Este trabalho descreve a preparação, a caracterização e o uso de um biossensor de pasta de carbono modificado com a enzima acetilcolinesterase para a quantificação de carbamatos em alimentos, bem como o estudo das constantes de velocidade para a reação enzima/substrato (iodeto de acetiltiocolina) em solução. Inicialmente foram realizados testes de estabilidade, tanto para o substrato quanto para a enzima. Nestes testes, a absorção na região do UV-vis do substrato não apresentou diminuição significativa em 11 dias de análises, já a enzima apresentou uma grande perda de sua atividade com apenas três dias de preparo da solução. Na preparação do eletrodo de trabalho alguns parâmetros foram otimizados, tais como: quantidade de enzima e de ftalocianina de cobalto (CoPC) no eletrodo, bem como a porcentagem de glutaraldeído utilizada. A melhor resposta ocorreu para adição de 2,40x10-3g de enzima, 0,90x10-3g de CoPC (referentes à massa de 0,017g de pasta de carbono) e solução de glutaraldeido 1%. A seguir, realizou-se um experimento baseado na inibição da atividade da enzima, causada pela imersão do eletrodo na solução contendo o pesticida carbaril nas concentrações 5,00x10-5 e 1,00x10-4 mol L-1. Notou-se que, com o aumento da concentração do carbaril, houve aumento na inibição da atividade enzimática. Desta forma o eletrodo apresentou-se apto para determinação analítica de pesticidas. Estas medidas foram realizadas em meio de tampão fosfato 0,1 mol L-1, pH 7,4 e com tempo de incubação para o carbaril, metomil e aldicarbe foram de 8, 12 e 15 minutos, respectivamente. Os limites de detecção (LD) e quantificação (LQ) obtidos utilizando-se o biossensor amperométrico para o carbaril foram de 2,00x10-6 mol L-1 (0,40 mg L-1) e 6,70 x 10-6 mol L-1 (1,30 mg L-1), para o metomil de 1,88 x 10-7mol L-1 (30,45 micro g L-1) e 6,26 x 10-7 mol L-1 (0,10 mg / L-1) e para o aldicarbe de 1,10x10-6 mol L-1 (0,20 mg L-1) e 3,60x10-6 mol L-1 (0,70 mg L-1). Para a formulação comercial Lannate (metomil) os LD e LQ foram 2,13x10-7 mol L-1 (34,50 micro g L-1) e 7,09x10-7 mol L-1(0,12 mg L-1), respectivamente. As medidas de HPLC apresentaram LD e LQ de 1,58 x 10-8 mol L-1 (3,18 micro g L-1) e 5,27x10-8 mol L-1 (10,60 micro g L-1) para o carbaril e de 9,02 x 10-10 mol L-1 (0,15 micro g L-1) e 3,00 x 10-9 mol L-1 (48,60 micro g L-1) para o metomil. Testes de recuperação foram realizados usando ambas as técnicas para o carbaril e Lannate. As recuperações utilizando-se o biossensor mostraram-se eficientes, variando de 76,83 a 106,67% para o carbaril e de 78,00 a 96,50% para a Lannate, enquanto que nas medidas de HPLC, as recuperações foram de 78,00 a 108,33% para o carbaril e de 57,00 a 99,50% para o Lannate. A recuperação para o aldicarbe no tomate foi de 62,40 %. As análises da enzima em solução mostraram que a metodologia empregada neste estudo é adequada para a determinação das constantes de velocidade para a etapa lenta da reação AchE/AchI. Observou-se que os valores destas constantes são dependentes da concentração dos pesticidas fenitrothion (organofosforado) e carbaril (carbamato), em baixa concentração ambos apresentaram constantes de velocidade similares, mas com o aumento dessa concentração, o fenitrothion apresentou menor constante de velocidade em relação ao carbaril, sugerindo que este apresenta maior inibição da enzima e por conseqüência maior toxicidade no organismo. Esses resultados mostraram uma possível metodologia analítica para a quantificação destes pesticidas, obtendo-se os valores das constantes de velocidade enzimática e suas dependências com as concentrações dos pesticidas em solução. / This work describes the development, characterization and utilization of a carbon paste biosensor based in the acetylcholinesterase enzyme for carbamates determinations in foodstuff, as well as the study of rate constants for enzyme/substrate reaction in solution. Stability tests were initially performed for both the substrate and the enzyme. In these tests, the signal for UV-vis adsorption for the substrate shows no inhibition during 11 days while for the enzyme it has been demonstrated that a considerable loss of activity occurs after three days from the solution preparation. In the electrode preparation, some experimental parameters were optimized, such as the amount of enzyme and the content of cobalt ftalocyanine (CoPC) in the electrode, as well as the employed percentage of glutaraldehide. The highest analytical signals were obtained for the addition of 2.40x10-3 g enzyme, 0.90x10-3 g CoPC (related to the massa of 0,017g of carbon paste) and a 1% glutaraldehide solution. The next step was to carry out an experiment based in the inhibition of enzyme activity by the pesticide. For this, the biosensor was immersed in 5.00x10-5 e 1.00x10-4 mol L-1 carbaryl solutions. It was observed that, by increasing the carbaryl concentration, the electrochemical signal of the sensor was inhibited proportionally. This was indicative that the sensor was adequate to be used in carbaryl monitoring and analytical determinations. The analytical determinations of carbamate pesticides were performed in 0.1 mol L-1 phosphate buffer, pH 7,4, with incubation time of 8, 12 and 15 minutes for carbaryl, metomil and aldicarb, respectively. The detection (LD) and quantification (LQ) limits obtained with the biosensor were 2.00x10-6 mol L-1 (0.40 mg L-1) and 6.70 x 10-6 mol L-1 (1.30 mg L-1) for carbaryl, 1.88x10-7mol L-1 (30.45 micro g L-1) and 6.26x10-7 mol L-1 (0.10 mg / L-1) for metomil and 1.10x10-6 mol L-1 (0.20 mg L-1) and 3.60x10-6 mol L-1 (0.70 mg L-1) for aldicarb. For the commercial formulation of metomil, Lannate, LD and LQ obtained were 2.13x10-7 mol L-1 (34.50 microg L-1) and 7.09x10-7 mol L-1(0.12 mg L-1), respectively. The HPLC measurements showed LD and LQ of 1.58x10-8 mol L-1 (3.18micro g L-1) and 5.27x10-8 mol L-1 (10.60 micro g L-1) for carbaryl and 9.02x10-10 mol L-1 (0.15 micro g L-1) and 3.00x10-9 mol L-1 (48.60 micro g L-1) for metomil. Recovering tests were also done with both analytical techniques for carbaryl and Lannate. The obtained recoveries using the biosensor were in the range of 76.83 to 106.67% for carbaryl and 78.00 to 96.50% for Lannate, while using the HPLC, the recoverings were 78.00 a 108.33% for carbaryl and 57.00 to 99.50% for Lannate. The recovering of aldicarb in tomatoes, with HPLC, were 62.40 %. The study of the enzymatic reaction in solution showed that the employed methodology allows to obtain the rate constant values for the rate determining step of the AchE/AchI reaction. It was observed that these rate constant values were strongly dependent in the pesticide concentrations for fenitrothion (organofosforous) and carbaryl (carbamate). At low concentration levels of the pesticide in the electrolyte, all the rate constants showed similar values but, when the pesticide concentration was raised, fenitrothion was found to exert a more powerful inhibition action for the enzyme activity than carbaryl, thus suggesting its higher toxic character. These results showed the development of a possible analytical methodology for quantification of these pesticides, by calculating the rate constant value and its dependence to the pesticide concentration in solution.

A combination of magnetic sensors with magnetic nanoparticles offers a promising approach for highly sensitive, simple, and rapid detection of cancer cells and biomolecules. The challenge facing the field of magnetic biosensing is the development of low-cost devices capable of superconducting quantum interference device (SQUID)-like field sensitivity at room temperature. In another area of interest, improving the sensitivity of existing electromagnetic field sensors for microwave energy sensing applications is an important and challenging task. In this dissertation, we have explored the excellent magnetoimpedance and microwave absorption responses of soft ferromagnetic amorphous ribbons and microwires for the development of high-performance magnetic biodetectors and microwave energy sensors. We have developed the effective approaches to improve the magnetoimpedance response of Co65Fe4Ni2Si15B14 amorphous ribbons by tuning their dimension and/or coating them with thin layers of CoFe2O4. Coating amorphous and crystalline CoFe2O4 films on the ribbon surface have opposite impacts on the magnetoimpedance response. Pulsed laser deposition (PLD) is shown to be a novel in-situ annealing and coating method for improving the magnetoimpedance response of the soft ferromagnetic amorphous ribbons for advanced sensor applications. The magnetoimpedance responses are also enhanced in multi-microwire systems relative to their single microwires. We have introduced a new method of combining the magnetoresistance (MR), magnetoreactance (MX), and magnetoimpedance (MI) effects of a soft ferromagnetic amorphous ribbon to develop an integrated biosensor with enhanced sensitivity and tunable frequency. While existing MI biosensors have limited sensitivities, we show that by exploiting the MR and MX effects it is possible to improve the sensitivity of the biosensor by up to 50% and 100%, respectively. The MX-based approach shows the most sensitive detection of superparamagnetic (Fe3O4) nanoparticles at low concentrations, demonstrating a sensitivity level comparable to that of a SQUID-based biosensor. Unlike a SQUID, however, the proposed MX technique is cryogen-free and operates at room temperature, providing a promising avenue to the development of low-cost highly sensitive biosensors. We have further improved the detection sensitivity of the MI and MX biosensors by patterning the sensing (ribbon) surface with nano/micro-sized holes, using the etching or focused ion beam (FIB) technique. These biosensors have been successfully employed to detect and quantify various bioanalytes, such as Curcumin-type anticancer drugs, bovine serum albumen (BSA) proteins, and Lewis lung carcinoma (LLC) cancer cells that have taken up the surface-functionalized Fe3O4 nanoparticles. Since Fe3O4 nanoparticles are widely used as magnetic resonance imaging (MRI) contrast agents, our biosensing technique can also be used as a new, low-cost, fast and easy pre-detection method before MRI. Finally, we have developed a new method of using a soft ferromagnetic glass-coated amorphous microwire as a microwave absorber for fabrication of a fiber Bragg grating-based microwave energy sensor with improved sensitivity and less perturbation of the microwave field. As compared to a similar approach that uses gold to absorb electromagnetic radiation, the microwire yields a device with greater sensitivity (~10 times at f = 3.25 GHz) relative to the perturbation of the microwave field. A correlation between the magnetic softness and microwave absorption in the microwires has been established, paving the way to improve the performance of the microwave energy sensor by tailoring their soft magnetic properties.

Surface acoustic waves (SAWs) have a large number of applications and the majority of them are in the sensor and actuator fields targeted to satisfy market needs. Recently, researchers have focused on optimizing and improving device functions, sensitivity, power consumption, etc. However, SAW actuators and sensors still cannot replace their conventional counterparts in some mechanical and biomedical areas, such as actuators for liquid pumping under microfluidic channels and sensors for real-time cell culture monitoring. The two objectives of this dissertation are to explore the potential of piezoelectric materials and surface acoustic waves for research on actuators and sensors in the mechanical pump and biosensor areas. Manipulation of liquids in microfluidic channels is important for many mechanical, chemical and biomedical applications. In this dissertation, we first introduced a novel integrated surface acoustic wave based pump for liquid delivery and precise manipulation within a microchannel. The device employed a hydrophobic surface coating (Cytop) in the device design to decrease the friction force and increase the bonding. Contrary to previous surface acoustic wave based pumps which were mostly based on the filling and sucking process, we demonstrated long distance media delivery (up to 8mm) and a high pumping velocity, which increased the device’s application space and mass production potential. Additionally, the device design didn’t need precise layers of water and glass between substrate and channel, which simplified the design significantly. In this study, we conducted extensive parametric studies to quantify the effects of the liquid volume pumped, microchannel size, and input applied power as well as the existence of hydrophobic surface coating on the pumping velocity and pump performance. Our results indicated that the pumping velocity for a constant liquid volume with the same applied input power could be increased by over 130% (2.31 mm/min vs 0.99 mm/min) by employing a hydrophobic surface coating (Cytop) in a thinner microchannel (250 µm vs 500 µm) design. This device could be used in circulation, dosing, metering and drug delivery applications which necessitated small-scale precise liquid control and delivery. This dissertation also introduced a novel SAW-based sensor designed and employed for detecting changes in cell concentration. Before conducting cell concentration experiments, preliminary experiments were conducted on weight concentration differentiation of microfluidic particles based on a polydimethylsiloxane (PDMS) channel and surface acoustic wave resonator design. The results confirmed that our device exerted an ultra-stable status to detect liquid properties by monitoring continuous fluids. An improved design was carried out by depositing a 200 nm ZnO layer on top of the lithium tantalate substrate surface increased the sensitivity and enabled cell concentration detection in a microfluidic system. Comprehensive studies on cell viability were carried out to investigate the effect of shear horizontal (SH) SAWs on both a cancerous (A549 lung adenocarcinoma) and a non-cancerous (RAW264.7 macrophage) cell line. Two pairs of resonators consisting of interdigital transducers (IDTs) and reflecting fingers were used to quantify mass loading by the cells in suspension media as well as within a 3-dimensional cell culture model. In order to predict the characteristics and optimize the design of the SH-SAW biosensor, a 3D COMSOL model was built to simulate the mass loading response of the cell suspensions. These results were compared to experimental data generated by pipetting cell concentrations of 3.125K, 6.25K 12.5K, 25K and 50K cells per 100µL into the PDMS well and measuring to obtain the relative frequency shift from the two oscillatory circuit systems (one of which functioned as a control). Frequency shift measurements were also collected from A549 cells cultured on a 3D nanofiber scaffold produced by electrospinning to evaluate the device’s ability to detect changes in cell density as the cells proliferated in culture over the course of eight days. The device’s ability to detect changes in cell density over time in a 3D model along with its biocompatibility reveal great potential for this device to be incorporated into 3D in vitro cancer research applications.

Botrytis species affect over 300 host plants in all climate areas of the world, at both pre and post-harvest stages, leading to significant losses in agricultural produce. Therefore, the development of a rapid, sensitive and reliable method to assess the pathogen load of infected crops can help to prescribe an effective curing regime. Growers would then have the ability to predict and manage the full storage potential of their crops and thus provide an effective disease control and reduce post-harvest losses. A highly sensitive electrochemical immunosensor based on a screen-printed gold electrode (SPGE) with onboard carbon counter and silver / silver chloride (Ag/AgCl) pseudo-reference electrode was developed in this work for the detection and quantification of Botrytis species. The sensor utilised a direct sandwich enzyme-linked immunosorbent assay (ELISA) format with a monoclonal antibody against Botrytis immobilised on the gold working electrode. Two immobilisation strategies were investigated for the capture antibody, and these included adsorption and covalent immobilisation after self-assembled monolayer formation with 3-dithiodipropionic acid (DTDPA). A polyclonal antibody conjugated to the electroactive enzyme horseradish peroxidase (HRP) was then applied for signal generation. Electrochemical measurements were conducted using 3,3’, 5,5’-tetramethylbenzidine dihydrochloride / hydrogen peroxide (TMB/H2O2) as the enzyme substrate system at a potential of -200 mV. The developed biosensor was capable of detecting latent Botrytis infections 24 h post inoculation with a linear range from 150 to 0.05 μg fungal mycelium ml-1 and a limit of detection (LOD) as low as 16 ng ml-1 for covalent immobilisation and 58 ng ml-1 for adsorption, respectively. Benchmarked against the commercially available Botrytis ELISA kits, the optimised immuno-electrochemical biosensor showed strong correlation of the quantified samples (R2=0.998) ... [cont.].

De senaste decennierna har en miniatyriseringstrend inom ingenjörsvetenskaperna blivit allt större. Komplexa maskiner eller processer skalas ner till en allt mindre skala. Det kan vara motorer som inte är större än 500 μm eller kemiska analyser som vanligtvis görs på en större laboratorieutrustning som nu går att utföra på en yta på ca 2x4 cm. En sådan utrustning som kan utföra kemiska analyser kallas ofta för ”Lab-on-a-Chip” (LoC) och innehåller kemiska kretsar som hanterar mikroflöden av analysvätskor. En del av dagens forskning för att ta fram nya LoC handlar om att möta ett behov av portabel, billig och snabb analysutrustning i utvecklingsländer. Dock finns ett problem med att få ut produkter på marknaden. De flesta LoC som presenteras i forskningsrapporter idag är tillverkade av polydimetylsiloxan (PDMS). Det är en elastomer som lämpar sig väl för småskalig prototypframställning, men är svår att producera i stor skala, dessutom krävs ofta extern utrustning för att vätskeflöde skall uppstå. Det finns även LoC i papper, vilkas porösa struktur möjliggör för spontan vätsketransport, wicking, utan extern utrustning. Dessa är billiga och har nått större framgång. Exempelvis är vanliga graviditetstest som går att köpa på apoteket ofta LoC i papper. Textiliers fukt- och vätskehantering är relevant för komfort, och för många beredningsprocesser. Exempelvis är wicking ett välstuderat område som det finns djup kunskap om i den textila sektorn. Denna kunskap kan utnyttjas för att skapa ett textilt LoC. Att använda textila tekniker innebär möjligheter att styra vätskeflödet med hjälp av garn med och utan wickingförmåga. Denna studie undersöker hur en vävs naturliga X-Y-system av varp- och väftgarner kan utnyttjas för att skapa en kontrollerad vätskestyrning, en textil kemisk krets. Arbetet har utgått från frågan om hur en väv kan konstrueras för att leda en vätska från ett varpgarn till ett väftgarn utan läckage i oönskad del av väven. Två olika garner valdes: ett monofilament av polyeten för de områden där vätskeledning ej var önskvärd och ett multifilament av Coolmax® polyester med god wickingförmåga där vätskan vara avsedd att transporteras. Tre parametrar testades; bindningen i de delar av väven som var avsedd för vätsketransport (önskad väg); bindningen där vätskan skulle övergå från ett varpgarn till ett väftgarn (vägskälet); och antalet wickande trådar (trådigheten). Åtta olika kombinationer avseende dessa parametrar testade. Samtliga parametrar hade signifikant inverkan på läckaget. Den konstruktion med minst läckage in i oönskad väg var den med bindning över två trådar i önskad väg, flotteringar i vägskälet och var tvåtrådig. Den framtagna vävens möjlighet att användas i en biosensor undersöktes genom ett försök att konstruera en elektrokemisk glukosmätare. Som elektroder valdes en silverbelagd polyamid. Vid preparering av elektroderna skedde en oväntad reaktion mellan det silverbelagda garnet och en av de ingående kemikalierna, prussian blue. Därför kunde ingen detektion av glukos ske. Det noterades även att den textila kemiska kretsens wickingförmåga försämrades då den utsattes för våta prepareringsprocesserna av elektroderna. Från experimentet med att konstruera en textil glukosmätare drogs slutsatsen att preparering av elektroderna bör ske innan invävning i den textila kemiska kretsen.

This thesis report works on optically characterizing waveguide based biosensors consisting of thin, narrow Au stripes embedded in CYTOP. The devices were examined using an ever evolving and improving interrogation setup, variations of which are described in detail in this document. A number of changes were made to the setup configuration in order to reduce noise levels and increase efficiency and accuracy of acquired measurements. Waveguides of varying configurations (straight waveguides and Mach-Zehnder Interferometers with etched and cladded channels) are described and optically characterized. The characterization results of these devices are presented in this thesis. Bulk index measurements are carried out in order to determine a suitable bio-sensing solution with a refractive index matched to that of CYTOP. Step index measurements clearly distinguishing the introduction of sensing solutions of refractive indices varying from one another, are made available. Preliminary bio-sensing experiments involving detection of change in refractive index of sensing fluid as well as adlayer thickness with the introduction of analytes binding to the waveguide surface that has been functionalized with antibodies, using both straight and cladded waveguides with single mode outputs are studied.

Sclerotinia sclerotiorum, a fungal pathogen of over 400 plant species has been estimated to cost UK based farmers approximately £20 million per year during severe outbreak (Oerke and Dehne 2004). S. sclerotiorum disease incidence is difficult to predict as outbreaks are often sporadic. Ascospores released from the fruiting bodies or apothecia can be dispersed for tens of kilometres. This makes disease control problematic and with no S. sclerotiorum resistant varieties available, growers are forced to spray fungicides up to three times per flowering season in anticipation of the arrival of this devastating disease. This thesis reports the development of the first infield S. sclerotiorum biosensor which aims to enable rapid detection of airborne ascospores, promoting a more accurate disease risk assessment and fungicide spraying regime. The sensor is designed to detect the presence of oxalic acid, the main pathogenicity factor secreted during early S. sclerotiorum ascospore germination. Upon electrochemical detection of this analyte in the biosensor, a binary output is relayed to farmer to warm him of a disease risk. This project focused on the development of a nutrient matrix which was designed to be contained within the biosensor. The role of this matrix was to promote the growth of captured airborne S. sclerotiorum ascospores and induce high levels of oxalic acid secretion. The use of the designed biological matrix to promote oxalic acid production was tested during three field trials in S. sclerotiorum artificially inoculated fields. This thesis describes the use of contemporary pathogenomics technologies to further investigate candidate genes involved in pathogenicity alongside the secretion of oxalic acid. A pre-described bioinformatics pipeline was used to predict the S. sclerotiorum secretome to identify potential effector proteins as well as explore proteins which are unique to S. sclerotiorum to be used as other novel targets for detection. GFP tagged constructs were designed to investigate the expression of the putative targets for S. sclerotiorum detection. The transcriptomes of wild type and oxalic acid deficient S. sclerotiorum strains during infection as well as during a saprotrophic stage were investigated. This study provided expression support for not only some of the unannotated genes identified in the putative secretome, but some candidate genes speculated to be involved in infection.

With a rising demand for low cost solutions to healthcare services, analysis, and toxicology, the Integrated Biosensor Platform developed by Acreo Swedish ICT and Linköping University, fills the gap where conventional sensors are not suitable. This report focuses the update of hardware and software in order to increase stability, introduce new sensors, and allow for wireless communication through NFC. Positive result and increased stability is presented, when measuring with a stable reference potential. The potential of NFC is shown in a breadboard setup and problems when printing an antenna is elaborated in terms of coil turns and size. An ethanol sensor is introduced to the platform and discussion manly focuses on characterization of the sensor. A potentiometric setup is also tested with low results and the problems of the current platform as a potentiometric sensor is discussed. From the collective results and a broader look at society is the justification of the platform existence evaluated. The need for the platform, especially as a mean to solve health problems in development countries, is argued to justify the environmental footprint of a disposable platform. / Med en ökad efterfrågan på tjänster inom hälsovård, analys, och toxikologi är målet för Integrated Biosensor Platform från Acreo Swedish ICT och Linköpings Universitet, att fylla gapet där konventionella sensorer inte är brukliga. Den här rapporten fokuserar på uppdateringen av hård och mjukvara för att öka stabiliteten, introduktionen av nya sensorer samt möjligheten till trådlös kommunikation genom NFC. Positiva resultat och ökad stabilitet presenteras med introduktionen av en stabil referens spänning. NFC och dess möjligheter testas i utvecklingsmiljö och problem diskuteras i samband med tryckta antenner utifrån storlek och design. En ethanolsensor inkluderas till plattformen och resultatet utvärderas främst från användningsområden och karaktärisering av sensorn. En potentiometrisk konfiguration av plattformen testas med lågt resultat och problemen med den nuvarande plattformen som potentiometrisk sensor presenteras. En samlad utvärdering av plattformens existensberättigande görs från både resultat som rapporten presenterat och en omvärldsanalys. Behovet av plattformen är, framför allt som en lösning till hälsovård i utvecklingsländer, ansett att rättfärdiga dess negativa miljöpåverkan som en "engångssensor".

Surface Plasmon Resonance (SPR) and localized surface plasmon resonance (LSPR) biosensors have brought a revolutionary change to in vitro study of biological and biochemical processes due to its ability to measure extremely small changes in surface refractive index (RI), binding equilibrium and kinetics. Strategies based on LSPR have been employed to enhance the sensitivity for a variety of applications, such as diagnosis of diseases, environmental analysis, food safety, and chemical threat detection. In LSPR spectroscopy, absorption and scattering of light are greatly enhanced at frequencies that excite the LSPR, resulting in a characteristic extinction spectrum that depends on the RI of the surrounding medium. Compositional and conformational change within the surrounding medium near the sensing surface could therefore be detected as shifts in the extinction spectrum. This dissertation specifically focuses on the development and evaluation of highly sensitive LSPR biosensors for in situ study of biomolecular binding process by incorporating nanotechnology. Compared to traditional methods for biomolecular binding studies, LSPR-based biosensors offer real-time, label free detection. First, we modified the gold sensing surface of LSPR-based biosensors using nanomaterials such as gold nanoparticles (AuNPs) and polymer to enhance surface absorption and sensitivity. The performance of this type of biosensors was evaluated on the application of small heavy metal molecule binding affinity study. This biosensor exhibited ~7 fold sensitivity enhancement and binding kinetics measurement capability comparing to traditional biosensors. Second, a miniaturized cell culture system was integrated into the LSPR-based biosensor system for the purpose of real-time biomarker signaling pathway studies and drug efficacy studies with living cells. To the best of our knowledge, this is the first LSPR-based sensing platform with the capability of living cell studies. We demonstrated the living cell measurement ability by studying the VEGF signaling pathway in living SKOV-3 cells. Results have shown that the VEGF secretion level from SKOV-3 cells is 0.0137 ± 0.0012 pg per cell. Moreover, we have demonstrated bevacizumab drug regulation to the VEGF signaling pathway using this biosensor. This sensing platform could potentially help studying biomolecular binding kinetics which elucidates the underlying mechanisms of biotransportation and drug delivery.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第23066号 / 医博第4693号 / 新制||医||1049(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 渡邊 直樹, 教授 溝脇 尚志, 教授 藤田 恭之 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM