Part I: Successful transition of polymer coated, ATR-FTIR sensor devices from a laboratory environment to real world field applications for detecting and quantifying VOCs in water is shown. Simultaneous, quantitative detection of BTX mixtures in water during enrichment into polymer coated ZnSe ATR elements has been performed. The obtained results showed accurate detection and quantification to the low ppb concentration region. Fiber-optic evanescent field measurement campaigns have been conducted at simulated field conditions during which concentration gradients of various VOCs in the mg/L range have been monitored successfully. The first test of an ATR based, polymer coated sensor system under real world field conditions, the chlorobenzene concentration in groundwater at mg/L levels was determined. An interesting aspect of these measurements was the experimental proof for the dependence of analyte extraction dynamics on the flow conditions of the sample matrix surrounding the extractive polymer membrane. The obtained results demonstrate that MIR evanescent field sensors are suitable for in-situ analysis at real world field conditions for environmental monitoring applications. PART II: Recently, measurements of disturbed soils have shown different spectral contrast in comparison to undisturbed soils. In this work first measurements at controlled laboratory conditions have been performed to investigate individual minerals of the soil matrix and their spectral characteristics under various environmental conditions. ATR spectroscopy has been applied to investigate multi-disperse quartz sand and mono-disperse soda lime glass spheres samples. For the investigation of spectral differences between pristine and disturbed quartz sand, a wetting/drying procedure with subsequent sample aerating has been developed. In addition to established differences in spectral contrast of disturbed and undisturbed soil, a strong spectral shift of absorption features was observed. When probed with s- or p-polarized light, both samples showed strong LO-TO mode splitting. The studies also reveal that the main reason for spectral differences of pristine and disturbed soils is caused by water facilitated changes of the particle size distribution in the probed volume. The presented results advance the variety of spectral characteristics useful for the detection of disturbed soils (i.e. possible landmine sites) with MIR imaging systems.

Substantial amounts of methane are sequestered in naturally occurring ice-like formations known as gas hydrates. In particular, oceanic gas hydrates are globally distributed in complex heterogeneous ecosystems that typically occur at depths exceeding 300 m. Gas hydrates have received attention for their potential as an alternative energy resource, as marine geohazards, and their role in cycling of greenhouse gases. In addition, chemosynthetic communities often play a vital role in the cycling and sequestration of carbon emanating from cold hydrocarbon seeps surrounding hydrate sites. Research efforts are presently striving to better understand the significance and complexity of these ecosystems through the establishment of seafloor observatories capable of long-term monitoring with integrated sensor networks. In this thesis, infrared (IR) spectroscopy has been implemented for the investigation of molecular-specific signatures to monitor gas hydrate growth dynamics and evaluate carbonate minerals, which are intimately connected with complex chemosynthetic processes occurring in these harsh environments. The first fundamental principles and data evaluation strategies for monitoring and quantifying gas hydrate growth dynamics utilizing mid-infrared (MIR) fiber-optic evanescent field spectroscopy have been established by exploiting the state-responsive IR absorption behavior of water. This has been achieved by peak area evaluation of the O-H stretch, H-O-H bend, and libration modes and assessing peak shifts in the 3rd libration overtone and libration bands during the formation and dissociation of simple clathrate hydrates of methane, ethane, and propane formed from aqueous solution. Hydrate growth and monitoring was facilitated with a customized pressure cell enabling operation up to ~5.9 MPa with spectroscopic, temperature, pressure, and video monitoring capabilities. Furthermore, the initial feasibility for extending the developed IR spectroscopic hydrate monitoring strategies into oceanic gas hydrate ecosystems has been demonstrated through the evaluation of potential spectroscopic interferences from sediment matrices in samples collected from two hydrate sites in the Gulf of Mexico (GoM). With exception of the libration band, the primary IR absorption features of water are readily accessed within hydrated sediment samples. Additional consideration for potential long-term hydrate monitoring applications revealed that the collection of approx. 2 IR spectra per day should enable direct insight into the temporal dynamics of hydrates...

L’électronique organique reste un domaine de recherche prolifique grâce à la diversité de structures moléculaires accessible par la synthèse organique. Les matériaux moléculaires offrent des possibilités de mises en forme inédites comme les techniques de dépôt en solution, utilisables dans la conception de dispositifs organiques sur supports plastiques. Nos travaux de recherche mêlent électrochimie, conception et caractérisations électriques de dispositifs et mesures capteur. Ils abordent deux thématiques : l’élaboration de nouveaux transducteurs à base de polyanilines substituées et de phtalocyanines et l’étude de l’influence de la modification électrochimique de surface sur le comportement de dispositifs connus.Nous avons tout d’abord élaboré des hétérojonctions latérales polymère – phtalocyanine en utilisant les propriétés des polyanilines. De par leur géométrie, ces nouveaux dispositifs diffèrent de l’hétérojonction MSDI (Molecular Semiconductor – Doped Insulator), transducteur conductimétrique bicouche développé au laboratoire pour la détection de gaz comme l’ozone ou l’ammoniac. La caractérisation complète de la poly(2,3,5,6-tétrafluoroaniline) indique que ce polymère est peu conducteur, en comparaison de la polyaniline dont la conductivité peut être augmentée par dopage acido-basique. La présence des fluors empêche l’émergence du régime conducteur que l’on retrouve en milieu acide pour la polyaniline et la poly(2,5-diméthoxyaniline). Ces trois polymères, électrodéposés sur électrodes d’ITO interdigitées ont permis, après sublimation de la bisphtalocyanine de lutécium, de construire les hétérojonctions latérales. Le comportement électrique des différents dispositifs, étudié notamment par spectroscopie d’impédance, diffère en fonction de la nature des substituants de la polyaniline électrodéposée. Enfin, des mesures capteur ont montré la possibilité de détecter l’ammoniac en milieu humide, avec une limite de détection sub ppm.De précédents travaux sur l’élaboration de MSDI ont souligné le rôle primordial des interfaces, notamment dans le cas des n-MSDI qui présentent une hétérojonction p-n. Outre le changement de la nature chimique de la sous-couche employée, une autre manière de jouer sur les interfaces est de modifier électrochimiquement la surface des électrodes interdigitées, par réduction de sels de diazonium. Nous avons ainsi greffé différents benzènes substitués, dont certains ont conduit à la formation de multicouches comme l’ont révélée des mesures de microbalance à quartz électrochimique. Les différentes modifications de surface ont surtout joué le rôle de barrière isolante, amplifiant le comportement non linéaire des caractéristiques courant-tension des MSDI. Le greffage du 2,5-diméthoxybenzène a permis d’améliorer significativement la sensibilité à l’ammoniac de la MSDI à base d’hexadécafluorophtalocyanine de cuivre et de bisphtalocyanine de lutétium, avec une limite de détection de l’ordre de 200 ppb. / Organic electronics remains a fruitful research field thanks to the diversity of molecular structures reachable by organic synthesis. Molecular materials offer convenient shaping processes, such as solution processing techniques, which can be used for the fabrication of organic devices on plastic substrates.Our works can be summarized as the elaboration of conductometric devices thanks to electrochemistry and the study of their electrical and sensing properties. They deal with two topics: the development of new transducers based on substituted polyanilines and phthalocyanines and the study of the influence of electrochemical modifications on the behavior of known devices.We first developped polymer - phthalocyanine lateral heterojunctions using the properties of polyanilines. Because of their geometry, these new devices differed from the MSDI heterojunction (Molecular Semiconductor - Doped Insulator), a bilayer-based conductometric transducer developed in the laboratory for the detection of gases such as ozone or ammonia. The comprehensive study of poly (2,3,5,6-tetrafluoroaniline) indicated that this material was a poor conducting polymer, compared to polyaniline whose conductivity can be increased by acid-base doping. The presence of fluorine atoms prevented the emergence of the conductive regime found in acidic medium for polyaniline and poly (2,5-dimethoxyaniline). These three polymers, electrodeposited on interdigitated ITO electrodes, allowed us, after sublimation of the lutetium bisphthalocyanine, to build lateral heterojunctions. The electrical behavior of the different devices, studied in particular by impedance spectroscopy, differed according to the nature of the substituents of the electrodeposited polyaniline. Finally, sensing measurements revealed their efficiency to detect ammonia in humid atmosphere, with a sub-ppm limit of detection.Previous works on the development of MSDI emphasized the primary role of interfaces, particularly in the case of n-MSDI that contained a p-n heterojunction. In addition to the modification of the chemical nature of the underlayer, another way to play with the interfaces is to electrochemically modify the surface of the interdigitated electrodes by reducing diazonium salts. Thus, we grafted various substituted benzenes, some of which led to the formation of multilayers as revealed by electrochemical quartz microbalance measurements. The various surface modifications mainly acted as an insulating barrier that amplified the nonlinear behavior of the current-voltage characteristics of MSDI. The grafting of 2,5-dimethoxybenzene significantly improved the ammonia sensitivity of MSDI based on copper hexadecafluorophthalocyanine and lutetium bisphthalocyanine, with a limit of detection of around 200 ppb.

The present work describes the development of a highly sensitive and selective molecularly imprinted electrochemical sensor for 4-nitrophenol detection. A glassy carbon electrode was modified with vyniltrimethoxisylane (VTMS) and multiwall carbon nanotubes (MWCNT). The introduced nanocomposite increased surface area and active sites for electron transfer. When the sillane is used on the synthesis, it is named MIS (molecularly imprinted silane) and NIS (non-imprinted silane) when the analyte is not on the synthesis. For those silane films characterization, it was used the scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and fourier transform infrared spectroscopy (FTIR). This sensor showed its best performance in 0.1 mol L-1 phosphate buffer solution, at pH 7.0. After optimizing the operational conditions, this sensor provided a linear response range for 4-NP from 0.1 up to 100 μmol L-1 and good parameters as LOD, LOQ and sensibility, 0.03 μmol L-1, 0.1 μmol L-1 and 1.4×10-2 A mol L-1 respectively. Furthermore, the MIS/PNP sensor exhibited good stability with adequate reproducibility and accuracy. / No presente trabalho é descrito o desenvolvimento de um sensor eletroquímico altamente sensível e seletivo baseado na tecnolgia dos Polímeros Impresso Molecularmente para detecção de 4-nitrofenol. Um eletrodo de carbono vítreo foi modificado com viniltrimetoxisilano (VTMS) e nanotubos de carbono de pardes múltiplas (MWCNT). O nanocompósito de carbono introduzido aumentou a área superficial e os locais ativos para transferência de elétrons. No método sol-gel quando um sillano é usado na síntese, é denominado MIS (Molecular Imprinted Silane) e NIS (non-imprinted Silane) quando o analito não está na síntese. Para a caracterização dos filmes de silanos utilizou - se a microscopia eletrônica de varredura (MEV), a análise termogravimétrica (TGA) e a espectroscopia de infravermelho por transformação de Fourier (FTIR). Este sensor apresentou o seu melhor desempenho em solução tampão fosfato 0,1 mol L-1, a pH 7,0. Depois de otimizado as condições operacionais, este sensor proporcionou uma faixa de resposta linear para o 4-nitrofenol de 0,1 a 100 μmol L-1 e bons parâmetros como limite de detecção, quantificação e sensibilidade de 0,03 μmol L-1, 0,1 μmol L-1 e 1,4×10-2 A mol L-1 respectivamente. Além disso, o sensor MIS/4-nitrofenol apresentou boa estabilidade com reprodutibilidade e precisão adequadas.

Les champignons sont des biocontaminants courants des environnements intérieurs. De nombreuses études ont démontré leur rôle dans la dégradation des supports que ces microorganismes colonisent tels que les matériaux de construction, les ouvrages ou les œuvres d'art. De plus, ces biocontaminants sont susceptibles d'induire des allergies, des infections, des toxi-infections ou encore des irritations. Depuis 2005, une technique de détection de la croissance fongique, basée sur la recherche de traceurs chimiques spécifiques dans l'air, et un indice de contamination fongique (ICF), ont été développés et validés au cours de différentes campagnes de mesures dans l'habitat, les bureaux, les écoles, les crèches… L'objectivation d'une croissance fongique dans un environnement s'appuie sur des prélèvements par adsorption, une analyse chromatographique au laboratoire (GC/MS) et le calcul de l'ICF. Dans le cadre de la surveillance de la qualité microbiologique de l'air des environnements intérieurs, cette thèse a pour ambition de prolonger ces travaux en développant notamment un système de microcapteurs chimiques adapté à la mesure in situ. Cette recherche repose à la fois sur la méthode de détection fongique développée au CSTB et sur l'expertise scientifique et technique de l'ESIEE en matière de miniaturisation d'instruments de mesure, grâce à l'apport des microtechnologies. Le premier axe de cette étude a consisté à identifier expérimentalement les COV du métabolisme fongique spécifiques d'un développement sur des matériaux du patrimoine. Ces molécules ont permis de consolider l'ICF et de définir deux indices spécifiques à la problématique des sites patrimoniaux, validés dans des châteaux, musées, bibliothèques, grottes ornées… Le second axe porte, d'une part, sur la conception la réalisation et la caractérisation des briques élémentaires du microsystème d'analyse, à savoir un module de préconcentration (adsorption TENAX), un module de séparation (microGC) et un module de détection (capteurs polymères) et d'autre part sur les intégrations et pilotage de ces briques / Fungi are common microbial contaminants of indoor environments. Many studies have demonstrated their role in the partial or total degradation of materials they colonize such as building materials, or works of art. Moreover, those microbial contaminants are likely to lead to allergies, infections, poisoning or irritation. Since 2005, a new technique based on researching specific chemical tracers in the air, was developed and validated during different measurement campaigns. This approach is now applied to various indoor environments (houses, offices, schools, child care centers…) and allows the detection of recent and/or hidden contamination. The purpose of this work is to study and characterize a rapid and continuous air analysing microsystem for detection of fungal contamination in closed spaces. This study falls within the field of monitoring air microbiological quality in indoor environments. In addition to the time saved by the absence of any laboratory analysis, this system must provide a permanent monitoring of environments frequented by people, such as museums, schools, hospitals... This research is based both on the fungal detection method developed by CSTB and on scientific and technical expertise of ESIEE : specialised in design and manufacturing of miniaturized analysis systems obtained using microtechnology. The first step of this study was to define the compounds' nature to be detected for different cases of contamination along with the sampling strategy for the system. The second step focuses on the microstructures design and fabrication to be used in microanalytical system based on gas chromatography and the development of a miniaturised analysis system. So the first part of the study consisted in defining specific fungal contamination tracers for heritage conservation sites. This list allowed to reinforce a fungal contamination index for indoor environments and to define two specific indexes designed for heritage conservation sites. The validation of these different indexes allowed checking their compliance with those types of environments (castles, museums, libraries, decorated caves...) by detecting all cases of contamination, along with the control remediation of former contaminated environments. The second part of the study enabled the design and validation of three main modules constitutive of the microanalytical system based on gas chromatography. A miniaturised analysis system based on three modules has been developed

Optimum detergent dosage during a washing process depends on water quality, degree of pollution and quantity of laundry. Particularly, water quality is an important factor. Other parameters like carbonate- or non-carbonate hardness and calcium / magnesium (Ca / Mg) ratio in addition to total hardness of water have an impact on the amount of detergent. This work discusses the possibilities realizing a detergent sensor that measures important parameters for the washing process and assess the ideal necessary amount of detergent during the washing process. The approach is to combine impedance spectroscopy with cyclic voltammetry in order to determine both water quality and concentration of detergent in the suds which build up the basis for an optimum detergent dosage. The results of cyclic voltammetry show that it is possible to identify the Ca / Mg ratio and the carbonate hardness separately, which is necessary for the optimization of the washing process. Impedance measurements identify total hardness and detergent concentrations.

No description available.

Hydrogen peroxide (H2O2) is extensively used in a broad range of industrial and medical applications, such as aseptic processing of food and pharmaceuticals, disinfection, water treatment plants, and decontamination of industrial effluents. H2O2 is believed to be responsible for chemical degradation of polymer membranes in Polymer-Electrolyte-Membrane (PEM) fuel cells. Therefore, a versatile H2O2 sensor that functions in different environments with different conditions is of practical importance in various fields. This dissertation presents the fabrication of a fiber-optic H2O2 sensing probe (optrode) and its H2O2 sensing behavior in different conditions. An H2O2 optrode is fabricated using chemical deposition of Prussian blue (PB) onto the tip of a multimode optical fiber. Sensing tests are performed in aqueous solutions at a constant pH and different concentrations of H2O2. Sensing features of the optrode (i.e. repeatability, durability, and reproducibility) are assessed by performing multiple sensing tests with several optrodes. The results show the prepared optrode is able to detect concentrations of H2O2 in aqueous solutions at a constant pH of 4 and the optrode features a repeatable and durable response at this condition. The functionality of optrodes at different pH values is further investigated by performing additional sensing experiments. These experiments are carried out in aqueous solutions with different concentrations of H2O2 at different pH values (i.e. pH 2-7). The sensor detects the presence of H2O2 at a range of pH values. Sensing behavior of optrodes toward detection and measurement of H2O2 concentrations is studied at the pH value corresponding to an operating PEM fuel cell (i.e. pH 2). The optrode is able to detect concentrations of H2O2 at this condition with a repeatable and durable response. The stability of PB films, prepared through different conditions, is investigated to address the stability of optrodes at elevated temperatures. PB films are first deposited onto the glass slides through three different chemical processes, and then at different synthesis temperatures. The PB films are left in Phosphate-Buffer-Solutions (PBS) with pH 2 and at elevated temperatures for a day. Finally, PB films are characterized using Fourier transform infrared spectroscopy (FTIR) to analyze their stability following PBS processing at operating temperatures and pH value corresponding to an operating PEM fuel cell (i.e. 80 °C and pH 2). The results of these experiments illustrate the PB films prepared through the single-source precursor (SSP) technique and at synthesis temperatures above 60 °C remain stable after the PBS processing. The proposed optrode shows reliable sensing behavior toward detection and measurement of H2O2 concentrations in aqueous solutions at different conditions. The prepared optrode has the potential for being developed and used in different industrial and medical fields, as well as an operating PEM fuel cell, to detect and measure H2O2 concentrations. / Graduate / 0794 / 0548 / 0485 / hakbarik@uvic.ca

O presente trabalho trata do desenvolvimento de sensores eletroquímicos que possuam características descartáveis e ao uso destes dispositivos para a determinação de diferentes analitos em amostras biológicas, farmacêuticas e de interesse ambiental. O desenvolvimento e a aplicação dos sensores foram divididos em seis capítulos. O primeiro capítulo corresponde a fabricação de conjuntos de microeletrodos em suporte de CD-RW e placa fenolite utilizando impressão com tinta toner. Os conjuntos de microeletrodos foram fabricados por meio da deposição de duas máscaras de toner em um substrato de cobre ou ouro. Os eletrodos fabricados neste capítulo foram caracterizados e aplicados nos capítulos subsequentes. Os resultados da aplicação do conjunto de microeletrodos de cobre (DCRM) foram descritos no segundo capítulo. Os dispositivos foram aplicados para a determinação de peróxido de hidrogênio em amostras de antisséptico bucal e clareadores dentais. As determinações foram realizadas em solução de tampão fosfato (pH 7.0) por meio da técnica de amperometria (E = -0,2 V). Estes sensores foram também aplicados para determinação de ácido acetilsalítico (AAS) em amostras farmacêuticas em solução de hidróxido de sódio 0,1 mol L-1 por amperometria (E = 0,6 V). A determinação de nitrato em amostra de água de rio foi realizada por amperometria (E = -0,45V) em solução de sulfato de sódio 0,1 mol L-1 (pH = 2,0). Os resultados obtidos com o sensor demonstraram o sucesso das aplicações. As principais vantagens deste dispositivo dizem respeito à simplicidade de fabricação, baixo custo do equipamento e rapidez das análises. A caracterização eletroquímica do sensor e a determinação de ciclopirox olamina em solução de tampão BR 0,1 mol L-1 (pH = 5,0) utilizando o conjunto de microeletrodos de ouro (CD-RW) foi apresentada no terceiro capítulo. Os resultados obtidos mostraram que é possível realizar a determinação desta espécie de interesse em soluções oftalmológicas. O desenvolvimento, a caracterização e aplicação de um novo conjunto de microeletrodos de ouro fabricados a partir da redução eletroquímica da 5-bromo-1,10-fenantrolina em solução de dimetilformalmida (DMF) foi investidada no quarto capítulo. A superfície foi bloqueada com um filme isolante de 1,10-fenantrolina e o sensor foi caracterizado como um conjunto de microeletrodos de ouro. O sensor foi aplicado para a determinação de peróxido de hidrogênio, nas condições descritas anteriormente a fim de avaliar a aplicabilidade deste dispositivo. Os resultados obtidos foram promissores. A utilização de um eletrodo de microbanda impresso na configuração \"back-to-back\" foi descrita no quinto capítulo. A configuração faz uso da impressão de um novo eletrodo nas costas de um eletrodo impresso \"tradicional\", aumentando com isso a sensibilidade do sensor. O eletrodo impresso na configuração \"back-to-back\" foi utilizado para a determinação de íons Pb(II) em amostras de água potável por meio da técnica de voltametria de redissolução anódica por onda quadrada e os resultados obtidos foram concordantes com os encontrados utilizando espectrometria de emissão atômica por plasma acoplado. Os eletrodos de microbanda impressos na configuração \"back-to-back\" modificados com nanotubos de carbono para a determinação de capsaicina e dopamina e com ftalocianina de cobalto (II) para determinação de hidrazina foram investigados no sexto capítulo. Os resultados obtidos foram concordantes com aqueles descritos em outros trabalhos encontrados na literatura. / This work presents results on the fabrication of disposable electrochemical sensors and the use of such devices for the determination of different analytes in biological, pharmaceutical and environmental samples. The development and application of these sensors have been divided into six chapters. The first chapter describes the fabrication of a microelectrode ensemble (CD-RW) using ink toner. The sensor was fabricated by deposition of two toner pattern masks on copper and gold substrates. The electrodes fabricated according this procedure were characterized and applied in subsequent chapters. The second chapter describes the use of a disposable copper random microarrays (DCRM) for the amperometric determination of three analytes: hydrogen peroxide in real samples (oral antiseptic and dental whitening) at -0.2 V in phosphate buffer (pH 7.0) solution, acetylsalicylic acid (ASA) in pharmaceutical formulations at 0.6 V in 0.10 mol L-1 NaOH solution and nitrate in river samples at -0.45V in a 0.10 mol L-1 sodium sulfate solution (pH 2.0). The good results obtained with the DCRM demonstrated the successful application of this new sensor. The main advantages of the proposed manufacturing procedure are the simplicity, low cost of equipment and the high speed of production. The third chapter presents results on the use of a gold random microarray (GRM) for the determination of ciclopirox olamine in 0.10 mol L-1 Britton Robinson buffer solution (pH 5.0). Following the optimization of the experimental parameters, the proposed sensor presented excellent analytical properties for the amperometric detection of ciclopirox olamine at +0.85 V. The usefulness of the GRM sensor was confirmed by determining ciclopirox olamine in commercial products and the results obtained agreed well with those found by potentiometric titration and the labeled values. The fourth chapter describes the fabrication of a random assembly of microelectrodes (RAMs) by electrochemical reduction of 5-bromo-1,10- phenathroline in N,N-dimethylformamide (DMF), generating the 1,10-phenanthroline radical, which was covalently grafted on gold electrodes. After several potential cycles, the gold surface was partially blocked with an insulating film of 1,10-phenanthroline and the resulting modified electrode exhibited the characteristics of RAMs for the electrochemical reduction of the reversible probe 1,4-benzoquinone in DMF. This sensor was applied for hydrogen peroxide detection at -0.2 V in phosphate buffer (pH 7.0) solution. The fifth chapter reports on the use of screen-printed back-to-back microband electroanalytical sensors for quantification of lead(II) ions in drinking water samples in 0.01 mol L-1 HCl and the validation of the results by ICP-OES. The sixth chapter shows results on the use of back-to-back screen-printed microband electrodes modified with single-walled carbon nanotubes and cobalt phthalocyanine. The electroanalytical applications of this novel electrode configuration were exemplified towards the sensing of dopamine, capsaicin and hydrazine.

Le but de ce travail de thèse consiste à étudier les propriétés physico-chimiques des verres chalcogénures afin de pouvoir les utiliser comme membranes de capteurs chimiques destinés pour le dosage des ions Hg²⁺. Dans un premier temps, les propriétés macroscopiques des systèmes vitreux AgY-As₂S₃ (Y = Br, I), HgS-GeS₂, AgI-HgS-As₂S₃ et AgI-HgS-GeS₂, telles que les densités et les températures caractéristiques (Tg et Tc) ont été mesurées et analysées selon les compositions des verres. Puis, dans un second temps, les propriétés de transport ont été étudiés à l'aide de la spectroscopie d'impédance complexe d'une part, ou d'autre part, par des mesures de la résistivité. Ces dernières montrent que les verres de chalcogénures dopés à l'halogénure d'argent présentent deux différents régimes de transports au-dessus du seuil de percolation xc ≈ 30 ppm : (i) domaine de percolation critique, et (ii) domaine contrôlé par modificateur. Vient ensuite la troisième partie, elle consiste à déchiffrer les relations composition/structure/propriété grâce à plusieurs études structurales. Des mesures par spectroscopie Raman, par diffraction de neutrons et de rayons X haute énergie, par diffusion des neutrons sous petits angles (SANS), ainsi que des modélisations RMC/DFT et AMID ont été réalisées. Enfin, la dernière partie de ce travail était une étude préliminaire des caractéristiques des nouveaux capteurs chimiques. Il a été consacré à l'étude des relations entre la composition et la sensibilité des membranes ainsi qu'aux limites de détection qui les définissent. / The aim of the thesis is to study the physicochemical properties of the silver halide doped chalcogenide glasses for the possibility to use them as chemical sensors for quantitative analysis of Hg²⁺ ions. First, the macroscopic properties of AgY-As₂S₃ (Y = Br, I), HgS-GeS₂, AgI-HgS-As₂S₃ and AgI-HgS-GeS₂ glassy systems such as the densities and the characteristic temperatures (Tg and Tc) were measured and analyzed according to the glass compositions. Second, the transport properties were studied using complex impedance and dc conductivity. Measurements show that the silver halide doped chalcogenide glasses exhibit two drastically different ion transport regimes above the percolation threshold at xc ≈ 30 ppm : (i) critical percolation, and (ii) modifier-controlled regimes. Third, to unveil the composition/structure/property relationships, various structural studies were carried out. Raman spectroscopy, high-energy X-ray diffraction, neutron diffraction and small-angle neutron scattering experiments, together with RMC/DFT and AMID modelling were employed. Finally, the last part was a preliminary study of the characteristics of new chemical sensors. It was devoted to study the relationship between the membranes' composition and sensitivity but also detection limits.