study the surface morphology, and visualize it. Studies of repeatability, reproducibility, storage, and Kramers–Kronig transformation were conducted during electrochemical characterization. After analytical experiments, the biosensor’s responses to human serum samples were evaluated. According to the obtained data, the error margin is small, and the created biosensor offers a great deal of promise for the clinical measurement of NPY.
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Skopis, Vladimir, and Igors Uteshevs. "Research in Adaptronic Automatic Control System and Biosensor System Modelling." Electrical, Control and Communication Engineering 8, no. 1 (July 1, 2015): 20–29. http://dx.doi.org/10.1515/ecce-2015-0003.
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Abstract This paper describes the research on adaptronic systems made by the author and offers to use biosensors that can be later inserted into the adaptronic systems. Adaptronic systems are based, on the one hand, on the adaptronic approach when the system is designed not to always meet the worst condition, but to change the structure of the system according to the external conditions. On the other hand, it is an extension of common automatic control ad adaptive systems. So, in the introduction firstly the adaptronic approach and biosensor as a term is explained. Adaptive systems, upon which adaptronic ones are based, are also mentioned. Then the construction of biosensor is described, as well as some information is given about the classification of biosensors and their main groups. Also it is suggested to use lichen indicators in industry to control concentration of chemical substances in the air. After that mathematical models and computer experiments for adaptronic system and biosensor analysis are given.
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Ma, Zhicong. "Effect Evaluation of Biomedical Experiment Teaching Based on Intelligent Sensor." Journal of Sensors 2022 (February 14, 2022): 1–10. http://dx.doi.org/10.1155/2022/2124462.
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With the continuous development and progress of nanotechnology, its biosensors have been widely used in biomedical experimental teaching, and good experimental results have been achieved. Graphene, as a new nanomaterial with large surface area, good thermal conductivity, and unique electrical conductivity, has unique advantages in the field of biosensor preparation. Based on this, this paper will prepare the electrochemical sensor applied to biomedical experimental teaching based on graphene, optimize the detection sensitivity and detection range of graphene electrochemical sensor based on the corresponding experimental conditions, and improve its corresponding stability and reusability. At the level of electrochemical activity of biosensors, this paper innovatively uses the electric AC impedance method to detect the electrochemical activity, so as to accurately evaluate the key characteristics of biosensors. Based on the preparation of biosensors and the results of biological experiments, this paper will design a network-based biomedical experiment teaching effect evaluation system, and realize the basic functions of teacher-student interaction, teaching effect evaluation, sensor performance evaluation and so on. Based on the above, the electrochemical sensor based on graphene and a conductive polymer solution is actually prepared in this paper. At the same time, the electrocatalysis experiment is carried out based on the sensor, and the experimental teaching effect is systematically evaluated. The experimental results show that the sensitivity of the biosensor proposed in this paper is increased by about 10% compared with the traditional biosensor, the corresponding preparation complexity is reduced by nearly 1/3, and the corresponding reusability is increased by 30%. Therefore, the biomedical experiment teaching effect evaluation system proposed in this paper has good evaluation effect. It can provide accurate reference for the evaluation of biological experiment teaching effect, so it has important value and significance.
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Antonova, Hanna, Yevgenia Babenko, Oleksandr Voronenko, Igor Galelyuka, Anna Kedych, and Oleksandra Kovyrova. "Biosensor Devices in the Production of Alcoholic and Non-Alcoholic Beverages." Cybernetics and Computer Technologies, no. 3 (September 30, 2021): 103–14. http://dx.doi.org/10.34229/2707-451x.21.3.9.
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"Smart" multisensors and biosensor systems based on modern information and communication technologies make it possible to qualitatively improve the parameters of testing systems for biologically active, chemical and toxic substances and biological or biophysical objects, improve parameter control, data processing and analysis in digital agriculture, food industry, environmental monitoring and other areas of human activity. These next-generation devices combine biologically sensitive elements with converters of biophysical signals into electrical digital signals. The article reveals the basic principles of construction of biosensor devices, their practical implementation and application. The own results of development of a wireless network of "smart" multisensors and biosensor devices for express diagnostics of a condition of grape and fruit crops and control of process of production of wine are presented. In order to test the capabilities of the unit of measurement, a number of experimental works were performed. To perform such work, it was first necessary to develop a new embedded software for the microprocessor of Analog Devices ADuCM350, and the corresponding user software for the OS Windows 10. Experiments were performed using disposable sensors based on the enzyme glucose oxidase to measure the sugar content in glucose and wine solution. A review and analysis of modern biosensor devices used in the production of alcoholic and Non-Alcoholic Beverages were done. The comparative table of analyzers for different studies based on biosensors is made. Development and preparation for mass production of "smart" biosensors, biosensor devices and networks based on them is in line with global scientific and technological trends of today and, of course, the near future. Keywords: biosensors, ammetric transducers, wireless sensor network, express diagnostics of grape and berry crops.
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RASOOLY, AVRAHAM. "Surface Plasmon Resonance Analysis of Staphylococcal Enterotoxin B in Food." Journal of Food Protection 64, no. 1 (January 1, 2001): 37–43. http://dx.doi.org/10.4315/0362-028x-64.1.37.
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Surface plasmon resonance (SPR) biosensors are electro-optical instruments used for analyzing real-time protein-protein interactions. This work evaluates an SPR biosensor (Biacore 3000) in the detection of staphylococcal enterotoxin B (SEB) in foods. A sandwich SPR immunosensor involving two antibodies was used. The capturing antibody, bound covalently to the surface of the biosensor chip, performs the initial binding of the antigen and a second antibody binds to the captured antigen. The second antibody makes antigen verification possible and amplifies the signal. Pure SEB as well as SEB in spiked foods (milk and meat) were detected with little interference from the food matrix. In the control experiments with uncontaminated food samples no significant signal was detected. The SPR biosensor assay detects SEB at ~10 ng/ml rapidly, with initial binding within 2 min. The entire measurement cycle (including washing and chip regeneration) may take 5 min using one antibody or 8 min using two antibodies. These results suggest that the SPR biosensor may be a useful tool for real-time analysis of toxin in foods.
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Klyuchko, Olena, Anatoliy Beletsky, Olga Gonchar, and Olga Melezhyk. "Bioinformation Systems with Detectors and Signal Coding Capabilities." Science and Innovation 18, no. 2 (April 30, 2022): 73–84. http://dx.doi.org/10.15407/scine18.02.073.
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Introduction. The integration of computer technologies into various fields of science allows the development of new methodologies, hybrid information systems with advanced capabilities, such as EcoIS bioinformation system for monitoring the environment with the use of biological data detectors.Problem Statement. The development of innovation bioinformation systems with biological data detectors is a very important task, as they have numerous advantages: allow rapid diagnostics and testing of chemicals in thefirst moments of their action, may be incorporated easily into electronic registration systems, may serve as elementary analytical units with data coding capabilities, etc.Purpose. The purpose of this research is to make a comprehensive analysis of different types of biological data detectors to develop a physical model of a biosensor capable of encoding signals and a bioinformation system with such detectors.Materials and Methods. The comparative analysis of information systems with functions of ecomonitoring and different types of biosensors have been used; the data are taken from electrophysiological experiments on registration of chemosensitive transmembrane electric currents in voltage clamp and patch clamp modes.Results. The physical model of biosensor has been developed and tested. The integration of the developed biosensors into the electronic bioinformation system by the example of EcoIS authors’ system has been demonstrated. Neuron-like biosensor has been considered an abstraction in the unity of its functions: signal receiver — filter — analyzer — encoder/decoder, where the input information is obtained in the form of chemical structures or electrical signals, after the conversion (recoding) of information it is registered as electrical signals with changed characteristics. The prospects for developing the cutting-edge methods for information protection in systems with biosensors have been shown. Conclusions. This development may be used for creating a bioinformation system for environmental moni toring with integrated biosensor system and data protection based on the principles and achievements of contemporary biophysics.
Dissertations / Theses on the topic "Biosensor experiments"
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Popov, Piotr. "LIQUID CRYSTAL INTERFACES: EXPERIMENTS, SIMULATIONS AND BIOSENSORS." Kent State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=kent1434926908.
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Pham, Errek Manh Trung. "Producing A Peptide For Use In A Blood Biosensor For Injury Detection." Youngstown State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1607519672342672.
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Ocaña, Tejada Cristina. "Aptasensors based on electrochemical impedance spectroscopy." Doctoral thesis, Universitat Autònoma de Barcelona, 2015. http://hdl.handle.net/10803/305103.
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En els últims anys, a causa de la necessitat de diàgnostics ràpids i de millores en sensat, s’han utilitzat nous elements de reconeixement en biosensors. Un tipus d’aquests nous elements de reconeixement són els aptàmers. Els aptàmers són cadenes sintètiques de ADN o ARN les quals són seleccionades in vitro i tenen la capacitat d’unir-se a proteïnes, ions, cèl.lules, fàrmacs i lligands de baix pes molecular, reconeixent les seves molècules diana amb alta afinitat i especificitat. Diversos biosensors basats en aptàmers, també anomenats aptasensors, han sigut desenvolupats recentment. D’entre totes les tècniques de transducció utilitzades en biosensors, l’Espectrocòpia Electroquímica d’Impedància ha sigut àmpliament emprada como a eina per caracteritzar la superficies de sensors i estudiar esdeveniments en el biosensat en la superficie d’elèctrodes. La característica més important que presenta aquesta tècnica és que no requereix cap espècie marcada per a la transducció, per tant, aquesta tècnica de detecció pot utilitzar-se per dissenyar protocols de detecció directa sense marcatge, evitant assajos més cars i laboriosos.
El principal objectiu d’aquesta tesi doctoral va ser el desenvolupament d’aptasensors utilitzant la tècnica electroquímica d’impedància esmentada anteriorment. Per a això, diferents tipus d’elèctrodes van ser utilitzats, tals com elèctrodes de compòsit grafit-epoxi, elèctrodes de biocompòsit grafit-epoxi modificats amb molècules d’avidina i elèctrodes comercials serigrafiats de nanotubs de carboni de paret múltiple.
El treball es va dividir principalmente en dues parts d'acord amb la detecció de dues proteïnes diferents.
La primera part es va focalitzar en la detecció de trombina. Primer de tot, es van comparar i avaluar diversos aptasensors de detecció directa sense marcatge basat en diferents tècniques d'immobilització dels aptàmers, tals com: adsorció física humida, afinitat avidina-biotina i enllaç covalent mitjançant activació electroquímica de la superfície de l'elèctrode i mitjançant inserció electroquímica. Posteriorment, els elèctrodes de biocompòsit van ser comparats com a plataformes en genosensat i aptasensat. Amb la finalitat d'amplificar el senyal impedimètric obtingut utilitzant elèctrodes de biocompòsit, un protocol sàndwich va ser emprat incloent nanopartícules d'or modificades amb estreptavidina i tractament amplificador de plata.
La segona part de l'estudi es va basar en la detecció de citocrom c. Primerament, es va realitzar un simple aptasensor de detecció directa sense marcatge per a la detecció d'aquesta proteïna utilitzant la tècnica d'immobilització d'adsorció física humida. Finalment, i amb l'objectiu d'amplificar el señal impedimètric, es va desenvolupar un assaig tipus sándwich híbrid d’aptàmer i anticòs utilitzant elèctrodes serigrafiats de nanotubs de carboni de paret múltiple.
D'aquesta manera, la tesi explora i compara una àmplia gamma de procediments d'immobilització, l'ús de detecció directa sense marcatge o nanomaterial modificat amb biomolècules en diferents protocols directes o d'amplificació, i l'ús de reconeixement directe i sándwich per amplificar la sensibilitat i/o la selectivitat de l'assaig.In the recent years, due to the need for rapid diagnosis and improvements in sensing, new recognition elements are employed in biosensors. One kind of these new recognition elements are aptamers. Aptamers are synthetic strands of DNA or RNA which are selected in vitro and have the ability to bind to proteins, ions, whole cells, drugs and low molecular weight ligands recognizing their target with high affinity and specificity. Several aptamer-based biosensors, also called aptasensors, have been recently developed. Among all the transduction techniques employed in biosensors, Electrochemical Impedance Spectroscopy has widely used as a tool for characterizing sensor platforms and for studying biosensing events at the surface of the electrodes. The important feature presented by this technique is that it does not require any labelled species for the transduction; thus, this detection technique can be used for designing label-free protocols thus avoiding more expensive and time-consuming assays. The main aim of this PhD work was the development of aptasensors using the electrochemical impedance technique previously mentioned for protein detection. For that, different types of electrodes were used, such as Graphite Epoxy Composite electrodes (GECs), Avidin Graphite Epoxy Composite electrodes (AvGECs) and commercial Multi-Walled carbon nanotubes screen printed electrodes (MWCNT-SPE). The work was divided in two main parts according to the detection of the two different proteins. The first part was focused on thrombin detection. First of all, different impedimetric label-free aptasensors based on several aptamer immobilization techniques such as wet physical adsorption, avidin-biotin affinity and covalent bond via electrochemical activation of the electrode surface and via electrochemical grafting were developed and evaluated. Then, AvGECs electrodes were compared as a platform for genosensing and aptasensing. With the aim to amplying the obtained impedimetric signal using AvGECs, an aptamer sandwich protocol for thrombin detection was used including streptavidin gold-nanoparticles (Strep-AuNPs) and silver enhancement treatment. The second part of the study was based on cytochrome c detection. Firstly, a simple label-free aptasensor for the detection of this protein using a wet physical adsorption immobilization technique was performed. Finally, with the goal to amplify the impedimetric signal, a hybrid aptamer-antibody sandwich assay using MWCNT-SPE for the detection of the target protein was carried out. In this way, the thesis explores and compares a wide scope of immobilization procedures, the use of label-free or nanocomponent modified biomolecules in different direct or amplified protocols, and the use of direct recognition and sandwich alternatives to enhance sensitivity and/or selectivity of the assay
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Sena, Torralba Amadeo. "Development and application of innovative point-of-care biosensing platforms." Doctoral thesis, Universitat Autònoma de Barcelona, 2020. http://hdl.handle.net/10803/670851.
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L'objectiu d'aquesta tesi ha estat el desenvolupament i l'aplicació de plataformes innovadores de biosensado en el punt d'atenció. La tesi es divideix en cinc capítols seguits d'una secció de conclusions generals. El capítol 1 comença amb una introducció general als conceptes de biosensors i biosensado en el punt d'atenció. Després, s'enfoca en una de les proves de punt d'atenció més reeixides: l'assaig de flux lateral (LFA). Els aspectes clau de l'assaig, com els components i reactius, els procediments de fabricació i operació estan coberts en profunditat. El capítol continua amb una revisió dels desafiaments actuals de LFA ha enfrontat i les millores més rellevants reportades en els últims anys. El Capítol 2 descriu breument els objectius que van motivar aquest treball. El capítol 3 presenta una nova plataforma de detecció (PEB) que combina les característiques clau d'un assaig de flux lateral, la prova de punt d'atenció més utilitzada, amb les capacitats de tractament de mostres de l'electroforesi. En particular, es demostra la capacitat de PEB per separar diferents tipus de partícules i detectar anticossos IgG humans en mostres de sang no tractades. Finalment, per fer que la plataforma sigui aplicable en el punt d'atenció, PEB es combina amb un telèfon intel·ligent que controla l'electroforesi i llegeix el senyal òptica generada. El Capítol 4 explica una estratègia simple i de baix cost per millorar el rendiment analític dels LFA. Mitjançant l'ús de barreres de cera solubles, les nanopartícules s'acumulen temporalment a la part superior de la línia de detecció (TL). Aquest pas estès d'incubació interna promou la formació de l'inmunocomplejo, generant una millora de sensibilitat i de senyal en comparació amb la detecció convencional de LFA per IgG humana (H-IgG). El capítol 5 presenta una plataforma de detecció en el punt d'atenció que consisteix en un microtub i dues peces de fibra de vidre. El principi de detecció es basa en la transferència d'energia de ressonància de Förster utilitzant nanoclústers d'or com a indicador de senyal i nanopartícules d'or conjugades amb anticossos com un desactivador. La plataforma ha estat validada per a la detecció d'Escherichia coli O157: H7 en aigua de riu i de l'aixeta, demostrant una elevada sensibilitat.El objetivo de esta tesis ha sido el desarrollo y la aplicación de plataformas innovadoras de biosensado en el punto de atención. La tesis se divide en cinco capítulos seguidos de una sección de conclusiones generales. El Capítulo 1 comienza con una introducción general a los conceptos de biosensores y biosensado en el punto de atención. Luego, se enfoca en una de las pruebas de punto de atención más exitosas: el ensayo de flujo lateral (LFA). Los aspectos clave del ensayo, como los componentes y reactivos, los procedimientos de fabricación y operación están cubiertos en profundidad. El capítulo continúa con una revisión de los desafíos actuales de LFA ha enfrentado y las mejoras más relevantes reportadas en los últimos años. El Capítulo 2 describe brevemente los objetivos que motivaron este trabajo. El Capítulo 3 presenta una nueva plataforma de detección (PEB) que combina las características clave de un ensayo de flujo lateral, la prueba de punto de atención más utilizada, con las capacidades de tratamiento de muestras de la electroforesis. En particular, se demuestra la capacidad de PEB para separar diferentes tipos de partículas y detectar anticuerpos IgG humanos en muestras de sangre no tratadas. Finalmente, para hacer que la plataforma sea aplicable en el punto de atención, PEB se combina con un teléfono inteligente que controla la electroforesis y lee la señal óptica generada. El Capítulo 4 explica una estrategia simple y de bajo costo para mejorar el rendimiento analítico de los LFA. Mediante el uso de barreras de cera solubles, las nanopartículas se acumulan temporalmente en la parte superior de la línea de detección (TL). Este paso extendido de incubación interna promueve la formación del inmunocomplejo, generando una mejora de sensibilidad y de señal en comparación con la detección convencional de LFA para IgG humana (H-IgG). El Capítulo 5 presenta una plataforma de detección en el punto de atención que consiste en un microtubo y dos piezas de fibra de vidrio. El principio de detección se basa en la transferencia de energía de resonancia de Förster utilizando nanoclusters de oro como indicador de señal y nanopartículas de oro conjugadas con anticuerpos como un desactivador. La plataforma ha sido validada para la detección de Escherichia coli O157: H7 en agua de río y del grifo, demostrando una elevada sensibilidad.
The objective of this thesis has been the development and application of innovative biosensing platforms at the point of care. The thesis is divided into five chapters followed by a section of general conclusions. Chapter 1 begins with a general introduction to the concepts of biosensors and point-of-care biosensing. Then, it focuses on one of the most successful point-of-care tests: the lateral flow test (LFA). Key aspects of the assay, such as components and reagents, manufacturing and operating procedures are covered in depth. The chapter continues with a review of the current challenges LFA has faced and the most relevant improvements reported in recent years. Chapter 2 briefly describes the objectives that motivated this work. Chapter 3 introduces a new detection platform (PEB) that combines the key features of a lateral flow assay, the most widely used point-of-care test, with the capabilities of electrophoresis sample treatment. In particular, the ability of PEB to separate different types of particles and detect human IgG antibodies in untreated blood samples is demonstrated. Finally, to make the platform applicable at the point of care, PEB is combined with a smartphone that controls the electrophoresis and reads the generated optical signal. Chapter 4 explains a simple, low-cost strategy to improve the analytical performance of LFAs. By using soluble wax barriers, nanoparticles temporarily accumulate at the top of the detection line (TL). This extended internal incubation step promotes immunocomplex formation, generating improved sensitivity and signal compared to conventional LFA detection for human IgG (H-IgG). Chapter 5 presents a point-of-care detection platform consisting of a microtube and two pieces of fiberglass. The detection principle is based on Förster resonance energy transfer using gold nanoclusters as a signal indicator and antibody-conjugated gold nanoparticles as a quencher. The platform has been validated for the detection of Escherichia coli O157: H7 in river and tap water, demonstrating high sensitivity.
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Carinelli, Soledad. "Biomarkers detection of global infectious diseases based on magnetic particles." Doctoral thesis, Universitat Autònoma de Barcelona, 2019. http://hdl.handle.net/10803/667765.
Full textAbstract:
Las enfermedades infecciosas suponen una gran amenaza para la salud mundial debido a la rápida diseminación y adaptación de los patógenos. El papel principal del diagnóstico clínico es identificar de forma fehaciente una enfermedad en un paciente. Los dispositivos de diagnóstico rápido permiten detectar enfermedades y monitorearlas de forma confiable en cualquier centro sanitario. Entre estos dispositivos, los biosensores electroquímicos presentan una alta sensibilidad y especificidad así como una instrumentación sencilla, pudiendo expandirse fácilmente a plataformas de detección múltiple. Además, la integración de partículas magnéticas (MPs) en métodos de diagnóstico rápido incrementa la sensibilidad y especificidad debido su capacidad para aislar y preconcentrar una molécula diana cuando éstas son modificadas con elementos de bioreconocimiento específico. Así, las MPs modificadas pueden unirse específicamente a biomarcadores y concentrarlos de muestras complejas bajo la actuación magnética, eliminando posibles interferencias. En esta tesis se presenta el desarrollo de estrategias de diagnóstico basados en tecnologías emergentes, asequibles y que requieren un entrenamiento mínimo de los usuarios finales, tales como los biosensores electroquímicos con accionamiento magnético.
Primero, se presentan dos tipos de pruebas diagnósticas para la cuantificación de linfocitos CD4 en sangre entera, usando MPs, para el seguimiento rápido de pacientes con HIV en entornos de bajos recursos. Se describen dos formatos, uno en formato tipo ELISA con detección óptica y otro usando electrodos de grafito-epoxi con biosensado electroquímico. En ambos casos la estrategia involucra a) el aislamiento de células CD4 usando MPs-antiCD3 y su marcación utilizando anticuerpos antiCD4 biotinilados; b) la marcación enzimática con estreptavidina-peroxidasa; y c) la detección basada en la actividad enzimática. Esta doble marcación (a través de los receptores CD3 yCD4) no sólo evita interferencias de otras células que expresan alguno de estos receptores, sino que aumenta la especificidad del ensayo.
Segundo, se describe un ensayo de liberación de interferon-basado en la detección electroquímica de dicho trascripto producido por linfocitos T previamente aislados de sangre. Este test utiliza MPs para el aislamiento y preconcentración de tres dianas diferentes (linfocitos T, mRNA y ADN doblemente marcado) en el mismo ensayo. Primero, los linfocitos T se aislan usando MPs-antiCD3. En segundo lugar, el mRNA de los linfocitos se preconcentra sobre MPs modificadas con polidT mediante unión a la cola de poli(A). Posteriormente se retrotranscribe el mRNA y se amplifica el cDNA mediante PCR múltiplex con marcación doble para la amplificación de IFN- y GAPDH. Finalmente, se inmovilizan los amplicones biotinilados en MPs-estreptavidina, y se realiza el genosensado electroquímico para la detección de IFN- a través del otro marcador del cebador. Esta estrategia se propone como alternativa a los ensayos de liberación de IFN- que se usan en la actualidad para la identificación de la Tuberculosis.
Por último, se presenta el diseño de un test de diagnóstico rápido, específico y altamente sensible basado en la amplificación isotérmica sobre MPs con detección electroquímica. Las técnicas de amplificación isotérmicas han surgido como una alternativa a la PCR para la identificación de microorganismos infecciosos, debido a la barrera que éstos últimos muestran para su implementación en entornos de bajos recursos. El último capítulo presenta la detección electroquímica de ADN usando sondas candado con amplificación isotérmica de círculo rodante y amplificación círculo a círculo. Esta estrategia ha demostrado ser una poderosa herramienta para la detección específica y sensible de ácidos nucleicos para su aplicación en el diagnóstico clínico.
Los biosensores desarrollados en esta tesis representan una gran promesa para la detección de forma más rápida, simple y económica comparado con los métodos tradicionales de diagnóstico de enfermedades infecciosas. Además, las estrategias desarrolladas en esta tesis demuestran un gran potencial para su aplicación en entornos de bajos recursos.Infectious diseases are becoming a major threat worldwide due to the fast dissemination and adaptation of pathogens favored by the unrestricted globalization. The primary role of diagnostics is to identify a disease. The rapid identification of a disease allows the patient to be placed on a specific antimicrobial therapy and avoid prolonged management on empiric, potentially inappropriate drug. Therefore, point-of-care (POC) devices that can reliably detect and/or monitor diseases would result in an improved care, and minimization of patient and societal cost of illness. Among them, electrochemical biosensors have the advantage of high sensitivity/specificity as well as simplicity of instrumentation, and can be easily expanded to multiplex detection platform. Furthermore, the integration of magnetic particles (MPs) in POC tests provides an even increased sensitivity and specificity due to the isolation and preconcentration of the target, whether MPs are modified with a specific recognition biomolecule. Modified-MPs can thus specifically bind the biomarkers and preconcentrate them from the complex specimen under magnetic actuation, preventing interferents before testing. Affordable emerging technologies requiring minimal training for final users, such as magnetic actuated electrochemical biosensors, are presented in this dissertation. Firstly, two simple diagnostic tests for CD4+ T lymphocytes quantification, directly in whole blood, and based on magnetic particles are presented. The assay is performed in an ELISA-like format for the optical detection or using graphite-epoxy electrodes for the electrochemical biosensing strategy. In both cases, the strategy has involved three main steps: a) immunomagnetic separation of CD4+ cells by antiCD3-MPs and labeling by using biotinylated antiCD4 antibody; b) enzymatic labeling; and c) detection based on the peroxidase activity. The dual labeling (CD3 and CD4 receptor) not only avoids interferences of other cells, but also increases the specificity of the assay. Thus, the development and evaluation of magnetic-actuated rapid HIV diagnostic platforms appropriate for their use in low resource settings for the following-up of patients under treatment is demonstrated. Secondly, an interferon- release assay based on electrochemical detection for interferon- transcript detection produced by isolated T lymphocytes is described. This approach also involves the integration of MPs for the isolation and preconcentration of three different targets (including whole T lymphocytes, mRNA transcripts and double-tagged DNA) in the same test. Accordingly, T lymphocytes are isolated from whole blood using antiCD3-MPs. Secondly, mRNA presenting poly(A) tail is preconcentrated on polydT-MPs from T lymphocyte. Afterward, mRNA is retrotranscripted and cDNA amplified by multiplex double-tagging PCR for the specific amplification of IFN- and GAPDH. Finally, one of the tags of the primers is used for the amplicons immobilization on streptavidin-MPs as support, while the electrochemical magneto-genosensing for transcript detection is performed using the other tag. This strategy results in an alternative for IFN- release assays, which can be used for identifying infectious states such as Tuberculosis. Finally, the design of a diagnostic test involving a rapid, specific and highly sensitive procedure based on isothermal amplification on MPs with electrochemical readout is presented. Isothermal amplification techniques are emerging as good candidates to replace PCR for the identification of infectious microorganism, since PCR-based method can be a critical barrier in low resource settings. An electrochemical DNA detection using padlock probes and the subsequent amplification with rolling circle and circle to circle amplification is presented in Chapter 6. This strategy has demonstrated to be a powerful combination for highly specific and sensitive nucleic acid detection that can be applied in clinical diagnosis. The electrochemical biosensors developed in this dissertation, offers considerable promise for obtaining information in a faster, simpler and cheaper manner compared to traditional methods for infectious disease diagnosis. Moreover, the strategies possess great potential in many applications, in low resource settings.
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Peláez, Gutiérrez Enelia Cristina. "Nanoplasmonic biosensors for clinical diagnosis, drug monitoring and therapeutic follow-up." Doctoral thesis, Universitat Autònoma de Barcelona, 2021. http://hdl.handle.net/10803/672028.
Full textAbstract:
Aquesta tesi doctoral té com a objectiu el desenvolupament de diversos biosensors que operen sense necessitat de marcatge addicional basats en dispositius plasmònics òptics per a la detecció directa de medicaments o biomarcadors relacionats amb diferents malalties i que són analitzats directament en mostres humanes com plasma, sèrum, orina o esput. Aquests dispositius biosensors ofereixen un sens fi de beneficis com és la seva alta sensibilitat, facilitat d’operació, l’obtenció de dades quantitatives, detecció sense marcatge en temps real, i comunament només necessiten d’un petit volum de mostra. Tot això converteix els biosensors plasmònics en eines analítiques molt adequades per al diagnòstic de malalties, el control de la medicació o el seguiment de teràpies personalitzades. El nostre grup d’investigació ha demostrat amb èxit la implementació de biosensors òptics basats en plasmònica i en fotònica de silici, inclòs el desenvolupament complet de bioaplicaciones, el que ha aplanat el camí de la seva futura transferència tecnològica per a la seva implementació com a dispositius Point-of-Care ( POC). Els biosensors desenvolupats en aquesta Tesi inclouen la seva optimització i validació completa amb mostres reals, exemplificant alguns desafiaments clínics en els quals aquests biosensors plasmònics poden superar importants limitacions de les tècniques d’anàlisi convencionals actuals, mostrant el seu potencial i versatilitat com a futurs dispositius POC per ser usats en les unitats d’atenció primària en salut o fins i tot en l’entorn domèstic per al propi autocontrol per part dels pacients.
La tesi està organitzada en sis capítols. El capítol 1 conté la introducció dels conceptes bàsics i l’estat de l’art sobre els avenços actuals en les tècniques de diagnòstic i control de malalties i / o teràpies i el paper que exerceixen els biosensors per millorar-los. El capítol 2 inclou una descripció detallada de les plataformes biosensoras emprades i una descripció general dels processos metodològics. El Capítol 3 descriu el desenvolupament d’un dispositiu nanoplasmónico per al control terapèutic de l’medicament acenocumarol, un anticoagulant comunament administrat directament en plasma humà. El Capítol 4 es centra en el desenvolupament d’un biosensor plasmónico que serveixi com a control de la dieta lliure de gluten que han de portar els pacients celíacs. El Capítol 5 descriu les estratègies desenvolupades per a la detecció de dos biomarcadors per al diagnòstic primerenc de tuberculosi en mostres d’esput. Finalment, el Capítol 6 explora la detecció de quatre autoanticossos específics associats amb l’aparició de l’tumor directament en el sèrum humà com biomarcadors potencials per al diagnòstic primerenc de el càncer colorectal.Esta Tesis Doctoral tiene como objetivo el desarrollo de diversos biosensores que operan sin necesidad de marcaje adicional basados en dispositivos plasmónicos ópticos para la detección directa de medicamentos o biomarcadores relacionados con diferentes enfermedades y que son analizados directamente en muestras humanas como plasma, suero, orina o esputo. Estos dispositivos biosensores ofrecen un sinnúmero de beneficios como es su alta sensibilidad, facilidad de operación, la obtención de datos cuantitativos, detección sin marcaje en tiempo real, y comúnmente sólo necesitan de un pequeño volumen de muestra. Todo esto convierte a los biosensores plasmónicos en herramientas analíticas muy adecuadas para el diagnóstico de enfermedades, el control de la medicación o el seguimiento de terapias personalizadas. Nuestro grupo de investigación ha demostrado exitosamente la implementación de biosensores ópticos basados en plasmónica y en fotónica de silicio, incluido el desarrollo completo de bioaplicaciones, lo que ha allanado el camino de su futura transferencia tecnológica para su implementación como dispositivos Point-of-Care (POC). Los biosensores desarrollados en esta Tesis incluyen su optimización y validación completa con muestras reales, ejemplificando algunos desafíos clínicos en los que dichos biosensores plasmónicos pueden superar importantes limitaciones de las técnicas de análisis convencionales actuales, mostrando su potencial y versatilidad como futuros dispositivos POC para ser usados en las unidades de atención primaria en salud o incluso en el entorno doméstico para el propio autocontrol por parte de los pacientes. La tesis está organizada en seis capítulos. El Capítulo 1 contiene la introducción de los conceptos básicos y el estado del arte sobre los avances actuales en las técnicas de diagnóstico y control de enfermedades y/o terapias y el papel que desempeñan los biosensores para mejorarlos. El Capítulo 2 incluye una descripción detallada de las plataformas biosensoras empleadas y una descripción general de los procesos metodológicos. El Capítulo 3 describe el desarrollo de un dispositivo nanoplasmónico para el control terapéutico del medicamento acenocumarol, un anticoagulante comúnmente administrado directamente en plasma humano. El Capítulo 4 se centra en el desarrollo de un biosensor plasmónico que sirva como control de la dieta libre de gluten que deben llevar los pacientes celíacos. El Capítulo 5 describe las estrategias desarrolladas para la detección de dos biomarcadores para el diagnóstico temprano de tuberculosis en muestras de esputo. Finalmente, el Capítulo 6 explora la detección de cuatro autoanticuerpos específicos asociados con la aparición del tumor directamente en el suero humano como biomarcadores potenciales para el diagnóstico temprano del cáncer colorrectal.
This Doctoral Thesis aims to the development of several label-free biosensing analytical strategies integrated within optical plasmonic devices for the direct detection of drugs or biomarkers related to different diseases in biological samples such as plasma, serum, urine, and sputum. These biosensor devices offer several benefits like their high sensitivity, ease of operation, quantitative data, label-free operation, and real-time detection, and commonly require a small sample volume. All this turn plasmonic biosensors into well-suited analytical tools for diagnosing diseases, monitoring medication, or for personalized therapies follow-up. Our research group has extensively demonstrated the successful conjunction of novel in-house optical biosensor configurations (like plasmonic and photonic-based designs) with the full demonstrations of bioapplications, which has paved the way for their potential technological transfer as Point-of-Care devices (POC) for clinical diagnostics. The biosensor assays here implemented, which include their full optimization and validation with real samples, exemplify clinical challenges where such biosensors can overcome limitations of current conventional analytical techniques. The results show the potential and versatility that plasmonic biosensors can offer as future POC devices placed in primary healthcare units or even in the household environment for patients’ self-monitoring. This thesis is organized into six chapters. Chapter 1 is the introductory one, which explains the basic concepts and the state of the art of the current advances in diagnosis and monitoring techniques of diseases and/or therapies and the role of biosensors to improve them. Chapter 2 includes a detailed description of the biosensor platforms employed and a general description of the methodological processes. Chapter 3 is related to the development of a nanoplasmonic device for the therapeutic monitoring of the drug acenocoumarol, a commonly administered anticoagulant, directly in human plasma. Chapter 4 focuses on the implementation of a plasmonic biosensor that monitors the gluten-free diet in urine in celiac patients. Chapter 5 describes the biosensing strategies developed for the detection of two biomarkers for the early diagnosis of tuberculosis in sputum samples. Finally, Chapter 6 explores the detection of four specific autoantibodies associated with the tumor onset directly in human serum as potential biomarkers for the early detection of colorectal cancer.
Universitat Autònoma de Barcelona. Programa de Doctorat en Química
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Otte, Ortiz Marinus Albertus. "Towards Highly Sensitive and Multiplexed Nanoplasmonic Biosensors." Doctoral thesis, Universitat Autònoma de Barcelona, 2013. http://hdl.handle.net/10803/117188.
Full textAbstract:
En esta tesis se ha abordado la caracterización de sensores LSPR refractométricos desde diferentes puntos de vista. En primer lugar, se presenta un análisis teórico y experimental de nanocápsulas cilíndricas (nanorods) de oro, comparando su capacidad sensora con sensores SPP convencionales. El estudio ha conducido al hallagzo de una región espectral con rendimiento sensor optimizado, y a la que se puede acceder llevando a cabo un diseño preciso y detallado de las nanoestructuras. Por otro lado, el análisis desvela un rendimiento superior de los LSPR comparado con los convencionales SPP, con atisbos de mejoras adicionales si se superan ciertos inconvenientes inherentes a estas plataformas biosensoras.
De cara a identificar y suprimir estos inconvenientes, se han empleado matrices de nanodiscos de oro como nanoestructura modelo. En primer lugar, se han analizado las influencias negativas que se derivan de las finas capas metálicas de adhesión y de los altos índices de refracción del sustrato que soporta a los nanodiscos. Se ha demostrado que la elección adecuada del material y del espesor de estas capas de adhesión mejora significativamente la relación señal-ruido. Además, mediante la colocación de los
nanodiscos sobre nanopilares dieléctricos, alejándolos del sustrato, se han obtenido incrementos significativos de sensibilidad, proporcionando así una estrategia que se puede extender fácilmente a otros sistemas plasmónicos.
Se ha demostrado, por otro lado, que estas matrices de nanodiscos soportan un modo guiado, que, además de otras aplicaciones nanofotónicas interesantes, provoca un cambio en la radiación en campo lejano de estas estructuras que causa mejoras en sensibilidad y en la relación señal-ruido. Por último, se han combinado todos los conocimientos adqueridos y resultados obtenidos para esbozar la creación de un biosensor LSPR con funciones de multiplexado y con microfluídica integrada.In this dissertation, different aspects of refractometric nanoplasmonic sensors are discussed. First, a theoretical and experimental sensing performance assessment is made of Localized Surface Plasmon Resonance (LSPR) sensors based on single gold nanorods, by directly comparing them to conventional thin film Surface Plasmon Polariton (SPP) sensors. Besides the discovery of a material-specific optimized spectral sensing region that can be accessed via precise nanoparticle engineering, this work reveals a better biosensing performance for LSPR sensors that can be further improved if certain - inherent - drawbacks are overcome. For this, arrays of gold nanodisks are used to identify and suppress such drawbacks. First, negative influences that stem from thin metal adhesion layers and the high refractive indices of the supporting substrate are analyzed. It is shown that the right choice of material and thickness for these adhesion layers, significantly improves the signal-to-noise ratio (S/N)-values of these biosensors. Besides, by placing the nanodisks on nanopillars, thereby distancing them from the substrate, much higher sensitivities can be obtained, providing a strategy that can be easily expanded to other plasmonic systems. Next, it is demonstrated that the employed arrays of gold nanodisks support a guided mode that besides other interesting nanophotonics applications, alters the far-field radiation of these nanoplasmonic structures in such a manner, that both enhanced sensitivities and improved S/N-ratios are obtained. Finally, combining all gathered knowledge, a road map is sketched towards the creation of a LSPR sensor with multiplexing capabilities and integrated microfluidics.
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Alfonso, Pardo Wilmer. "Development of electrochemical platforms for DNA sensing." Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/397662.
Full textAbstract:
The present doctoral thesis is framed in the research and development (R & D) project between a private biotechnology company of molecular diagnostics Genomica SAU, the Institute for Bioengineering of Catalonia (IBEC), the University of Barcelona, and the Microfluidics ChipShop Company. The main objective of the project is making, implementation and marketing of a diagnostic device for early detection of DNA sequences involved with cancer. The multi device, or lab-on-chip (LOC), consists of a central automation unit (CAU), a system in miniature of DNA amplification or chain reaction polymerase (mini-PCR), and a biosensing platform (DNA chip) that consisting of a matrix or electrochemical array. The three elements are integrated by a microfluidic system in sandwich format cartridge.
For this purpose, the aim of this thesis was the creation, characterization and optimization of the biochemical recognition platform between two single strands of DNA of dissimilar lengths but with some complementary sequences for the subsequent electrochemical detection of a hybridization event between them. Then, the integration into the cartridge of above platform was done. For the creation of this platform, we chose to use a self-assembled monolayer (SAM) of thiols as biorecognition interface of the 14 DNA sequences that are part of the project. During optimization of the interface chips individual gold and various molecules were used being chosen the molecule with two arms disulfide of polyethylene glycol (PEG) and a malaimida group at the end of one of them. This linker (or MalPEG linker) reacts with the gold surface due to the dative interaction between the sulfur atoms of the disulfide and the gold atoms from the surface of the chips. At the same time, the malaimida group reacts with the thiol group of the capture probes, joining. The PEG groups function as anti-adhesion molecules. Surface plasmon resonance (SPR) and cyclic voltammetry (CV) were techniques used to characterize the substrate and the hybridization event.
For the manufacture of the cartridge, this was divided into two main blocks, the biosensing or electrochemical block and PCR block. The electrochemical block is composed of 4 layers, one of 64 working electrodes and gold paths for contact with the potentiostat, another layer that defines the area of the sensors must be functionalized gold and isolating the gold surface of the tracks. The third layer is a double-sided adhesive that has a hexagonal hole working as hybridization chamber, and the last layer is a screen printing layer with the reference electrode (RE) and counter electrodes. The above layers form an electrochemical cell wherein the hybridization will occurs. Regarding the PCR block, this is a system of two layers with a type microfluidic channel kind loop and its function is to contain the solutions during the process of DNA amplification by the mini-PCR.
During the integration of the optimized SAM into an electrochemical cartridge a manual and automated ways were used to immobilize the capture probes. Several tests were performed in order to obtain the best conditions and ratios between the molecules to maximize the hybridization signal during the electrochemical detection.El presente trabajo de tesis está enmarcado en un proyecto de investigación y desarrollo (I+D) entre la empresa privada Genomica S.A.U., el Instituto de Bioingeniería de Cataluña (IBEC), la Universidad de Barcelona y la empresa alemana ChipShop Microfluidics. El objetivo principal es el desarrollo, puesta a punto y comercialización de un dispositivo electroquímico de diagnóstico médico para etapas tempranas de cáncer. El objetivo de la tesis es la creación, optimización y posterior integración de una interfaz de biosensado de ADN en el dispositivo de diagnóstico, siendo pieza fundamental en el desarrollo de éste. La interfaz escogida fue una monocapa autoensamblada (SAM) que hace las veces de biosensor y que es capaz de anclar secuencias de ADN como sondas de captura y así poder detectar, selectivamente, las secuencias objetivo complementarias. El dispositivo también cuenta con un sistema microfluídico y un sistema de amplificación de ADN de reacción en cadena de la polimerasa en miniatura. La SAM esta inmovilizada en un array electroquímico que consta de 64 electrodos de trabajo que funcionan como elemento transductor de la señal electroquímica redox de los eventos de hibridación que ocurren sobre ellos. La funcionalización y puesta a punto del dispositivo se llevó a cabo inmovilizando múltiples sondas de captura después de una optimización de las concentraciones entre las diferentes partes constituyentes de la monocapa. Técnicas ópticas y electroquímicas fueron utilizadas para la caracterización de cada etapa y técnicas de fotolitografiado y de impresión por pantalla fueron utilizadas para la fabricación de los componentes del dispositivo. Finalmente, y después de algunos cambios surgidos durante el desarrollo del dispositivo, se llega a un diseño final y a las pruebas con muestras reales, proceso que aún está en etapa experimental.
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Bergua, Canudo José Francisco. "Nanobiosensors for contaminants detection in water." Doctoral thesis, TDX (Tesis Doctorals en Xarxa), 2020. http://hdl.handle.net/10803/670394.
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Aquesta tesi té com a objectiu desenvolupar biosensors per al monitoratge ambiental. Primer, s'ha desenvolupat un biosensor colorimètric basat en lateral flow strips (LFS) per a la detecció i quantificació d'Escherichia coli com a indicador fecal universal. En aquest cas, nanopartícules d'or (AuNP) s'utilitzen com a transductors òptics i anticossos policlonals com a elements de bioreconeixement per capturar, marcar i indicar la presència del bacteri. Paral·lelament, s'ha desenvolupat un sistema de filtració per millorar la sensibilitat dels LFS. L'optimització del flux de la mostra a través dels diferents materials s'ha realitzat mitjançant una tècnica innovadora basada en el seguiment del flux del bacteri bioluminescent Aliivibrio fischeri, similar en grandària i forma a E. coli. Finalment, aquests LFS s'han provat amb mostres d'aigua de rius i aigües residuals, mostrant una sensibilitat similar i bona reproductibilitat i selectivitat en tots els casos.
En segon lloc, s'ha desenvolupat un biosensor de toxicitat bioluminescent per a la detecció i quantificació de pesticides en mostres d'aigua. En particular, Aliivibrio fischeri, un bacteri bioluminescent, s'ha utilitzat com a element de bioreconeixement i transductor perquè augmenta i disminueix la bioluminescència d'acord amb la concentració de compostos tòxics en les mostres d'aigua. A més, l'òxid de grafè (GO) s'ha utilitzat com un potenciador del creixement no específic per promoure el creixement bacterià i augmentar la sensibilitat del sistema al detectar parcialment la bioluminescència emesa per A. fischeri. La detecció i quantificació de la bioluminescència es va realitzar amb un telèfon mòbil que permet una avaluació de la toxicitat de l'aigua de forma portàtil, més barata, i més fàcil d'utilitzar que els estàndards en els laboratoris.
En tercer lloc, s'ha desenvolupat una plataforma portàtil basada en un telèfon mòbil per a realitzar assajos que requereixen una detecció òptica, incloent assaigs colorimètrics, fluorescents i bioluminescents. Aquesta plataforma s'ha utilitzat per dur a terme i analitzar proves ELISA estàndard basades en resultats colorimètrics per a la detecció de la immunoglobulina humana i una proteïna del coronavirus. A més, el sistema permet realitzar un seguiment de l'agregació de AuNPs en funció del color de la solució. D'altra banda, la plataforma s'ha utilitzat per detectar i quantificar quantum dots (QD) i altres indicadors fluorescents (per exemple, fluoresceïna), i per a fer proves ELISA fluorescents basades en aquests transductors. A més, la plataforma permet realitzar lectures bioluminiscents amb aplicacions com l'anàlisi de la toxicitat de l'aigua. Finalment, la plataforma és útil per al cultiu de bacteris, mesuraments de terbolesa i detecció de resistència a antibiòtics.Esta tesis tiene como objetivo desarrollar biosensores para el monitoreo ambiental. Primero, se ha desarrollado un biosensor colorimétrico basado en lateral flow strips (LFS) para la detección y cuantificación de Escherichia coli como indicador fecal universal. En este caso, nanopartículas de oro (AuNP) se utilizan como transductores ópticos y anticuerpos policlonales como elementos de bioreconocimiento para capturar, marcar e indicar la presencia de la bacteria. Paralelamente, se ha desarrollado un sistema de filtración para mejorar la sensibilidad de las LFS. La optimización del flujo de la muestra a través de los diferentes materiales ha realizado mediante una técnica innovadora basada en el seguimiento del flujo de la bacteria bioluminiscente Aliivibrio fischeri, similar en tamaño y forma a E. coli. Finalmente, estos LFB se han probado con muestras de agua de ríos y aguas residuales, mostrando una sensibilidad similar y buena reproducibilidad y selectividad en todos los casos. En segundo lugar, se ha desarrollado un biosensor de toxicidad bioluminiscente para la detección y cuantificación de pesticidas en muestras de agua. En particular, Aliivibrio fischeri, una bacteria bioluminiscente, se ha utilizado como elemento de bioreconocimiento y transductor porque aumenta y disminuye la bioluminiscencia de acuerdo con la concentración de compuestos tóxicos en las muestras de agua. Además, el óxido de grafeno (GO) se ha utilizado como un potenciador del crecimiento no específico para promover el crecimiento bacteriano y aumentar la sensibilidad del sistema al detectar parcialmente la bioluminiscencia emitida por A. fischeri. La detección y cuantificación de la bioluminiscencia se realizó con un teléfono móvil que permite una evaluación de la toxicidad del agua de forma portátil, más barata, y más fácil de usar que los estándares en los laboratorios. En tercer lugar, se ha desarrollado una plataforma portátil basada en un teléfono móvil para realizar ensayos que requieren una detección óptica, incluyendo ensayos colorimétricos, fluorescentes y bioluminiscentes. Esta plataforma se ha utilizado para llevar a cabo y analizar pruebas ELISA estándar basadas en resultados colorimétricos para la detección de la inmunoglobulina humana y una proteína del coronavirus. Además, el sistema permite realizar un seguimiento de la agregación de AuNPs en función del color de la solución. Por otro lado, la plataforma se ha utilizado para detectar y cuantificar quantum dots (QD) y otros indicadores fluorescentes (por ejemplo, fluoresceína), así como para realizar pruebas ELISA fluorescentes basadas en estos transductores. Además, la plataforma permite realizar lecturas bioluminiscentes con aplicaciones como el análisis de la toxicidad del agua. Finalmente, la plataforma es útil para el cultivo de bacterias, mediciones de turbidez y detección de resistencia a antibióticos.
This thesis aims to develop biosensing tools for environmental monitoring. First, a colorimetric lateral flow biosensor (LFB) has been developed for the detection and quantification of Escherichia coli as a universal fecal indicator. Gold nanoparticles (AuNPs) are used as optical transducers and polyclonal antibodies as the biorecognition elements to capture, tag and indicate the presence of the bacteria. In parallel, a filtration system has been developed to improve the sensitivity of the LFBs. The optimization of the flow properties of the different lateral flow materials has been done by an innovative technique based on the tracking of the flow of the bioluminescent bacteria Aliivibrio fischeri, similar in size and shape to E. coli. Eventually, these LFBs have been tested with river and sewage waters, showing similar sensitivity and good reproducibility and selectivity in all the cases. Second, a bioluminescent toxicity biosensor has been developed for the detection and quantification of pesticides in water samples. In particular, Aliivibrio fischeri, a bioluminescent bacteria, has been used as the biorecognition element and the transducer because it turns up and down bioluminescence according to the concentration of toxic compounds within the water samples. Besides, graphene-oxide (GO) has been used as a non-specific growth enhancer to promote bacterial growth and increase the sensitivity of the system by partially screening the bioluminescence emitted by A. fischeri. The detection and quantification of the bioluminescence has been performed by a smartphone that allows for a cheaper, more user friendly, and portable water toxicity assessment. Third, a smartphone-based portable platform has been developed for the performance of optical sensing, including colorimetric, fluorescent, and bioluminescent assays. This platform has been used to perform and read standard ELISA tests based on colorimetric outputs for human IgG and coronavirus detection. In addition, the system allows for tracking AuNPs aggregation based on the color output of the solution. On the other hand, the platform has been used to detect and quantify quantum dots (QDs) and other fluorescent reporters (i.e. fluorescein), as well as performing fluorescent ELISA tests based on these transducers. Next, the platform allows for bioluminescent readouts with applications in toxicity analysis. Eventually, the platform is suitable for bacteria culture, turbidity measurements, and drug screening for antibiotic resistances assessment.
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Diéguez, Moure Lorena. "Optical grating coupler biosensor and biomedical applications." Doctoral thesis, Universitat de Barcelona, 2012. http://hdl.handle.net/10803/101149.
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Biosensors are nowadays a powerful tool to enable the detection of specific biological interactions and to evaluate the concentration dependence in the response. A biosensor usually consists of three different parts: the sample to be measured, the transducer and the electronic system that amplifies the signal, analyzes the data and brings a result to the final user. The transducer includes the bioreceptor (which specifically interacts with the sample) and the interface that transforms the recognition from the bioreceptor into a measurable signal. When the analyte interacts with the bioreceptor, the transducer sends a signal that is processed by the electronics. All this process occurs in an efficient, quick, cheap, easy, simple and specific way. Regarding the type of the transductor, the biosensors can be electrochemical, optical, acoustic, magnetic or thermometric; but overall the most powerful ones are the optical biosensors, and among them the grating coupler. As a technique for investigating processes at the solid/liquid interface, presents high mechanical stability, immunity to electromagnetic interferences and pushes the sensitivity to levels even higher than other techniques and allows for the direct monitoring of macromolecular adsorption. Taking advantage of the last advances in nanotechnology, the goal of this thesis is to study the versatility of an Optical Grating Coupler Biosensor. The design of new grating sensor chips will be investigated, a new calibration technique for the sensors will be proposed and, taking advantage of the technique, different biomedical scenarios will be tested.Esta tesis consiste en el diseño, fabricación y test de un Biosensor Óptico basado en redes de difracción y sus aplicaciones en biomedicina. Los biosensores ópticos son dispositivos que detectan interacciones biomoleculares específicas mediante un transductor óptico. Exhiben alta sensibilidad, alta estabilidad mecánica, son inmunes a las interferencias electromagnéticas y permiten medidas no destructivas. En los Biosensores Ópticos por Onda Evanescente un modo guiado se propaga a lo largo de la guía de ondas mientras que la onda evanescente interactúa con la superficie del sensor, reconociendo cualquier interacción biomolecular que provoque una modificación en el índice de refracción efectivo de la guía óptica. En este caso, la inserción de luz láser en la guía óptica se produce con ayuda de una red de difracción grabada en la superficie del sensor. Para un ángulo muy preciso se excita un modo guiado. Como consecuencia de las reacciones en la superficie se produce un cambio en el ángulo de acoplo. La medida en tiempo real del ángulo de acoplo, en función de la actividad bioquímica en la superficie es la base de este tipo de biosensor óptico. El objetivo es fabricar sensores de bajo coste en polímero y también en distintos materiales que permitan calibrar otras técnicas. Otro objetivo de esta tesis es la calibración de los sensores y de las distintas soluciones buffer comúnmente usadas en biosensado. Como aplicación, se ha usado un equipo comercial (Optical Waveguide Lightomode Spectroscopy, OWLS, MicroVacuum) para estudiar, mediante control electroquímico, el crecimiento y la liberación de multicapas de PLL/DNA para aplicaciones en administración de fármacos. También se ha usado el OWLS para optimizar la inmovilización de receptores olfativos en un dispositivo biosensor para el desarrollo de una nariz bioelectrónica.
Books on the topic "Biosensor experiments"
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Bartlett, Philip N. Bioelectrochemistry: Fundamentals, Experimental Techniques and Applications. Wiley & Sons, Incorporated, John, 2008.
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Department of Defense. Battlefield Medical Network: Biosensors in a Tactical Environment - Remote Health Monitoring, Telemetry, Traumatic Brain Injury , Bench and Field Experiments, Data Analysis and Findings. Independently Published, 2017.
Find full textBook chapters on the topic "Biosensor experiments"
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Káš, Jan, Miroslav Marek, Miloslav Šţastný, and Radek Volf. "Biosensors with electrochemical transducers." In Experimental Techniques in Bioelectrochemistry, 361–453. Basel: Birkhäuser Basel, 1995. http://dx.doi.org/10.1007/978-3-0348-7607-0_6.
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Juan Colás, José. "Fabrication and Experimental Techniques." In Dual-Mode Electro-photonic Silicon Biosensors, 37–57. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-60501-2_3.
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Pacios Pujadó, Mercè. "Experimental." In Carbon Nanotubes as Platforms for Biosensors with Electrochemical and Electronic Transduction, 83–117. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-31421-6_3.
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Kang, Kyung A., Nabil A. Anis, Mohee E. Eldefrawi, William Drohan, and Duane F. Bruley. "Reusable, Real-Time, Immuno-Optical Protein C Biosensor." In Advances in Experimental Medicine and Biology, 437–44. Boston, MA: Springer US, 1997. http://dx.doi.org/10.1007/978-1-4615-5865-1_56.
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Litescu, Simona Carmen, Sandra Eremia, and Gabriel Lucian Radu. "Biosensors for the Determination of Phenolic Metabolites." In Advances in Experimental Medicine and Biology, 234–40. Boston, MA: Springer US, 2010. http://dx.doi.org/10.1007/978-1-4419-7347-4_17.
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Lavecchia, Teresa, Arianna Tibuzzi, and Maria Teresa Giardi. "Biosensors for Functional Food Safety and Analysis." In Advances in Experimental Medicine and Biology, 267–81. Boston, MA: Springer US, 2010. http://dx.doi.org/10.1007/978-1-4419-7347-4_20.
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Spiker, James O., Kyung A. Kang, William Drohan, and Duane F. Bruley. "Protein C Detection Via Fluorophore Mediated Immuno-Optical Biosensor." In Advances in Experimental Medicine and Biology, 621–27. Boston, MA: Springer US, 1997. http://dx.doi.org/10.1007/978-1-4615-5399-1_87.
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Singh, Bal Ram, and Melissa A. Silvia. "Detection of Botulinum Neurotoxins Using Optical Fiber-Based Biosensor." In Advances in Experimental Medicine and Biology, 499–508. Boston, MA: Springer US, 1996. http://dx.doi.org/10.1007/978-1-4613-0361-9_40.
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Tang, Liang, and Kyung A. Kang. "Sensing Improvement of Protein C Biosensor by Sample Circulation." In Advances in Experimental Medicine and Biology, 177–82. Boston, MA: Springer US, 2003. http://dx.doi.org/10.1007/978-1-4757-6125-2_25.
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Spiker, James O., William N. Drohan, and Kyung A. Kang. "Reusability Study of Fiber Optic Based Protein C Biosensor." In Advances in Experimental Medicine and Biology, 731–39. Boston, MA: Springer US, 1999. http://dx.doi.org/10.1007/978-1-4615-4717-4_84.
Full textConference papers on the topic "Biosensor experiments"
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Liang, Pei, Qi Jiang, and Tianpeng Zhang. "Researches and experiments on reflective TFBG — SPR biosensor." In 2017 Chinese Automation Congress (CAC). IEEE, 2017. http://dx.doi.org/10.1109/cac.2017.8242941.
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Pepłowski, Andrzej, Daniel Janczak, and Małgorzata Jakubowska. "Stabilization of glucose-oxidase in the graphene paste for screen-printed glucose biosensor." In XXXVI Symposium on Photonics Applications in Astronomy, Communications, Industry, and High-Energy Physics Experiments (Wilga 2015), edited by Ryszard S. Romaniuk. SPIE, 2015. http://dx.doi.org/10.1117/12.2205830.
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Slawinski, Piotr R., Weston M. Lewis, and Benjamin S. Terry. "Performance Assessment of a Noninvasive Swallowable Biosensor Deployment System in Microgravity." In ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-65039.
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Ingestible capsule endoscope technology has been a topic of research since the middle of the 20th century and has become a prominent area of study since the commercialization of capsule endoscopy in 2000. Ingestible telemetry capsules have been investigated by NASA in the last 20 years as a means for monitoring human body temperature during periods of physical exhaustion, but are limited in sensing time due to passage through the digestive system. In this work, we present a feasibility study on a sensor that attaches to the intestinal mucosa after being delivered to the bowel via ingestible capsule to be used on long distance space flights. This study included experiments conducted on NASA’s Weightless Wonder aircraft and replicated in a laboratory setting on the ground. During these experiments, a capsule was activated, manually inserted into excised porcine small intestine, and then automatically implanted a sham sensor onto the mucosal lining. The purpose of the experiment was to determine if the automated implantation sequence is affected by microgravity. Eight trials conducted in each setting yielded successful implantation of four sham sensors in microgravity and three in earth gravity. Results suggest that automated implantation is feasible in both 1G and microgravity environments though design changes are necessary to significantly improve repeatability in both environments. Though improvements in reliability of the device are needed, this experiment is a benchmark for transferring capsule technology currently used only for visual screening of the bowel to health monitoring systems for space flights.
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Kowalski, Gregory J., Amir Talakoub, and Dale Larson. "Thermal Management Design of a Nanoscale Biocalorimeter." In ASME 2007 InterPACK Conference collocated with the ASME/JSME 2007 Thermal Engineering Heat Transfer Summer Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/ipack2007-33404.
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A nanoscale calorimeter design based on temperature induced changes in a surface plasmon based photonics effect has the potential to decrease the mass of experimental compounds consumed and to increase the throughput of experiments investigating drug development. This calorimeter is based on a demonstrated surface plasmon biosensor in which index of refraction changes as small as 10−5 % caused by biochemical reactions on the sensor surface are detected. To achieve this sensitivity require that the device’s temperature be held constant to within ± 0.001 K. In the biosensor the temperature was held constant to measure the concentration changes. For the calorimeter the concentration is held constant and temperature changes are monitored. In the calorimeter design the nanohole array sensor will be used as a sensitive thermometer that will be used to determine the enthalpy of binding, equilibrium binding constant and entropy changes of biochemical reactions. The numerical analysis described in this work demonstrates that nanoscale calorimetry is possible. The simulations demonstrate that two designs can produce temperature rises of 5.5 and 40 C, respectively well above the (10−3) C resolution of the sensors. These results were obtained using less than three orders of magnitude less reactants than is currently being used in calorimetry studies which is a significant advance of this technology.
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Sigurdson, M., C. Meinhart, and D. Wang. "AC Electrokinetics for Biosensors." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-62013.
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We develop here tools for speeding up binding in a biosensor device through augmenting diffusive transport, applicable to immunoassays as well as DNA hybridization, and to a variety of formats, from microfluidic to microarray. AC electric fields generate the fluid motion through the well documented but unexploited phenomenon, Electrothermal Flow, where the circulating flow redirects or stirs the fluid, providing more binding opportunities between suspended and wall-immobilized molecules. Numerical simulations predict a factor of up to 8 increase in binding rate for an immunoassay under reasonable conditions. Preliminary experiments show qualitatively higher binding after 15 minutes. In certain applications, dielectrophoretic capture of passing molecules, when combined with electrothermal flow, can increase local analyte concentration and further enhance binding.
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Schulz, Mark J., Amos Doepke, Xuefei Guo, Julia Kuhlmann, Brian Halsall, William Heineman, Zhongyun Dong, et al. "Responsive Biosensors for Biodegradable Magnesium Implants." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-13101.
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A biosensor is an electronic device that measures biologically important parameters. An example is a sensor that measures the chemicals and materials released during corrosion of a biodegradable magnesium implant that impact surrounding cells, tissues and organs. A responsive biosensor is a biosensor that responds to its own measurements. An example is a sensor that measures the corrosion of an implant and automatically adjusts (slows down or speeds up) the corrosion rate. The University of Cincinnati, the University of Pittsburgh, North Carolina A&T State University, and the Hannover Medical Institute are collaborators in an NSF Engineering Research Center (ERC) for Revolutionizing Metallic Biomaterials (RBM). The center will use responsive sensors in experimental test beds to develop biodegradable magnesium implants. Our goal is to develop biodegradable implants that combine novel bioengineered materials based on magnesium alloys, miniature sensor devices that monitor and control the corrosion, and coatings that slow corrosion and release biological factors and drugs that will promote healing in surrounding tissues. Responsive biosensors will monitor what is happening at the interface between the implant and tissue to ensure that the implant is effective, biosafe, and provides appropriate strength while degrading. Corrosion behavior is a critical factor in the design of the implant. The corrosion behavior of implants will be studied using biosensors and through mathematical modeling. Design guidelines will be developed to predict the degradation rate of implants, and to predict and further study toxicity arising from corrosion products (i.e., Mg ion concentrations, pH levels, and hydrogen gas evolution). Knowing the corrosion rate will allow estimations to be made of implant strength and toxicity risk throughout the degradation process.
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Sasoglu, F. Mert, Devrim Kilinc, Kathleen Allen, and Bradley Layton. "Parallel Force Measurement in Cell Arrays." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-42472.
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The primary goal of this work is to establish a robust, repeatable method for growing forebrain nerve cells in a parallel manner by stretching them using a microfabricated PDMS beam array and printing arrays of neurons. The highly compliant, transparent, biocompatible PDMS micro beam array may offer a method for more rapid throughput in cell and protein mechanics force measurement experiments with sensitivities necessary for highly compliant structures such as axons. This work has two endpoints. One is to use a neural array as an experimental testbed for investigating neuronal cell growth hypotheses. The other endpoint is to build a neuronal-based, biosensor device capable of acting as a cell-based sensor. We present preliminary results for microbeams attaching to nerve cells. The attachment ratio the life-length and the axon lengths of the chick forebrain cells on microprinted spots will also be compared with an equivalent protein coated area of cells.
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Faegh, Samira, and Nader Jalili. "Ultra Sensitive Piezoelectric-Based Microcantilever Sensor Operating at High Modes for Detection of Ultrasmall Masses." In ASME 2013 Dynamic Systems and Control Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/dscc2013-3938.
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Detection of ultrasmall masses such as proteins and pathogens has been made possible as a result of nano-technological advancements. Development of label-free and highly sensitive biosensors has enabled the transduction of molecular recognition into detectable physical quantities. MicroCantilever (MC)-based systems have played a widespread role in developing such biosensors. One of the most important drawbacks of the available biosensors their high cost. Moreover, biosensors are normally quipped with external devices such as actuator and read out systems which are bulky and expensive. A unique self-sensing detection technique is proposed in this paper in order to address the limitations of the measurement systems. A number of approaches have been reported for enhancing the sensitivity of MC-based systems including geometry modification, employing nanoparticle-enhanced MCs and operating MCs in lateral and torsional modes. Although being investigated, there have not been analytical high fidelity models describing comprehensive dynamics and behavior of MCs operating in high modes. In this study, a comprehensive mathematical modeling is presented for the proposed self-sensing detection platform operating at ultrahigh mode using distributed-parameters system modeling. Mode convergence theory was adopted to have an accurate level of estimation. An extensive experimental setup was built using piezoelectric MC operating at high mode which verified theoretical modeling results. Finally, the whole platform was utilized as a biosensor for detection of ultrasmall adsorbed mass along with the theoretical and experimental results and verification. It was proved that operating MC at ultrahigh mode increases the sensitivity of system to detect adsorbed mass as a result of increased quality factor.
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Wang, Li, David M. Sipe, and Qiao Lin. "Modeling and Characterization of MEMS Thermal Biosensors." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-61769.
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In this paper, a closed-form analytical model, which considers the coupling of heat transfer effects and enzymatic reaction kinetics, is developed to describe the behavior of MEMS thermal biosensors for substrate detection either in flow-injection mode or flow-through mode. Simulation results show that the maximum thermopile output voltage is saturated at higher substrate concentrations for flow-injection mode. For flow-through mode, there exists an optimal flow rate which corresponds to the maximum thermopile output voltage. The optimal flow rate is inversely proportional to the concentration of the substrate involved in the reaction. A prototype MEMS thermal biosensor is fabricated and tested. The validity of the models is verified by comparison to the experimental results.
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Mitra, Sushanta K., and Prasanna S. Gandhi. "Micro-Scale Analysis, Fabrication and Characterization of Devices in SMAµL IIT Bombay." In ASME 4th International Conference on Nanochannels, Microchannels, and Minichannels. ASMEDC, 2006. http://dx.doi.org/10.1115/icnmm2006-96028.
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Experimental and numerical investigations of liquid flows in the microchannels (50 150 μm) have been carried out for straight and serpentine geometry. CFD-ACE+ is used as numerical tool for analyzing flow through channels with designed roughness elements. μ-PIV is used for characterizing the flow through straight and serpentine sections of the channels. Such laser-based non-intrusive measurement technique is also used to characterize a microfluidic device meant for detection of multiple species. This device is fabricated from a mask using Excimer laser and species detection is achieved by balancing the pressure driven flow with the applied electric field. This device can be used for separation of biological species. In a parallel effort, experimental and numerical investigation of mechanics of affinity cantilevers for biosensor application has been carried out. A new model based on electrostatic repulsion between charged antigens has been proposed. Fabrication of biosensor is carried out on our Excimer laser. A characterization tool, micromap 5010, is used to measure static displacements resulting from bioactivity. A microfabrication facility to fabricate three-dimensional microstructures based on microstereolithography principles has been developed here. This facility will be useful for fabrication and further analysis (using μ-PIV) of flow through complex biological structures. Overall the SMAμL has a solid foundation laid for investigation of complex microchannel flow, heat transfer, biosensors and other MEMS devices.
Reports on the topic "Biosensor experiments"
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Hellinga, Homme W. Development of Combined Computational and Experimental Approaches for Using Molecular Engineering in the Design, Construction, and Analysis of Integrated Biosensor Microsystems. Fort Belvoir, VA: Defense Technical Information Center, August 2006. http://dx.doi.org/10.21236/ada455856.
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