In the field of chemical and biological sensors, the increased need for better sensitivity, faster response and higher selectivity during an analysis process, requires the development of more and more efficient transducing sensing layers. In this context, and with the aim to detect small non-electroactive molecules, such as atrazine (ATZ), we designed, characterized and developed sensing layers constituted by functionalized Molecularly Imprinted Conducting Polymers (MICP) and we integrated them into electrochemical and gravimetrical sensors. Starting from acetonitrile pre-polymerization media containing ATZ as template molecules in the presence of thiophene-based functional monomers (FM, namely TMA, TAA, EDOT, TMeOH or Th), differently functionalized and structurally different polythiophene-based FM-MICP films were electrosynthesized onto gold substrates and used for ATZ detection. The sensing properties of FM-MICP layers were shown to result from the presence in their backbones of pre-shaped FM-functionalized imprinted cavities which keep the memory of the targets. Nevertheless, non-specific adsorption onto the surface of the sensing layers takes place systematically, which affects the selectivity of the recognition process. Thanks to surface characterization techniques, we highlighted the influence of the thickness and of the structural properties of the layers on the efficiency of the recognition process. Besides, this latter was shown to operate in the bulk of the polymer matrixes thanks to layers porosity. On another hand, electrochemical measurements correlated with semi-empirical calculations demonstrated the influence of the nature of FM on the strength of the ATZ-FM interaction in the pre-polymerization medium, and then on the number of ATZ molecular imprints and on the sensitivity towards ATZ of the FM-MICP layers. We showed that TAA-MICP, which presents a low limit of detection (10-9 mol L-1) and a large dynamic range (10-8 to 10-4 mol L-1), is the best sensing layer since it offers the best compromise between high level of specific detection of ATZ and low level of non-specific adsorption. Finally, TAA-MICP was used as sensitive layer in an original Electrochemical Surface Acoustic Wave sensor (ESAW) which enabled simultaneous coupled gravimetric and electrochemical measurements.

L'industrie cosmétique a un recours croissant aux espèces végétales comme sources de principesactifs naturels. Leur extraction nécessite des supports sélectifs tels que les polymères à empreintesmoléculaires (MIP). Les travaux de cette thèse reposent sur le développement de MIP pourl’extraction sélective de la glucosamine, de la fructosazine et de la 2,5-déoxyfructosazine.Dans une première partie, trois approches ont été développées pour extraire la glucosamine par desMIP : l’approche covalente, semi-covalente et non covalente. Pour chacune, les différents paramètresintervenant dans la synthèse des MIP ont été optimisés. Les meilleurs résultats ont été obtenus avecun MIP synthétisé selon une approche non covalente ionique reposant sur la complexation de laglucosamine par un acide sulfonique. Les performances du MIP se sont avérées supérieures à cellesde supports commerciaux et des extractions à partir de végétaux ont été réalisées. Le potentielindustrialisable du MIP a été validé lors de premiers tests à plus grande échelle.Dans une deuxième partie, l’extraction simultanée de la fructosazine et de la 2,5-déoxyfructosazine aété réalisée suite au développement d’un MIP synthétisé selon une approche covalente reposant surla formation d’esters boroniques. Une méthode de synthèse originale est exposée puisque lestemplates ont été formés in situ lors de la polymérisation. Le MIP obtenu s’est avéré sélectif dechaque composé et a permis de purifier et de séparer la fructosazine et la 2,5-déoxyfructosazine dematrices végétales et alimentaires.Tous ces travaux ont été réalisés dans une démarche éco-responsable s’appuyant sur l’emploi desolvants aqueux lors de la polymérisation et de l’extraction. / The cosmetic industry uses plants as sources of natural active ingredients. The extraction of theseactive ingredients requires selective extraction method such as molecularly imprinted polymers (MIP)technique. This thesis describes the development of MIP for the selective extraction of glucosamine,fructosazine and 2,5-déoxyfructosazine.In the first part, three approaches were developed to extract glucosamine by MIP technique: thecovalent approach, semi-covalent and noncovalent. For each approach, the various parametersinvolved in the synthesis of the MIP were optimized. The best results were obtained with a MIPsynthesized with a non-covalent ionic approach based on the complexation of glucosamine by asulfonic acid. The MIP exhibits higher performance than commercial media and extractions fromplants were performed. The potential for industrialization of the MIP was validated during initial testson a larger scale.In the second part, the simultaneous extraction of fructosazine and 2,5-déoxyfructosazine wasperformed following the development of a MIP synthesized using a covalent approach based on theformation of boronic esters. An original synthesis method is exposed since the templates were formedin situ during the polymerization. The MIP obtained showed good selectivity for each compound andallowed to separate and purify fructosazine and 2,5-déoxyfructosazine from plant and food matrices.All these works were performed according to an eco-friendly approach based on the use of aqueoussolvents as solvents for polymerization and extraction.

Ce mémoire présente une exploration des polymères à empreintes moléculaires (MIP) comme outils d’une libération contrôlée de bioactifs olfactifs ou pour le criblage/préselection de composés à activité antivirales ou anti-tumorales sur le site actif d’une enzyme. La première partie est une étude de la complexation de la vanilline sur des billes polymériques sphériques en vue d’une libération contrôlée (pH, salinité, …). Ces études portent sur les caractéristiques de l'absorption et la libération de la molécule d'intérêt dans le milieu aqueux sur les microsphères fonctionnalisées fourni par Merck ESTAPOR® Microsphères. Nous avons ensuite synthétisé divers MIP de vanilline au format monolithique. Plusieurs stratégies d’impression ont été étudiées: non covalente, covalente et semi-covalente. La composition du MIP préparé dans chaque approche a été optimisée pour obtenir les meilleures propriétés et performances. L'affinité, la sélectivité et la capacité du MIP ont été déterminées. Les MIPs ont été évalués par extraction en phase solide (SPE) d'analogues structuraux de la vanilline dans des échantillons naturels (extrait de vanille, vin). La deuxième partie de ce mémoire concerne l’évaluation de MIPs de l’adénosine 5’-monophosphate (AMP) Le polymère a été préparé par une approche non-covalente et son efficacité de recapture a été caractérisée par analyse frontale (FA). L’analyse frontale est une technique qui permet de discriminer des interactions spécifiques des non spécifiques et de comprendre les mécanismes de liaison dans des cavités spécifiques. / This thesis report presents the exploration of molecularly imprinted polymers (MIP) for the application in controlled release and targeting antivirus and anticancer drugs. The first part of this study describes the imprinting of vanillin as a monolith. Several strategies were studied: non-covalent, covalent and semi-covalent. The composition of the MIP prepared in each approach was optimized to obtain the best properties and performance. The affinity, selectivity and capacity of MIP were determined. MIPs were evaluated in solid-phase extraction (SPE) of structural analogues in natural samples (vanilla extract, wine). We also present the study of the exploration of spherical beads as potential tools for the controlled release of vanillin. These studies concern the characteristics of uptake and release of the molecule of interest in the aqueous medium on functionalised microspheres supplied by Merck ESTAPOR Microspheres®. The second part of this thesis is devoted to studies on the evaluation of MIP of adenosine 5'-monophosphate (AMP). The polymer was prepared in non-covalent approach and efficiency of binding was characterised using frontal analysis (FA). FA is a useful technique that allows discriminate specific and nonspecific interactions and to understand the binding mechanisms in specific cavities.

Submitted by THIAGO DE MORAIS MARIANO null (thiaguitobatera@gmail.com) on 2016-03-24T18:46:42Z No. of bitstreams: 1 DISSERTAÇÃO-VERSÃO FINAL.pdf: 1116395 bytes, checksum: 647c9edcd2f39b64fa625d689d79f620 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-03-24T19:59:05Z (GMT) No. of bitstreams: 1 mariano_tm_me_araiq.pdf: 1116395 bytes, checksum: 647c9edcd2f39b64fa625d689d79f620 (MD5) / Made available in DSpace on 2016-03-24T19:59:05Z (GMT). No. of bitstreams: 1 mariano_tm_me_araiq.pdf: 1116395 bytes, checksum: 647c9edcd2f39b64fa625d689d79f620 (MD5) Previous issue date: 2016-03-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O óleo fúsel é o co-produto da destilação do etanol e é formado pela mistura de álcoois superiores (álcoois com mais de 3 carbonos), ésteres, aldeídos, entre outros. O volume de óleo fúsel produzido em média é 2,5 L de óleo fúsel por 1000 L de etanol, sendo utilizado como combustível nas caldeiras das usinas, bem como precursores de ésteres utilizados em indústrias de cosméticos e em fabricação de plásticos. O presente trabalho teve como objetivo desenvolver um sensor eletroquimico (GCE/RGO/AuNP/MIP) baseado em polímeros molecularmente impressos (MIP), utilizando o pirrol (Py) como monômero, contendo nanopartículas de ouro (AuNP) e óxido de grafeno reduzido (RGO) para a determinação do álcool isoamílico, um dos componentes do óleo fusel. Foram realizados estudos eletroquímicos, como estudo de velocidade de varredura, para determinar reversibilidade do sistema e diagnosticar o controle do processo eletródico. Após os estudos eletroquímicos, foram realizadas caracterização morfológica por Microscopia Eletrônica de Varredura com Canhão de Emissão de Eletrons com efeito de campo (MEV-FEG) e caracterização eletroquimica por Espectroscopia de Impedancia Eletroquímica (EIS). Após a caracterização, foi avaliada a performance analítica do sensor GCE/RGO/AuNP/MIP, utilizando um intervalo de concentração de 1,0×10-7 até 1,0×10-4 mol L-1, encontrando um limite de detecção de 8,2×10-8 mol L-1. Foi determinada a concentração de álcool isoamílico em amostra de óleo fúsel pelo método de adição de padrão e o valor encontrado foi de 1,6×10-4 mol L-1. O método foi validado através de ensaio de recuperação, mostrando que o sensor desenvolvido é promissor para a utilização em determinação de álcool isoamílico em óleo fúsel. / The fusel oil is co-product of the distillation of ethanol and is formed by the mixture of higher alcohols (alcohols having more than 3 carbons) esters, aldehydes, etc. The volume of fusel oil produced on average is 2.5 L fusel oil by 1000 L of ethanol, used as fuel in the boilers of the plants, as well as esters of precursors used in the cosmetics and plastics manufacturing. This study aimed to develop an electrochemical sensor (GCE/RGO/AuNP/MIP) based on molecularly imprinted polymers (MIP), using pyrrole (Py) as the monomer, containing gold nanoparticles (AUNP) and reduced graphene oxide (RGO) for determining the isoamyl alcohol, one of fusel oil components. They were conducted electrochemical studies, such as study of scanning speed, to determine system reversibility and diagnose the control of the electrode process. After the electrochemical studies were conducted morphological caractrização by Scanning Electron Microscopy with Electrons Emission Cannon with field effect (SEM-FEG) and electrochemical characterization by spectroscopy Electrochemical Impedance (EIS). After the characterization, the analytical performance of the GCE/RGO/AuNP/MIP sensor was evaluated using a concentration range of 1.0×10-7 to 1.0×10-4 mol L-1, encountering a detection limit 8.2×10-8 mol L-1. Was determined the concentration of isoamyl alcohol in a sample of fusel oil by standard addition method and the value found was 1.6×10-4 mol L-1. The method was validated by recovery test, showing that the sensor is designed promising for use in determining isoamyl alcohol fusel oil.

Orientadora: Profa Dra Elizabete Campos de Lima / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Ciência e Tecnologia Ambiental, 2017. / Nos efluentes, estão presentes as mais variadas misturas de fármacos, produtos de limpeza, de higiene, derivados de processos industriais, entre outros. Mesmo após o tratamento, estudos indicam que esses compostos podem continuar presentes, sendo despejados nos corpos hídricos, representando riscos para o ecossistema aquático, os quais só se tornam conhecidos após estudos científicos. Dentre essas substâncias, os fármacos são grandes representantes e a fluoxetina é um antidepressivo massivamente utilizado, capaz de promover alterações comportamentais em espécies aquáticas expostas a mesma concentração em que essa substância é encontrada em matrizes ambientais. Para controle de compostos considerados potencialmente nocivos ao ecossistema e à saúde humana, é indispensável conhecer suas concentrações em efluentes e corpos d'água. Contudo, esse tipo de matriz contém impurezas e compostos que não são de interesse, necessitando preparo de amostra para limpeza e pré-concentração do analito alvo. Nesse contexto, o objetivo deste trabalho foi desenvolver um polímero de impressão molecular para extração em fase sólida como preparo de amostra para determinação de fluoxetina em efluentes por cromatografia líquida acoplada a detector de arranjo de diodos, HPLC-DAD. Foram sintetizados polímeros de impressão molecular com ácido acrílico, ácido metacrílico e estireno como monômeros funcionais. Os rendimentos de síntese foram de 67,2% para estireno, 64,0% para ácido acrílico e 62,2% para ácido metacrílico. Foi avaliada a seletividade entre cafeína e fluoxetina, resultando em melhor afinidade do polímero com o antidepressivo. A adsorção ocorre como reação de pseudo segunda ordem, com melhor adsorção do polímero impresso do que o polímero não impresso. Ao aplicar a extração em fase sólida em efluente e analisá-lo pelo método HPLC-DAD desenvolvido e validado, o valor de recuperação do polímero molecularmente impresso (30,6%), apesar de estar abaixo do desejado, se mostrou bastante superior ao valor de recuperação do cartucho comercial C18 (2,1%). / In the sewage, there are the most varied mixtures of medicines, cleaning products, hygiene products, industrial processes derivatives, among others. Even after treatment, studies indicate that these compounds may remain in wastewater, being discharged into the water bodies, representing risks to the aquatic ecosystem, risks which only become known after scientific studies. Among these substances, the pharmaceuticals are great representatives and fluoxetine is a massively used antidepressant, capable of promoting behavioral changes in aquatic species exposed to the same concentration in which this substance is found in environmental matrices. For control of compounds considered potentially harmful to the ecosystem and to human health, it is indispensable to know their concentrations in effluents and water bodies. However, such matrix contains impurities and compounds that are not of interest, thus it is necessary some sample preparation for cleaning and preconcentration of the target analyte. In this context, the objective of this work was to develop a molecularly imprinted polymer for solid phase extraction as sample preparation for the determination of fluoxetine in effluents by liquid chromatography coupled to a diode arrangement detector, HPLC-DAD. Molecularly imprinted polymers were synthesized with acrylic acid, methacrylic acid and styrene as functional monomers. The yields of synthesis were 67.2% for styrene, 64.0% for acrylic acid and 62.2% for methacrylic acid. The selectivity between caffeine and fluoxetine was evaluated, resulting in better affinity of the polymer with the antidepressant. The adsorption occurs as a pseudo second order reaction, with better adsorption of the imprinted polymer than the non-imprinted polymer. By applying the solid phase extraction in effluent and analyzing it by the developed and validated HPLC-DAD method, the recovery value for the molecularly imprinted polymer (30.6%), although below the desired one, was shown to be much higher than the recovey value for commercial C18 cartridge (2.1%).

Orientadores: Adriana Vitorino Rossi, Regina Buffon / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-22T19:48:13Z (GMT). No. of bitstreams: 1 Manzoor_Suryyia_D.pdf: 4523839 bytes, checksum: 9aa2a7bc8376699193b0d5e83f0ec0f5 (MD5) Previous issue date: 2013 / Resumo: Este trabalho envolveu um estudo elaborado da técnica de impressão molecular para síntese, caracterização e avaliação de materiais impressos molecularmente (MIMs) para fluconazol (FLU), cafeína (CAF) e antocianinas (ACYs). O polímero de impressão molecular para FLU (FLUMIP) foi sintetizado utilizando-se ácido metacrílico (monômero funcional), etilenoglicoldimetacrilato (EGDMA) (agente reticulador) e acetonitrila em polimerização térmica. O FLUMIP foi caracterizado e aplicado como sorvente em cartuchos de extração em fase sólida (SPE). Sua capacidade de interação seletiva com o analito foi avaliada, obtendo-se alta afinidade para FLU, em comparação com análogos estruturais, com limite de detecção menor que 1,63X10 mmol/L com cromatografia de ultra alta eficiência acoplada com espectrometria de massas. Este MIP foi usado em cartuchos de SPE para extrair o analito de medicamento em cápsula, com recuperação de 91±10 % (n=9). Outro MIM obtido foi uma sílica organicamente modificada (ORMOSIL) para extração de CAF, a partir da reação de metacrilato de 3- (trimetoxisilil) propila e acetato de vinila, seguindo-se condensação e hidrólise com tetraetilortosilicato usando CAF como molécula modelo. Este ORMOLSIL foi caracterizado e testado quanto à sua eficácia de extrair CAF de amostras de café, com recuperação de 88±5 % (n=9); ele atuou como grupo seletivo com alta porcentagem de recuperação para teofilina (77 %) e teobromina (82 %). Limites de detecção e quantificação 5,14x10 e 1,71x10 mmol/L respectivamente foram obtidos com cromatografia líquida de alta eficiência. Também foi sintetizado um MIP usando rutina molécula modelo (RUTMIP), acrilamida (monômero funcional), EGDMA (agente reticulador) e tetraidrofurano por polimerização em bulk. Embora tenha sido alcançada impressão bem sucedida de rutina, confirmada pela comparação de afinidade de RUTMIP em aplicação de SPE (12 vezes maior que afinidade do polímero não impresso), não se alcançou a seletividade esperada para ACYs utilizando o RUTMIP / Abstract: This work involves an elaborative study of molecularly imprinting technique. Keeping in view its robustness and selectivity, this technique was applied for the synthesis of molecularly imprinted materials for the extraction of fluconazole (FLU), caffeine (CAF) and anthocyanins (ACYs). Molecularly imprinted polymer (MIP) for FLU (FLUMIP) was synthesized using methacrylic acid (functional monomer), ethyleneglycoldimethacrylate (crosslinker) and acetonitrile through thermal polymerization. The FLUMIP was characterized and applied as sorbent in solid phase extraction (SPE) cartridges. It was then evaluated for its ability to selectively interact with the analyte and presented an apparent affinity for FLU, which was confirmed by comparing it with structural analogues. The application of ultra high performance liquid chromatography with spectrometer mass detection, allowed a limit of detection 1.63x10 mmol/L. Furthermore, the SPE procedure was applied to extract FLU from medicine samples with recovery of 91±10 % (n=9). An organically modified silica (ORMOSIL) for CAF was also synthesized by reacting vinyl acetate and 3- (trimethoxysilyl) propyl methacrylate, followed by the condensation and hydrolysis with tetraethyl orthosilicate, using CAF as template molecule. The ORMOSIL was characterized and tested for its efficiency to extract the analyte from coffee samples and the percentage recovery of 88±5 % (n=9) was obtained. The cross reactivity studies for theophylline and theobromine showed high recovery (77 % and 82% respectively). The limit of detection and quantification, 5.14x10 and 1.71x10 mmol/L respectively, were achieved using high performance liquid chromatography. Also, a MIP for ACYs (RUTMIP) was synthesized using rutin (template molecule), EGDMA (cross linker) and tetrahydrofuran by the bulk polymerization method. A successful imprinting of rutin was attained. This can be confirmed by the high affinity of rutin for MIP (12 times greater than non imprinted polymer) during SPE procedure; however, the RUTMIP was not efficient enough to selectively extract ACYs from vegetal extracts / Doutorado / Doutora em Ciências

Orientador: Marcos Nogueira Eberlin / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-22T00:48:57Z (GMT). No. of bitstreams: 1 Fernandes_RaquelMariaTrindade_D.pdf: 2391491 bytes, checksum: e0ced742cb6fd1e2732195078347fd99 (MD5) Previous issue date: 2012 / Resumo: O presente trabalho descreve a utilização de polímeros de impressão molecular (MIP) no preparo de amostra para a extração seletiva de fármacos em matrizes biológicas com determinação por LC-MS/MS e MS/MS. Inicialmente foi sintetizado e caracterizado um MIP seletivo a omeprazol, sendo o mesmo empregado na extração com fase sólida molecularmente impressa (MISPE) de omeprazol em amostras de plasma humano, seguido de determinação por LC-MS/MS. A metodologia foi validada por meio do estudo dos parâmetros: precisão (repetibilidade e precisão intermediária), exatidão (recuperação), curva analítica, intervalo de linearidade, limite de detecção ¿ LD e limite de quantificação ¿ LQ, e seletividade. O limite de quantificação obtido foi de 5 ng mL. Posteriormente, foi sintetizado e caracterizado um MIP seletivo a cocaína, sendo este empregado na extração em fase sólida molecularmente impressa (MISPE) online de cocaína em amostras de urina de usuários de drogas, seguido da quantificação por MS/MS. O limite de quantificação obtido foi de 10 ng mL. A seletividade do método foi avaliada pelo estudo de adsorção de metabólitos (benzoilecgonina e cocaetileno) e interferente (lidocaína) pelo polímero sintetizado e posterior determinação por MS/MS. / Abstract: The present work describes the applications of molecularly imprinted polymers (MIP) in sample preparation for the selective extraction of drugs in biological matrices by LC-MS/MS and MS/MS. Initially a MIP selective for omeprazolewas synthesized and characterized. It was used in molecularly imprinted solid phase extraction (MISPE) of omeprazole from human plasma samples, followed by LC-MS/MS determination. The methodology was validated by studying the parameters: precision (repeatability and intermediate precision), accuracy (recovery), calibration curve, linear range, detection limit - LOD and quantification limit - LOQ, and selectivity. The quantification limit was 5 ng ml. Subsequentlya MIP selective for cocaine was synthesized and characterizedwhich was used in online molecularly imprinted solid phase extraction (MISPE) for cocaine in urine samples of drug users, followed by quantification by MS / MS. The quantification limit was 10 ng mL. The selectivity of the method was evaluated by studying the adsorption of metabolites (benzoylecgonine and cocaethylene) and an interferent (lidocaine) by the synthesized polymer with subsequent determination by MS / MS. / Doutorado / Quimica Analitica / Doutora em Ciências

The diploma thesis is focused on the preparation and optimization of molecularly imprinted polymers (MIP) selective for chymotrypsinogen A as well as on the use of these MIP as recognition entities in the sensor. MIP was prepared by suspension polymerization using a mixture of functional methacrylate-based monomers. Prepared MIP was optimized (e.g. binding properties, selectivity and isolation of chymotrypsinogen from a complex matrix of human breath) by capillary electrophoresis with fluorescence detection ( = 532 nm). Finally, the combination of MIP with quartz microbalances was demonstrated as a promising sensor for the detection of proteins from human breath condensate.

Les polymères à empreintes moléculaires (MIP) sont des matériaux synthétiques capables de mimer les anticorps biologiques. En effet, ils possèdent deux des principales caractéristiques de ces derniers, à savoir : la capacité de reconnaître et de se lier spécifiquement à des molécules cibles. De plus, leur synthèse facile, leur bas coût de production, leur haute spécificité et stabilité par rapport aux anticorps naturels font des MIP une alternative intéressante. En effet, les propriétés de reconnaissance moléculaire des MIP permettent d'envisager leur utilisation dans une vaste gamme d’applications. Ils sont ainsi largement exploités dans les sciences séparatives pour l'analyse d'échantillons environnementaux ou agro-alimentaires, ou comme élément de reconnaissance dans des biocapteurs. Récemment, des applications de ces matériaux dans les domaines biologiques et biomédicaux ont émergé comme pour la détection, l'extraction et l"élimination de molécules indésirables dans l'organisme, la vectorisation ou l'administration contrôlée des médicaments. Dans nos recherches, nous avons développé des MIP dégradables par voie biochimique ou enzymatique, ayant une application potentielle en tant que système de libération contrôlé de molécules. En général, les MIPs sont synthétisés par polymérisation radicalaire libre en utilisant une formulation composée de monomères fonctionnels, d'agents de réticulation, et d'une molécule cible servant à réaliser l'empreinte moléculaire. Dans ce travail de thèse, nous avons utilisé pour la synthèse de MIP dégradable des agents de réticulation clivables contenant, soit une fonction chimique dégradable par voie chimique ou enzymatique (ponts disulfures et phosphatediester), soit un disaccharide issus d'agro-ressources et pouvant être naturellement hydrolysé par des enzymes. En présence d'un réactif spécifique (agent réducteur ou enzyme), les liaisons dites "sensibles" aux réactifs chimiques ou enzymatiques peuvent être clivées, ce qui entraîne une dégradation de la matrice polymérique. Le polymère perdra alors sa capacité de reconnaissance et de liaison à la molécule cible et permettra la libération de celle-ci. Nous pensons donc, que les nouveaux MIP dégradables pourraient avoir un énorme potentiel comme vecteurs "intelligents" dans des applications médicales tels que les systèmes de libération contrôlée de médicament. Finalement, nous avons étudié la dégradation par des microorganismes de la structure de base de ce type de polymères, en utilisant comme modèles des chaines linéaires et réticulées. / Molecularly imprinted polymers (MIPs) are biomimetic synthetic receptors that possess two of the most important features of biological antibodies – the ability to recognize and bind specific target molecules. Owing to their easier preparation, lower cost, higher specifity and stability compared to antibodies, they have the potential to be widely applied for environemental and food analysis. Recently, MIPs also emerged in the biochemical field as diagnostic tools, chemicals traps to remove undesirable substance from the body, or drug delivery systems, where usually the combination of biocompatibility and degradability after its use is desirable. Here, we developed biochemically or enzymatically degradable MIPs, which have potential applications as activation-modulated drug delivery systems. In general, MIPs are prepared by radical polymerization of functional monomers and cross-linkers in the presence of a target molecule acting as template. Degradable MIPs were synthesized using cleavable cross-linkers containing a degradable group (disulfide bond or phosphate ester bond) or derived from a natural disaccharide. In the presence of a cleaving reagent (reducing agent or enzyme), the chemo or enzyme-sensitive bond could be cleaved, resulting in the degradation of the polymer matrix. The degraded polymers looses the binding sites structure resulting in the loss of recognition and binding capacity towards the target molecules, and thus in the release of bound molecules. These degradable MIPs provide new opportunities as “smart” vectors for controlled delivery of active molecules in biomedical applications. Finally, the biodegradation of the polymer backbone by bacteria was investigated.

Cette thèse décrit le développement de capteurs à fibre optique hautement sélectifs, utilisant des polymères à empreintes moléculaires (MIPs, de l’anglais molecularly imprinted polymers) comme éléments de reconnaissance, et se basant sur la fluorescence pour la détection. Nous avons étendu l’étude à d’autres types de capteurs et de méthodes de détection optiques, toujours basés sur les MIPs. Les MIPs sont des récepteurs synthétiques biomimétiques possédant des cavités spécifiques pour une molécule cible. Produits par un processus de moulage à l’échelle moléculaire, les MIPs sont capables de reconnaître et de se lier à leurs molécules cibles, avec des spécificités et affinités comparables aux récepteurs naturels. De plus, comparé aux récepteurs biologiques, les MIPs sont plus stables, moins chers et plus faciles à intégrer dans les procédés standard industriels de fabrication. Ainsi, les MIPs apparaissent comme une alternative intéressante aux biomolécules entant qu’éléments de reconnaissance dans les biocapteurs. Dans la première partie de la thèse (Chapitre 2), les MIPs ont été synthétisés en tant que micropointe à l’extrémité d’une fibre optique, par polymérisation in-situ induite par un laser en seulement quelques secondes. Les paramètres photoniques et physico-chimiques ont été optimisés pour moduler les propriétés des micro-objets de polymères. Des nanoparticules d’or ont été incorporées dans la micropointe de MIP afin d’induire une exaltation du signal. Afin de prouver l’efficacité de notre capteur, les études initiales ont été réalisées avec un MIP synthétisé avec le Ncarbobenzyloxy- L-phenylalanine (Z-L-Phe) comme template et le dérivé d’acide aminé fluorescentdansyl-L-phenylalanine, comme analyte. La fluorescence a été collectée de l’extérieur au niveau de la micropointe par une fibre optique connectée à un spectrofluorimètre, ou par collection du signal fluorescent ré-émis dans l’un des bras d’une fibre bifurquée en Y. L’analyse fluorescent a pu être détecté à des concentrations de l’ordre du nM. Afin de quantifier les analytes non fluorescents, un monomère fluorescent, possédant un groupe naphthalimide, a été incorporé dans le MIP ; celui-çidéployant une augmentation de la fluorescence quand l’analyte se lie. Utilisant ce système avec un MIP spécifique pour l’herbicide 2,4-D (acide 2,4-dichlorophénoxyacétique), des concentrations aussi basses que 2,5 nM en 2,4-D ont pu être mesurées. Le capteur MIP a également été appliqué à des analytes d’intérêt pour la sécurité alimentaire et le domaine nanostructurées. Cette étude pose les bases pour le développement futur de nanocapteurs et de Dans la dernière partie (Chapitre 4), une méthode d’analyse novatrice, basée sur l’utilisation des MIPs et l’analyse par polarisation de fluorescence, a été développée en vue de permettre la quantification directe et rapide d’analytes dans des échantillons alimentaires et environnementaux. Cette technique a été appliquée avec succès pour détecter des antibiotiques fluoroquinolones dans l’eau du robinet et le lait, en-dessous de leur limite maximale de résidus. En conclusion, nous pouvons dire que ce travail ouvre la voie vers l'application d'une nouvelle génération de capteurs optiques portables, robustes et miniaturisables basés sur les MIPs, pour des mesures «sur-site » et la quantification en temps réel d’analytes biologiques et environnementaux dans des milieux complexes. / This thesis describes the development of highly selective fiber optic sensors using molecularly imprinted polymers (MIPs) as recognition elements associated with fluorescence for detection. Additionally, we extended the study to the development of other MIP-based optical sensors and sensing methods. MIPs are synthetic biomimetic receptors possessing specific cavities designed for a target molecule. Produced by a templating process at the molecular level, MIPs are capable of recognizingand binding target molecules with selectivities and affinities comparable to those of natural receptors. Compared to biological recognition elements, MIPs are more stable, cheaper and easier to integrate into standard industrial fabrication processes. Hence, MIPs have become interesting alternatives to biomolecules as recognition elements for biosensing. In the first part of this thesis (Chapter 2), MIPs were synthesized by in-situ laser-induced photopolymerization in only a few seconds, as a micrometer-sized tip at the extremity of a telecommunication optical fiber. Photonic and physico-chemical parameters were optimized to tailor the properties of the polymer micro-objects. Gold nanoparticles were incorporated into the MIP microtip for signal enhancement. To prove the efficiency of the sensor, initial studies were performed with a MIP templated with N-carbobenzyloxy-L-phenylalanine (Z-L-Phe) and the fluorescent amino acid derivative dansyl-L-phenylalanine as analyte. The fluorescence was collected either externally at the tip level by an optical fiber connected to a spectrofluorimeter or by collection of the fluorescent signal re-emitted into the fiber through the second arm of a Y-shaped bifurcated fiber. The fluorescent analyte could be detected in the low nM concentrations. In order to monitor nonfluorescent analytes, a naphthalimide-based fluorescent monomer was incorporated into the MIP during its synthesis; fluorescence enhancement was observed when analyte binding occurs. Using this system, the sensor containing a MIP specific for the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), could detect and quantify this analyte at concentrations as low as 2.5 nM. The signaling MIP-based sensor was also applied to analytes of interest for food safety and biomedical applications, such as the mycotoxin citrinin and the sphingolipid, D-erythro-sphingosine-1-phosphate. In the second part of the thesis (Chapter 3), a different type of fiber optic sensor: cheap, fast and made for “single-use”, was developed by using 4-cm long disposable polystyrene evanescent wave optical fiber waveguides. The coating of the MIP was either performed ex-situ, by dip-coating the fiber in a suspension of MIP particles synthesized beforehand, or in-situ by evanescent-wave photopolymerization directly on the fiber. The resulting fiber optic sensor could detect 2,4-D in the low nM range and demonstrated specific and selective recognition of the herbicide over its structural analogues and other non-related carboxyl-containing analytes. Additionally, we demonstrated the versatility of the system by applying the evanescent wave fiber optic sensor to detect citrinin, a mycotoxin, by simply coating the waveguide with a MIP specific for citrinin. This type of technology could possibly be extended to detect other carboxyl-containing analytes, as long as a specific MIP for the concerned analyte is available. In parallel, the technique of evanescent-wave photopolymerization was used for the synthesis of signaling MIP microdots on continuous and nanostructured gold films. This study lays the foundations for future development of plasmonic MIP nanosensors and microchips. In the last part of the thesis (Chapter 4), an innovative sensing method, based on the use of MIPs and analysis by fluorescence polarization, was developed in order to allow the fast and directquantification of analytes in food and environmental samples.