Дисертації з теми "Biosensor label-free"
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Li, Bing. "Graphene transistors for label-free biosensing." Thesis, University of Plymouth, 2016. http://hdl.handle.net/10026.1/5291.
Повний текст джерелаNamhil, Zahra Ghobaei. "Nanogap capacitive biosensor for label-free aptamer-based protein detection." Thesis, University of Hull, 2018. http://hydra.hull.ac.uk/resources/hull:16463.
Повний текст джерелаStagni, degli Esposti Claudio <1977>. "Electronic biosensor arrays for label-free DNA and protein analysis." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2007. http://amsdottorato.unibo.it/408/1/Phd_thesis_ClaudioStagni.pdf.
Повний текст джерелаStagni, degli Esposti Claudio <1977>. "Electronic biosensor arrays for label-free DNA and protein analysis." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2007. http://amsdottorato.unibo.it/408/.
Повний текст джерелаZECCA, DAVIDE. "Label-free photonic crystal technology for immunosensing applications." Doctoral thesis, Politecnico di Torino, 2016. http://hdl.handle.net/11583/2645208.
Повний текст джерелаHo, M. Y. "An investigation of redox self-assembled monolayer in label-free biosensor application." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604101.
Повний текст джерелаMir, Llorente Mònica. "Oligonucleotide Based-Biosensors for Label-Free Electrochemical Protein and DNA Detection." Doctoral thesis, Universitat Rovira i Virgili, 2006. http://hdl.handle.net/10803/8542.
Повний текст джерелаDespite the great promise of DNA arrays in health care and their success in medical and biological research, the technology is still far away from the daily use in the clinic and even more far away from their implementation in home-diagnosis such as glucose biosensors.
Their principal problems are the high cost and difficulty of use, because it is required costly laboratory instruments and biology knowledge for the labelling of the DNA prior to the sample injection into the array.
On the other hand, the requirements that a biosensor should include are to be easy-to use so that it do not need the previous label of the sample and the addition of reagents. It should give a sensitive response in short time, and it should also include cheap generic multi-analyte detection.
The work carried out in this thesis describes new concepts of electrochemical biosensoric platforms based on oligonucleotides for detection of label-free DNA and protein, which include these requirements.
Preliminary experiments of direct DNA electrochemical detection of labelled ssDNA were performed to establish a protocol of DNA immobilisation, hybridisation and detection colourimetrically and electrochemically. DNA real samples and multi-analite detection on an array developed by biocopatible photolithography were used.
To avoid the analyte labelling to develop an easy to use and low cost device, a label-free electrochemical displacement of DNA sensor was described. The method of detection by displacement requires the pre-hybridisation of the capture probe immobilised on the electrode surface with a sub-optimum mutated oligonucleotide labelled with a redox molecule. Due to the higher affinity of the target that is fully complementary to the capture probe, the sub-optimum label can be displaced when the complementary target is introduced in the system. The decrease of the signal would verify the presence of the target and should be proportional to its concentration.
Sub-optimum hybridisation displacement detection was demonstrated colourimetrically and electrochemically with a sub-optimum mutated oligonucleotide labelled with horseradish peroxidase (HRP), and a ferrocene sub-optimum mutated oligonucleotide was also detected electrochemically, which do not required the addition of reagents for its detection.
Furthermore different strategies to develop an electrochemical oligonucleotide (aptamer) based sensor for reagentless and label-free protein detection was carried out. The most sensitive aptasensor achieved 30 fM of detection limit in just 5 minutes.
En els últims anys, els xips d'ADN han atret una atenció creixen en els camps de la diagnosis mèdica i la química analítica, degut a la seva portabilitat, sensibilitat, especificitat, ràpida resposta i l'ampli ventall d'aplicacions. Els xips d'ADN són rellevants per la diagnosis de malalties genètiques, detecció d'agents infecciosos, estudis de predisposició genètica, desenvolupament de medicina personalitzada, detecció d'expressió genètica diferencial, medicina forense, exploració de medicaments, seguretat alimentaria, defensa militar i monitorització mediambiental.
Encara que els xips basats en oligonucleòtids per la detecció d'ADN i proteïnes siguin una gran promesa en medicina i recerca biològica, aquesta tecnologia es encara molt lluny del seu ús diari en el camp clínic i encara més lluny de poder ser comercialitzada per ús domèstic com ho han estat el biosensors de glucosa.
Els seus principals problemes són el seu alt cost i la seva dificultat d'ús. Ja que per la seva utilització és necessari, previ a la injecció de l'analit en el biosensor, costosos instruments de laboratori i tècnics especialitzats en bioquímica pel marcatge i amplificació de les mostres d'ADN.
En canvi els requeriments que un biosensor ha d'incloure són, ser fàcil d'utilitzar, per tant que l'analit no necessiti un marcatge previ i l'addició de reactius per la seva detecció. Aquest ha de donar una resposta ràpida i sensible a baix cost i ha de permetre la detecció en el mateix equip de diferent tipus d'analits.
El treball fet en aquesta tesis descriu el desenvolupament de nous concepte de plataformes biosensòriques electroquímiques basades en oligonucleòtids per la detecció d'ADN i proteïnes no marcades prèviament, els quals inclouen aquest requeriments.
Experiments preliminars per la detecció de l'hibridació d'ADN marcat es van portar a fi per tal d'establir un protocol per la immobilització, hibridació i detecció d'ADN colorimètricament i electroquímicament. És van utilitzar mostres reals d'ADN i sistemes de detecció de multi-analits en un xip desenvolupat per fotolitografia biocompatible.
Per tal de no necessitar un marcatge previ de la mostres d'ADN i així simplificar i reduir el cost del futur biosensor es va desenvolupar un sistema electroquímic de desplaçament. El mètode lliure de marcatge es basa en el desplaçament de molècules d'oligonucleòtid mutat i marcat, els quals encara que continguin certes mutacions són capaços d'hibridar amb la sonda d'oligonucleòtid immobilitzat, però quan aquestes es troben en presència de l'analit desplaça la molècula mutada i marcada, disminuint així la senyal de manera proporcional en la concentració del analit. El sistema de desplaçament ha estat demostrat colorimètricament i electroquímicament utilitzant un marcatge d'HRP sobre el mutat i utilitzant un marcatge de ferrocè en l'oligonucleòtid mutat per tal de no necessitar afegir cap reactiu per la detecció de l'analit,
També es van portar a fi diferents estratègies per desenvolupar un biosensor electroquímic basat en oligonucleòtids (aptamers) per la detecció de la proteïna trombina sense el previ marcatge d'aquest analit i sense necessitat d'afegir reactius per la detecció del analit. En el sistema mes sensible es va obtenir un límit de detecció de 30 fM en un temps de resposta de sols 5 minuts.
En los últimos años, los chips de ADN han atraído una atención creciente diferentes campos, debido a su portabilidad, sensibilidad, especificidad y rápida respuesta. Los chips de ADN son aplicados en diagnosis de enfermedades genéticas, detección de agentes infecciosos, estudios de predisposición genética, desarrollo de medicina personalizada, detección de expresión genética diferencial, medicina forense, exploración de medicamentos, columnas de separación, seguridad alimentaría, defensa militar y monitorización medioambiental.
Aunque los chips basados en oligonucleótidos para la detección de ADN y proteínas tienen un gran futuro en diagnosis e investigación biológica, esta tecnología está aun muy lejos de su uso diario en el campo clínico y aun mas lejos de poder ser comercializado para uso doméstico como lo han sido los biosensores de glucosa.
Sus principales problemas son su alto coste y su dificultad de uso. Para su utilización es necesario, previo a la inyección del analito en el biosensor, costosos instrumentos de laboratorio y técnicos especializados en bioquímica para el marcaje y amplificación de las muestras de ADN.
En cambio los requerimientos que un biosensor ha de incluir son, ser fácil de utilizar, por tanto el analito no ha de necesitar un marcaje previo ni la adición de reactivos para su detección. Este ha de dar una respuesta rápida y sensible a bajo coste y ha de permitir la detección en el mismo equipo de diferentes analitos.
El trabajo hecho en esta tesis describe el desarrollo de nuevos conceptos de plataformas biosensóricas electroquímicas basadas en oligonucleótidos para la detección de ADN y proteínas no marcadas previamente, los cuales incluyen estos requerimientos.
Experimentos preliminares para la detección directa de la hibridación de ADN marcado se llevó a cabo para establecer protocolos para la inmovilización, hibridación y detección de ADN colorimétricamente y electroquímicamente. Se utilizaron muestras reales y sistemas de detección de multi-analitos en un chip desarrollado por fotolitografía biocompatible.
Para no necesitar un marcaje previo de la muestra de ADN y así simplificar y reducir el coste del futuro biosensor se desarrolló un sistema electroquímico de desplazamiento. El método libre de marcaje se basa en el desplazamiento de moléculas de oligonucleótido mutado y marcado, el cual aunque contenga ciertas mutaciones es capaz de hibridar con la sonda de oligonucleótido inmovilizado, pero cuando estas se encuentran en presencia del analito desplaza la molécula mutada, disminuyendo así la señal de manera proporcional a la concentración del analito. El sistema de desplazamiento ha sido demostrado colorimétricamente y electroquímicamente utilizando marcaje de HRP sobre el mutado, así como un marcaje de ferroceno que no requiere la adición de reactivos para su detección.
También se llevaron a cabo diferentes estrategias para desarrollar un biosensor electroquímico basado en oligonucleótidos (aptámeros) para la detección de trombina sin el previo marcaje de este analito, ni la adición de reactivos para la detección del analito. En el sistema más sensible se obtuvo un límite de detección de 30 fM en un tiempo de respuesta de solo 5 minutos
Wang, Yunmiao. "Microgap Structured Optical Sensor for Fast Label-free DNA Detection." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/32875.
Повний текст джерелаMaster of Science
CANTALE, Vera. "Towards label-free biosensors based on localized surface plasmon resonance." Doctoral thesis, Università degli studi di Ferrara, 2011. http://hdl.handle.net/11392/2388765.
Повний текст джерелаGarcía, Castelló Javier. "A Novel Approach to Label-Free Biosensors Based on Photonic Bandgap Structures." Doctoral thesis, Universitat Politècnica de València, 2014. http://hdl.handle.net/10251/35398.
Повний текст джерелаGarcía Castelló, J. (2014). A Novel Approach to Label-Free Biosensors Based on Photonic Bandgap Structures [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/35398
TESIS
GIOVANARDI, FABIO. "Fibre a nucleo cavo ad accoppiamento inibito per biosensori." Doctoral thesis, Università degli studi di Modena e Reggio Emilia, 2020. http://hdl.handle.net/11380/1200611.
Повний текст джерелаDuring the last decades, biosensors have gained more and more interest in several fields due to their particular features in the biochemical analysis. Involved sectors ranging from biomedical area to agri-food industry passing through defence and security. In the literature several types of biosensors have been studied based on different physical principle such as electrochemical, optical and mechanical (sensitive to mass changes). One of the main feature that the market requires is the “label-free” biosensing: the analysis is performed without any analytes alteration. The work described in this dissertation is focused on the conception and development of a new type of fiber based platform which could be a useful and effective for optical biosensing: Hollow core inhibited coupling fibers (HC-ICFs). They are characterized by a microstructured cladding composed of tubes that surround a hollow core. The holes running along HC-ICFs allow the infiltration of biological substances and for biological layers to attach on the air-dielectric interfaces. Compared to other holey fibers, the presence of a hollow core can further increase the infiltration feasibility and the sensor sensitivity. Moreover, in HC-ICFs the particular waveguiding mechanism, based on inhibition coupling, makes their transmission properties particularly sensitive to the thickness of the glass struts composing the microstructured cladding. Thank to that, if the molecular interactions between the surface of the glass struts and the target to be detected result in a generation of an additional layer which modifies the strut thickness, the target can easily detect by measuring the fiber transmission spectrum. The technique does not require any additional transducer component such as Bragg gratings, amplifying techniques such as nanoparticles, nor coherent sources. The principle is validated with experimental results showing the detection of molecules such as the streptavidin protein and DNA.
Sancho, Fornés Gabriel. "Integración de diferentes fenómenos fotónicos en tecnología de disco compacto para el desarrollo de biosensores label-free." Doctoral thesis, Universitat Politècnica de València, 2019. http://hdl.handle.net/10251/124819.
Повний текст джерела[CAT] En aquesta tesi s'ha abordat el desenvolupament de biosensors òptics label-free, basats en tecnologia de disc compacte, permetent així abaratir i simplificar la seua fabricació. El treball dut a terme ha consistit en estudiar diferents propietats fisicoquímiques desenvolupades per diversos materials. Això ha permès obtenir sistemes compactes i accessibles, capaços de sensar, amb bones prestacions analítiques, en diferents escenaris. En el capítol 1 es presenta un estudi d'inhibició enzimàtica sobre discos Blu-ray com a plataforma d'assaig per al cribratge de fàrmacs. Per a això, s'immobilitza de manera orientada una glicoenzima de la família de les peroxidases sobre la superfície del disc, i la seua activitat es relaciona amb els compostos a garbellar. Després d'assajar cada compost, es determina el grau d'inhibició enzimàtica mitjançant l'addició d'un substrat. La quantitat de producte obtingut, inversament proporcional al potencial inhibitori del compost en estudi, és quantificat amb un lector de discos que registra les variacions en la intensitat del làser reflectit degudes al producte enzimàtic. Això permet realitzar més de 1700 assajos simultanis en un únic disc Blu-ray el que mostra el seu potencial en anàlisi massiva d'alt rendiment. A més, es planteja una estratègia basada en hipersuperficies per a l'anàlisi de l'elevada quantitat de dades que es generen en les etapes del procés de descobriment de fàrmacs. En el capítol 2 s'aborda l'estudi d'una metodologia per reduir el soroll generat en la lectura de resultats obtinguts amb biosensors òptics, millorant així la seua sensibilitat. Per a això, es planteja l'estructuració de l'assaig en forma de franges en lloc del tradicional microarray, generant un senyal periòdic sinusoïdal en ser escanejades. En analitzar aquest senyal en domini de freqüències, aquesta es concentra en un pic a la freqüència de l'assaig, mentre que la major part del soroll apareix a freqüències molt més altes. Inicialment es volia reduir al màxim el soroll, per diferenciar les interaccions moleculars en format label-free. No obstant això, els assajos realitzats amb discos DVD no van generar prou senyal, havent de recórrer en aquesta ocasió al marcatge per a la quantificació d'immunoglobulines G i de caseïna. Malgrat això, la metodologia desenvolupada també es pot aplicar en biosensors tipus label-free, reduint el soroll i millorant la seua sensibilitat. El capítol 3 es centra en el desenvolupament de substrats interferometrics multicapa que varien la intensitat de la llum reflectida en realitzar un assaig analític en la seua superfície. Els substrats van ser fabricats utilitzant els materials que componen els DVD-RW, dipositats en capes de gruix controlat per tal d'obtenir la màxima resposta. Al seu torn, es van dissenyar de tal manera que un d'ells disminueixi la intensitat del feix reflectit com a resposta a les interaccions moleculars, mentre que l'altre l'augmenta. El treball inclou la utilització de principis i materials de la tecnologia de disc compacte per al desenvolupament del sistema de detecció. Per a això, es va utilitzar el capçal d'un lector de DVD, ja que disposa d'un làser i de tots els elements òptics necessaris per a l'escanejat vertical. Amb aquest sistema es quantifiquen amb èxit i sense marcatge immunoglobulines G i sulfasalazina, un macromolècula i un fàrmac de massa molecular reduïda. El capítol 4 consisteix en la fabricació d'un cristall fotònic utilitzant l'estructura dels discos compactes coberts amb una pel·lícula d'òxid de titani. S'han estudiat les propietats fisicoquímiques d'aquests substrats i s'han caracteritzat les propietats fotòniques. Tot això està en concordança amb els resultats obtingut mitjançant simulacions. Per interrogar els cristalls fotònics van ser necessaris una font de llum blanca i un espectrofotòmetre, a més dels elements òptics necessaris per guiar la llum.
[EN] In this thesis the development of label-free optical biosensors, based on compact disc technology, has been approached, thus making their manufacture cheaper and simpler. The work carried out has consisted of studying different physical-chemical properties manifested with several materials. This has allowed to obtain compact and accessible systems, capable of sensing with a great analytical performance in different scenarios. Chapter 1 presents an enzymatic inhibition study on Blu-ray discs as a test platform for drug screening. For this purpose, a glycoenzyme of the peroxidase family is immobilized on the surface of the disc whose activity is related to the compounds to be screened. After testing each compound, the degree of enzymatic inhibition is determined by adding the enzymatic substrate. The amount of product obtained is inversely proportional to the inhibitory potential of the compound, and is quantified with a disk reader that records the variations in the intensity of the reflected laser beam due to the enzymatic product. In addition, more than 1700 tests are performed on a single Blu-ray disc as proof of concept for application in high performance analysis and a hypersurface based strategy is proposed for the analysis of the large amount of data generated in the stages of the drug discovery process. Chapter 2 deals with the study of a methodology to reduce noise generated in the reading of results obtained with optical biosensors, hence improving their sensitivity. For this purpose, the structure of the test is proposed in the form of stripes instead of the traditional microarray, generating a sinusoidal periodic signal when they are scanned. When analysing this signal in frequency domain, it is concentrated in a peak at the frequency of the test, while most of the noise appears at much higher frequencies. Initially, the aim was to reduce noise as much as possible in order to differentiate molecular interactions in a label-free format. However, the tests carried out on a DVD did not generate enough signal, having to resort to labelling on this occasion for the quantification of immunoglobulins G and casein. Nevertheless, the methodology developed can be applied to label-free biosensors, reducing noise and improving sensitivity. Chapter 3 focuses on the development of multilayer interferometric substrates that vary the intensity of reflected light when performing an analytical test on their surface. The substrates were manufactured using the materials that make up the DVD-RW, deposited in layers of controlled thickness in order to obtain maximum response. At the same time, they were designed in such a way that one of them decreased the intensity of the reflected beam as a response to molecular interactions, while the other increased it. The work includes the use of principles and materials from compact disc technology for the development of the detection system. For this, the head of a DVD reader is used, as it has a laser and all the optical elements necessary for vertical scanning. With this system, immunoglobulins G and sulfasalazine, a macromolecule and a drug with reduced molecular mass are successfully quantified without labelling. Chapter 4 consists of the fabrication of a photonic crystal using the structure of the compact discs covered with a titanium oxide layer. The physical-chemical properties of these substrates have been studied and their photonic properties have been characterized. All this is in accordance with the results obtained through simulations. To interrogate the photonic crystals, a white light source and a spectrophotometer were needed, as well as the optical elements necessary to guide the light.
Sancho Fornés, G. (2019). Integración de diferentes fenómenos fotónicos en tecnología de disco compacto para el desarrollo de biosensores label-free [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/124819
TESIS
Faria, Henrique Antonio Mendonça. "Biossensores descartáveis de DNA para detecção dos vírus da zika e da dengue." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-05052017-094358/.
Повний текст джерелаAfter seventy years of its discovery, zika virus has emerged in Brazil, spread rapidly throughout the Americas, bringing unusual complications in diseases caused by flaviviruses, such as microcephaly. The World Health Organization classifies zika as the most harmful viral disease today and considers urgent the development of new diagnostic methods for zika and related diseases, such as dengue. Although there are tests to identify both infections, no current diagnostic method is rapid, specific and cost-efective. This thesis describes two types of electrochemical DNA biosensors for label-free detection of these zika and dengue. Disposable electrodes were fabricated on polyethylene terephthalate substrates covered with a nanometric gold layer by thermal evaporation, manufactured in one- and three-contact configurations. Genetic sequences of primers and complementary capture probes were designed based on the analysis of the virus genomes. The first biosensor we developed used the new electrode in an electrochemical cell and was able to identify zika or dengue DNA sequences. Analyses by electrochemical impedance spectroscopy showed that these biosensors are selective for zika or dengue with a detection limit of (9.86 ± 0.89) nmol L-1. A second type of biosensor used a three-contact electrode to identify DNA sequences in a drop of sample. In the central contact, used as a working electrode, the capture sequence was immobilized and the lateral contacts acted as reference and auxiliary electrodes. In this system the impedance measurements indicated a limit of detection of (25.0 ± 1.7) nmol L-1. The developed biosensors showed selectivity for zika and dengue in the synthetic DNA assays, and therefore are promising for the analysis of real samples, especially the polymerase chain reaction amplicon.
Wang, M. (Meng). "Polymer integrated Young interferometers for label-free biosensing applications." Doctoral thesis, Oulun yliopisto, 2012. http://urn.fi/urn:isbn:9789514299643.
Повний текст джерелаTiivistelmä Integroidulla optiikalla toteutetut anturit mahdollistavat biomolekulaarisen vuorovaikutuksen tutkimisen käyttäen herkkiä moniparametrisia ja merkkiaineettomia menetelmiä. Näiden bioantureiden valmistukseen käytetään tavallisesti CMOS-teknologian piiristä tuttuja epäorgaanisia puolijohteita ja eristemateriaaleja. Viime aikoina on kuitenkin polymeeristen materiaalien käyttöä integroidussa optiikassa tutkittu merkittävästi johtuen polymeerien hyvistä optisista ominaisuuksista, monipuolisesta työstettävyydestä ja edullisista kustannuksista. Tämän työn tarkoituksena on kehittää edullisia, kertakäyttöisiä, pääasiallisesti polymeerisistä materiaaleista valmistettuja bioantureita, jotka vastaavat suorituskyvyltään epäorgaanisista materiaaleista valmistettuja integroidun optiikan antureita. Tässä työssä kehitetyt polymeeriset integroidun optiikan bioanturit perustuvat Youngin interferometriin mahdollistaen ympäristökohinan kompensoinnin ja ne tuottavat pintavuorovaikutusten tutkimiseen jaksoittaisen interferenssikuvion. Työssä hyödynnettiin kolmea erilaista valokanavarakennetta huomioiden niiden käytön helppous, valmistuksen yksinkertaisuus ja mittausherkkyys. Yksi kehitetyistä polymeerisistä bioantureista koostui päällekkäisistä kerrostetuista polymeerikerroksista. Toisen tutkitun rakenteen toiminta puolestaan perustui käänteiseen harjannevalokanavaan. Mittausherkkyyttä parannettiin pinnoittamalla polymeerirakenne Ta2O5-pinnoitteella. Näin muodostui kerrostettu komposiittivalokanava, joka oli tässä työssä tutkittu kolmas sensorirakenne. Itse bioanturien lisäksi kehitettiin myös valmistusprosessi, jossa hyödynnettiin UV-painatusta ja nestefaasipinnoitusta. Tässä työssä havaittiin lisäksi, että kehitetty yksinkertainen valmistusmenetelmä on paitsi toimiva, myös mahdollisesti siirrettävissä rullalta rullalle valmistus- ja tuotantoteknologiaan. Kehitettyjen anturien kalibrointi suoritettiin homogeenisella taitekerroinmittauksella käyttäen liuoksia, jotka valmistettiin glukoosista ja deionisoidusta vedestä. Kehitettyjen anturien soveltuvuus spesifien molekyylien tunnistamista varten todennettiin tutkimalla vasta-aineiden ja antigeenien sitoutumisreaktioita ja vuorovaikutusta C-reaktiivisella proteiinilla ja sen konjugaateilla. Lisäksi työssä tutkittiin veden absorption vaikutusta mittauksen stabiilisuuteen. Tutkimuksessa suoritettiin vertailu kehitettyjen anturien ja niiden ominaisuuksien välillä kiinnittäen huomiota mittausherkkyyteen, stabiilisuuteen, määritys- ja toteamisrajoihin ja muihin anturien valmistukseen sekä käyttöön liittyviin keskeisiin piirteisiin. Tulokset osoittavat, että Ta2O5-pinnoitetun polymeerivalokanavan mittausherkkyys oli suurin vertailluista rakenteista. Homogeenisessä taitekerroinmittauksessa saavutettu määritys- ja toteamisraja oli 9×10-7 taitekerroinyksikköä (RIU). Pintamassatiheysmittauksessa saavuttu tulos oli 270 fg/mm2
Han, Yinhua. "Label-free detection of biomolecules by a field effect transistor microarray biosensor with bio-functionalized gate surfaces." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=982123027.
Повний текст джерелаMohammed, Kader Hamno. "Development of a label-free biosensor method for the identification of sticky compounds which disturb GPCR-assays." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-220645.
Повний текст джерелаGuo, Xuefei. "Development of Electrochemical Sensors for Biodegradable Metallic Implants and Development of a Label-free Biosensor for Bacteria." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1342106824.
Повний текст джерелаNajeeb, Najla. "Design, fabrication and evaluation of a label-free silicon-on-insulator 'Lab on a Chip' optical biosensor." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/45421/.
Повний текст джерелаGonzález, Guerrero Ana Belén. "Bimodal waveguide interferometer device based on silicon photonics technology for label-free and high sensitive biosensing." Doctoral thesis, Universitat Autònoma de Barcelona, 2012. http://hdl.handle.net/10803/107886.
Повний текст джерелаOptical biosensor devices based on evanescent wave detection could overcome the limitations of conventional diagnostic tests (expensive and time-consuming) due to the possibility of carrying out the detection in real-time and using a label-free scheme. Among the different optical transducers, interferometric devices have evidenced the best limit of detection (LOD) for refractive index changes of bulk solutions (10-7-10-8 Refractive Index Units, RIU) and for surface sensing (in the pg/ml range) and a wider linear range. However, usual interferometric transducers (Mach-Zehnder or Young interferometers) employ the Y-junction to split or recombine light, a drawback for the coherence and performance of the device due to standard tolerances of microfabrication techniques. To overcome these problems, we have developed a simple configuration based on a single straight waveguide where two modes of the light of the same polarization are interfering between them. This simple approach avoids the complexity of the usual interferometric transducers and as a consequence, more reliable and reproducible biosensors can be obtained. This thesis is focused on the development and characterization of a new photonic transducer, the Bimodal Waveguide device (BiMW), for label- free and high sensitive biosensing. To achieve this, the following steps have been pursued: 1. Design, fabrication, and optical characterization of an optical transducer operating by two-mode interference principle. 2. Development and optimization of biofunctionalization strategies on the transducer surface using silanization techniques. 3. Study of the applicability of the biosensor with the demonstration of bioanalytical diagnosis of relevant problems. The transducers are fabricated at wafer level in Clean Room facilities, which warrants a cost-effective and mass-production of the sensor chips. The device is highly sensitive to small changes in the refractive index occurring on the sensor area, leading to a detection limit of 2.5×10-7 RIU for bulk changes in refractive index solutions. The biofunctionalization of the sensor area is one of the most crucial aspects of this work. Optimized functionalization procedures have been achieved, which has been employed to immobilize different types of bioreceptors (DNA strands, proteins, and antibodies) on the surface. The optimized protocols have been used for the demonstration of different bioapplications such as the detection of hormones, bacteria, or complementary DNA sequences. The results presented in this work have highlighted the superior performance of this device in comparison with conventional diagnostics tests due to: i) the possibility of monitoring biomolecular interactions in real-time and by using a label-free scheme which reduce the time and cost of the assay , ii) the fabrication of the device using standard silicon microelectronics technology opening the possibility for mass-production, iii) the high sensitivity demonstrated for the different bioapplications assessed achieving detection limits in the pg/ml range (femtomolar), and iv) the device meets the specific requirements to be miniaturized and integrated in a multiplexed platform. This work opens the door for the integration of this transducer in a lab-on-a-chip device, including the in-coupling/out-coupling of light, a system able to modulate the interferometric signal, and the incorporation of microfluidics channels for multiplexing. Each of these subjects adds a great complexity to the final device, and must be independently developed and optimized in order to be successfully integrated at the final lab-on-a-chip biosensor. Finally, the possibility to detect simultaneously multiple analytes will involve further efforts in developing new optical in and outcoupling as well as new biofunctionalization strategies.
Khosravi, Farhad. "Carbon nanotubes micro-arrays: characterization and application in biosensing of free proteins and label-free capture of breast cancer cells." Digital WPI, 2016. https://digitalcommons.wpi.edu/etd-dissertations/347.
Повний текст джерелаWang, Xingwei. "Label-free DNA Sequence Detection Using Oligonucleotide Functionalized Fiber Probe with a Miniature Protrusion." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/28662.
Повний текст джерелаPh. D.
Cansiz, Sena. "Development Of A Sandwich-type Dna Array Platform For The Detection Of Label-free Oligonucleotide Targets." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612658/index.pdf.
Повний текст джерелаheat immobilization and immobilization via a heterobifunctional cross-linker (HBCL). In regard to the experiments, it is observed that using a cross-linker instead of heat immobilization reduces the ratio of false negative control results in a significant manner. Following the solid support and immobilization method choice comparative optimization studies which include cross-linker type, probe concentration, sensitivity of the platform and hybridization conditions (sequence, temperature and duration) were conducted. Optimum hybridization signal was obtained with a 32.5
Liu, Chen. "Advanced optical fibre grating sensors for biochemical applications." Thesis, Bangor University, 2019. https://research.bangor.ac.uk/portal/en/theses/advanced-optical-fibre-grating-sensors-for-biochemical-applications(29757d94-bfe1-4d75-a4db-8563be1a056f).html.
Повний текст джерелаMOI, VALERIA. "Development and Optimization of a Label-free Optical Biosensor Based on Bloch Surface Waves Sustained by One Dimensional Photonic Crystals." Doctoral thesis, Politecnico di Torino, 2015. http://hdl.handle.net/11583/2593366.
Повний текст джерелаbhardwaj, vinay. "Label-free surface-enhanced Raman spectroscopy-linked immunosensor assay (SLISA) for environmental surveillance." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/2321.
Повний текст джерелаCastagna, Riccardo. "Detection of Angiogenic Growth Factor by Microcantilever Biosensors." Doctoral thesis, Università degli studi di Trieste, 2011. http://hdl.handle.net/10077/4578.
Повний текст джерелаTo reach new and relevant insights in biomolecular sciences, new tools for fine and precise measurement are needed. Nowadays advances in the field of micro-electro-mechanical systems (MEMS) offer unique opportunities in the design of ultrasensitive analytical devices to support the molecular sensing investigations. Among them Microcantilever (MC) biosensors are label-free platforms that combine a biologically sensitive with a physical transducer in order to selectively and quantitatively detect the presence of specific compounds in a given external environment. Since they can be operated either as nanomechanical resonator or as surface stress sensor, MCs - activated with DNA probes or antibodies for molecular recognition - enable the measurement of mass with extraordinary sensitivity. In particular, the development of mass detector biosensor based on MC systems would permit to shift from qualitative data to quantitative measurements of key molecules involved in physiological processes. This can lead crucial informations to characterize complex mechanisms such as angiogenesis and tumor progression and to the quantification of small amounts of cancer markers, such as Angiopoietin-1 (ANG-1), and their modulation during the early stages of tumor development.
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VANJUR, LUKA. "KINETICS OF NUCLEIC ACIDS HYBRIDIZATION AND OF COMPLEX DNA STRUCTURES FORMATION ON A BIOSENSING SURFACE." Doctoral thesis, Università degli Studi di Milano, 2021. http://hdl.handle.net/2434/806961.
Повний текст джерелаGhasemi, Farshid. "Multiplexed label-free integrated photonic biosensors." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53633.
Повний текст джерелаGandolfi, Davide. "On-chip photonic label-free biosensors." Doctoral thesis, Università degli studi di Trento, 2015. https://hdl.handle.net/11572/368219.
Повний текст джерелаGandolfi, Davide. "On-chip photonic label-free biosensors." Doctoral thesis, University of Trento, 2015. http://eprints-phd.biblio.unitn.it/1452/1/Tesi_PhD_Gandolfi_Davide.pdf.
Повний текст джерелаDong, Jianchun. "Label free electronic detection of biomarkers /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/5893.
Повний текст джерелаGylfason, Kristinn Björgvin. "Integrated Optical Slot-Waveguide Ring Resonator Sensor Arrays for Lab-on-Chip Applications." Doctoral thesis, KTH, Mikrosystemteknik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-12214.
Повний текст джерелаQc20100715
SABIO
Dar, T. "Numerical characterisation of label free optical biosensors." Thesis, City University London, 2015. http://openaccess.city.ac.uk/13075/.
Повний текст джерелаZaccari, Irene. "Multiplexed label-free electronic biosensors for clinical diagnostics." Thesis, University of Leeds, 2013. http://etheses.whiterose.ac.uk/6893/.
Повний текст джерелаThompson, Liz. "A label free DNA hybridization sensor." Thesis, Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/26968.
Повний текст джерелаBrandigampala, Savindra Madhavi. "Label-free electrical immunoassay biosensors for early disease diagnosis." Thesis, Wichita State University, 2012. http://hdl.handle.net/10057/5378.
Повний текст джерелаThesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical Engineering and Computer Science
Martínez, Pérez Paula. "Development and Optimization of Experimental Biosensing Protocols Using Porous Optical Transducers." Doctoral thesis, Universitat Politècnica de València, 2021. http://hdl.handle.net/10251/172541.
Повний текст джерела[CA] Els biosensors són dispositius analítics amb aplicabilitat en diferents camps i amb nombrosos avantatges enfront d'altres mètodes analítics convencionals, com són l'ús de xicotets volums de mostra i reactius, la seua sensibilitat i la seua ràpida resposta, sense necessitat de pretractament de la mostra, equips cars o personal especialitzat. No obstant això, es tracta d'un camp d'investigació relativament nou en el qual encara queda molt camí per fer. Aquesta Tesi doctoral pretén aportar el seu òbol a aquest camp de coneixement mitjançant l'estudi del potencial de diferents materials porosos com a transductors per al desenvolupament de biosensors òptics amb resposta en temps real i sense marcatges. Els materials proposats van des d'aquells artificialment sintetitzats, com a silici porós (SiP), nanofibras (NFs) polimèriques o membranes polimèriques comercials, fins a materials naturals amb propietats fotòniques que encara no havien sigut explotades per al sensat, com són els exoesquelets de biosílice de diatomees. Tots ells tenen en comú la simplicitat en la seua obtenció, evitant costosos i laboriosos processos de nanofabricació. Per al seu estudi, s'analitzarà la seua resposta òptica i, en aquells casos en els quals aquesta permeta dur a terme experiments de detecció, es desenvoluparan estratègies per a la seua biofuncionalizació i la seua implementació en experiments de biosensat. En el cas del SiP i les NFs s'han optimitzat els paràmetres de fabricació per a obtenir una resposta òptica adequada que permeta la seua interrogació. A continuació, s'ha dut a terme la seua biofuncionalizació emprant mètodes covalents i no covalents, així com diferents bioreceptors (aptàmers d'ADN i anticossos) per a estudiar el seu potencial i les seues limitacions com a biosensors. En el cas de les membranes comercials i l'exoesquelet de sílice de diatomees, s'ha caracteritzat la seua resposta òptica i s'han dut a terme experiments de sensat d'índex de refracció per a estudiar la seua sensibilitat. Així mateix, s'ha desenvolupat un mètode de funcionalizació de la superfície de l'exoesquelet de diatomees basat en l'ús de polielectròlits catiònics. Com a resultat, s'ha demostrat el potencial tant de NFs per al desenvolupament de biosensors, com el de membranes comercials per a sensors amb una aplicació que no requerisca una elevada sensibilitat però sí un baix cost. A més, s'ha posat de manifest el gran potencial de l'exoesquelet de diatomees per al desenvolupament de sensors basats en la seua resposta òptica. Per contra, les limitacions trobades en el desenvolupament de biosensors basats en SiP han evidenciat la necessitat d'un estudi rigorós i l'optimització de l'estructura dels materials porosos prèviament a ser usats en (bio)sensat.
[EN] Biosensors are analytical devices with application in diverse fields and with several advantages relative to other conventional methods, such as the use of small volumes of sample and reagents, their sensitivity and their fast response, without the need of the sample pretreatment, expensive equipments or specialised technicians. Nevertheless, this is a relatively new research field in which there is a long way to go yet. This doctoral Thesis aims at doing its bit to this field of knowledge by studying the potential of different porous materials as transducers for the development of real-time and label-free optical biosensors. The proposed materials range from those artificially synthesised, such as porous silicon (pSi), polymeric nanofibres (NFs) or commercial polymeric membranes, to natural materials with photonic properties that had not been exploited for sensing yet, such as biosilica exoskeletons of diatoms. All of them have in common its simple production, avoiding expensive and laborious nanofabrication processes. For their study, their optical response will be analysed and, in those cases in which such optical response allows performing detection experiments, strategies for their biofunctionalisation and their implementation in biosensing experiments will be developed as well. Regarding pSi and NFs, the fabrication parameters were optimised to get a suitable optical response for their interrogation. Afterwards, their surface functionalisation was carried out by covalent and non-covalent methods, as well as different bioreceptors (DNA aptamers and antibodies), to study their potential and their constraints as biosensors. Concerning commercial membranes and the biosilica exoskeleton of diatoms, their optical response was characterised and refractive index sensing experiments were carried out to study their sensitivity. Additionally, a biofunctionalisation method for the surface of the diatoms exoskeleton was developed based on the use of cationic polyelectrolytes. As a result, it was demonstrated the potential of NFs for the development of biosensors, as well as the potential of commercial membranes for developing sensors for an application that does not require a high sensitivity but a low cost. Furthermore, the great potential of biosilica exoskeleton of diatoms for the development of sensors based on their optical response has been revealed. By contrast, the constraints found in the development of pSi illustrate the importance of an accurate study and optimisation of porous materials structure before using them for (bio)sensing.
Martínez Pérez, P. (2021). Development and Optimization of Experimental Biosensing Protocols Using Porous Optical Transducers [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/172541
TESIS
Para, Prashanthi. "FABRICATION OF NANOSTRUCTURES FOR IMPROVED PERFORMANCE OF ELECTROCHEMICAL SENSORS AND FOR REFERENCE COMPENSATION IN LOCALIZED SURFACE PLASMON RESONANCE SENSORS." UKnowledge, 2009. http://uknowledge.uky.edu/gradschool_theses/130.
Повний текст джерелаSalazar, Soto Arnoldo. "Conception d'un imageur CMOS à colonne active pour un biocapteur optique SPR." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENT063/document.
Повний текст джерелаThis dissertation presents the design and implementation of a CMOS imager for use in integrated biosensors based on Surface Plasmon Resonance. First, the optimal conditions for plasmon resonance in a CMOS/Post-CMOS compatible interface are obtained by COMSOL modelling. Second, a 32x32-pixel CMOS-Active Column Sensor (CMOS-ACS) is implemented on 0.35 um CMOS technology. In a gold-water interface with prism excitation, it is found that for prisms showing refractive indexes of 1.55 and 1.46, optimal plasmon coupling is obtained for gold films with thicknesses of 50 and 45 nm respectively. Under these conditions, approximately 99.19% and 99.99% of the incident light's energy is transferred to the surface plasmon for both prism respectively, provided that the incident light, with a wavelength of 633 nm, arrives with incidence angles of 68.45° and 79.05° respectively. It is also obtained that a change of 10-4 RIU in the refractive index of the dielectric medium, produces a change of 0.01° in the plasmon resonance angle, which under a light intensity modulation scheme produces a change of 0.08% in the reflected light's energy reaching the photodetector. Concerning the CMOS imager, a n-well/p-substrate photodiode is selected as the photosensing element, due to its low junction capacitance, which results in high efficiency and high conversion gain compared to the n-diff/p-substrate photodiode. Computer simulations with Cadence and Silvaco produced a junction capacitance of 31 fF and 135 fF respectively. The imager's pixel is based on a three-transistor (3T) configuration and shows a fill factor of 61%. The readout circuitry employs an Active Column Sensor (ACS) technique to reduce the Fixed Pattern Noise (FPN) associated with traditional Active Pixel Sensors (APS). Additionally, Non-Correlated Double Sampling (NCDS) and Delta Double Sampling (DDS) are used as noise reduction techniques. An experimental optical setup is used to characterize the performance of the imager, obtaining a conversion gain of 7.3 uV/e-, a photodiode junction capacitance of 21.9 fF, a read noise of 324.5 uV, equivalent to ~45 e- and a dynamic range of 50.5 dB. The benefits of ACS and NCDS-DDS are observed in the low pixel and column FPN of 0.09% and 0.06% respectively. The work presented in this thesis is a first step towards the goal of developing a fully integrated SPR-biosensing platform incorporating light source, SPR interface, microfluidic channel, optical elements and CMOS imager
Lanfranco, R. "OPTICAL DETECTION OF MOLECULAR INTERACTIONS ON THE SURFACE OF MATERIALS INDEX-MATCHED TO WATER." Doctoral thesis, Università degli Studi di Milano, 2015. http://hdl.handle.net/2434/378031.
Повний текст джерелаAhn, Sunmin. "Performance improvement of label-free biosensors and their applications in DNA and protein microarrays." Thesis, Boston University, 2013. https://hdl.handle.net/2144/12706.
Повний текст джерелаMicroarray technologies have provided powerful tools in modem biotechnology to decipher the complex interconnectivity of genetic and regulatory network. Label-free biosensors have emerged as competitive technologies because they offer more economic and simple procedures, allow molecular interactions in their native state, and provide interaction kinetics, compared to the traditional luminescence-based sensors. While these advantages enable better understandings of the intricate biomolecular interactions, label-free biosensors have yet to be widely adapted in biological and medical research. We present two approaches to develop successful, high-throughput, label-free biosensors by using Interferometric Reflectance Imaging Sensor (IRIS). First, we offer strategies to improve the performance of label-free biosensors by increasing sensitivity and accuracy. Sensitivity enhancement is achieved by utilizing mass tags. Accuracy improvement is accomplished through extensive characterization of stability of DNA and protein microarrays. Following stability characterization of the surface chemistry, the substrate, and the immobilized biomolecules, microarray fabrication methods and normalization techniques are developed to reduce error, hence, increasing the accuracy of quantitative analysis. The degradations of the sensor surface that we discover from stability characterization are susceptible to other label-free biosensors. Thus, the correction strategies that we present can be utilized for accurate quantitative analysis of a variety of label-free biosensors. Second, we develop four applications for IRIS. 1) We present applications for quantitative gene expression analysis and disease screening using DNA microarrays by demonstrating quantitative analysis of DNA hybridization and successful detection of single nucleotide polymorphism. 2) We present an application for quantitative analysis of transcription factors using ssDNA and dsDNA microarrays. We discover a new binding motif for TATA-binding protein and propose alternative models for eukaryotic transcription initiation. 3) We present an application to study immune response using antibody microarrays by demonstrating dynamic detection interleukin-6 with ~ ng/mL sensitivity and successfully detecting the small macromolecule in biologically complex fluid. 4) We propose an application to investigate cellular response to external stimuli, such as drugs, toxins, and pathogens, using patterned cell-protein microarrays. We present strategies of fabricating cell-protein microarrays and demonstrate interleukin-8 detection with ~ pg/mL sensitivity using gold nanoparticles. Improved performance and diverse biological applications of IRIS will help successful implementations of high-throughput label-free biosensors in healthcare.
Zaffino, Rosa Letizia. "Development of a nano sensor for direct-electric free-label detection of DNA’s hybridization and single nucleotide polymorphism." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/384708.
Повний текст джерелаLa detección de hibridación de cadenas de ADN es un reto relevante científicamente y tecnológicamente, que puede aprovechar de las posibilidades proporcionadas por los alcances en los procesos de nano fabricación y caracterización, inspiradores de la idea de una medicina en el punto de atención. El propósito de este trabajo es de establecer un sistema de detección de hibridación de ADN, y polimorfismo de un solo nucleótido (SNP), basado en la medida eléctrica de la reasistencia de un nano-gap funcional izado con el ADN diana. El desarrollo y test del sistema se ha llevado a cabo fijando diferentes objetivos. Un estudio preliminar de la literatura relacionada con las propiedades eléctricas del ADN se ha conducido con la finalidad de establecer el marco de factibilidad del proyecto. De acuerdo con los resultados de este estudio ha sido posible idear el sistema y optimizar su eficacia respeto a las experiencias reportadas. Fijar una estrategia de fabricación de los dispositivos capaz de proveer nano-gaps aptos a la medida de conductividad muy baja, según una rutina de fácil implementación y con alta reproducibilidad de los resultados. Estos se han caracterizados mediante el utilizo de diferentes técnicas basadas primariamente en métodos de detección Óptica y Eléctrica/Electro-química. Obtener la bio-funcionalización selectiva de los electrodos en el nano-gap testando y caracterizando métodos diferentes. Probar el principio de funcionamiento del sistema a través de la medida de la conductividad en los nano-gap durante las diferentes etapas de funcionalización con los bio-receptores y el DNA target. Optimizar el sensor testando su selectividad respeto a la presencia de mutaciones, la sensibilidad a medir diferentes concentraciones del target, y finalmente la posibilidad de regeneración del dispositivo después desnaturalización del ADN hibridado
Afonin, Kirill A. "Design and characterization of novel bio-sensor platform for sequence specific, label-free, fluorescent detection of native RNA molecules." Bowling Green, Ohio : Bowling Green State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=bgsu1206395144.
Повний текст джерелаCombs, Zachary Allen. "Advanced substrate design for label-free detection of trace organic and biological molecules." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50314.
Повний текст джерелаAfonin, Kirill A. "Design and Characterization of Novel Bio-Sensor Platform for Sequence Specific, Label-Free, Fluorescent Detection of Native RNA Moledcules." Bowling Green State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1206395144.
Повний текст джерелаBronder, Thomas Stefan [Verfasser], and Michael J. [Akademischer Betreuer] Schöning. "Label-free detection of tuberculosis DNA with capacitive field-effect biosensors / Thomas Stefan Bronder ; Betreuer: Michael J. Schöning." Marburg : Philipps-Universität Marburg, 2021. http://d-nb.info/1226287395/34.
Повний текст джерелаNguyen, Thanh Chien [Verfasser], Andreas [Akademischer Betreuer] König, and Sven [Akademischer Betreuer] Ingebrandt. "Readout Concepts for Label-Free Biomolecule Detection with Advanced ISFET and Silicon Nanowire Biosensors / Thanh Chien Nguyen ; Andreas König, Sven Ingebrandt." Kaiserslautern : Technische Universität Kaiserslautern, 2018. http://d-nb.info/1154765415/34.
Повний текст джерелаEstrada, Leypón Oscar Emilio. "Micro-Nano-Bio Systems for on-line monitoring of in vitro biofilm responses." Doctoral thesis, Universitat Ramon Llull, 2015. http://hdl.handle.net/10803/300595.
Повний текст джерелаEl trabajo presentado en esta tesis doctoral tiene como principal objetivo la contribución en el campo de la microbiología para entender los biofilms y el posible control de desarrollo mediante el uso de métodos y enfoque multidisciplinar. Los biofilms están definidos como comunidades de microorganismos que crecen embebidos en una matriz exopolisacárida y se adhieren a una superficie inerte o tejido vivo. La formación de los biofilms bacterianos tiene un gran interés en microbiología clínica debido al desarrollo de infecciones que son causadas por contacto directo o por colonización de dispositivos médicos implantados y prótesis. Actualmente se consideran la causa de más del 60 % de las infecciones bacterianas. El problema de los biofilms bacterianos a nivel clínico es que muestran mejor resistencia a antibióticos llegando incluso a ser de 500 a 5000 veces más resistentes a agentes antimicrobianos comparado a la misma bacteria planctónica (bacteria en suspensión). Ha habido muchas tentativas de adaptar métodos a laboratorios clínicos donde se reproducen las condiciones para el desarrollo de biofilms, pero aún no se ha llegado a obtener óptimos protocolos estándar para este propósito de monitorizar la formación y toxicidad en tiempo real. Ha crecido el interés en diseño, desarrollo y utilización de dispositivos de microfluídica que puedan emular los fenómenos biológicos que ocurren con diferentes geometrías, dinámica de fluidos y restricciones de transporte de biomasa en microambientes fisiológicos. La investigación descrita en esta tesis se lleva a cabo con diferentes métodos “label-free” basados en variación acústica y/o propiedades eléctricas para la monitorización de biofilms. El trabajo presentado en esta monografía describe un dispositivo “custom-made” para la utilización de Espectroscopia de impedancia electroquímica como herramienta útil para obtener información de adherencia y formación de biofilms. El hecho de añadir nanopartículas como segundo biosensor permite la correlación de biofilm con su toxicidad en tiempo real para la detección del punto óptimo del tratamiento de biofilms. Finalmente el diseño de esta tecnología es usada para el ensayo de la respuesta de biofilms a antibióticos como modelo in vitro de infecciones causadas por biofilms.
The work presented in this thesis has the main aim to contribute in the field of clinical microbiology to understand the biofilms and the possible of development through the use of methods with multidisciplinary approach. Biofilms are defined as communities of microorganisms that grow embedded in a matrix of exopolysaccharides and adhering to an inert surface or living tissue. The formation of bacterial biofilms has an interest in clinical microbiology with the development of infections that usually arise from either direct contact or the colonization of implanted medical devices and prostheses. Currently they are considered the cause of over 60% of bacterial infections. The problem of bacterial biofilms at clinical level is showing great resistance to antibiotics, so that the biofilm bacteria are 500 to 5000 times more resistant to antimicrobial agents that the same bacteria grown in planktonic cultures (bacteria in suspension). There have been attempts to adapt methods to clinical laboratories where they reproduce the conditions of biofilms, but have not yet adopted an optimal standard protocol for this purpose to follow-up the formation and toxicity in real-time. There has been a growing interest in design, development and utilization of microfluidic devices that can emulate biological phenomena that occur in different geometries, fluid dynamics and mass transport restrictions in physiological microenvironments. The research described in this thesis deals with different label-free methods based on variation of acoustic and electric properties for biofilm monitoring. The work presented in this monograph describe a custom-made device for using electrochemical impedance spectroscopy (EIS) as useful tool to obtain information of adherence and formation of biofilms. The addition of nanoparticles as toxicity biomarker allows the correlation of biofilm formation with its toxicity in real-time for detention of the optimal point for biofilm treatment. Finally the design of this technology is used for testing the biofilm response to antibiotic as in vitro model of biofilm-related infection.
Gao, Shiuan-Huei, and 高炫揮. "Label-free and real-time protein biosensor." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/70401169843752291048.
Повний текст джерелаLiu, Wen-Hsing, and 劉紋杏. "Label-free and real-time electrical biosensor." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/97539236198040691241.
Повний текст джерела