<p> Cathodic electrodeposition method has been developed for the fabrication of manganese oxide films for application in electrochemical supercapacitors (ES). The manganese oxide films prepared from KMn04 and NaMn04 aqueous solution showed an increasing deposition yield with the deposition time. The deposition rate decreases with increasing the concentration of deposition precursor. The obtained films were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction analysis (XRD), thermogravimetric and differential thermal analysis (TGA/DTA). The SEM observations revealed uniform films of highly porous nanostructure on different substrates. The capacitive behavior of the deposits was investigated by cyclic voltammetry and chronopotentiometry method in 0.1M NaS04 aqueous solutions. As prepared deposits exhibited pseudocapacitive behavior in the potential window of 0-1.0 V versus SCE with excellent cyclability. A maximum specific capacitance (SC) of 353 Fig was obtained for the 45 μg/cm2 film deposited from KMn04 solution on stainless steel foil, at a scan rate of 2 m V /s in the 0.1 M Na2S04 solution. It was found that the SC decreased with increasing deposit thickness and scan rate. No significant effect was obtained on the films prepared from 20 mM KMn04 on stainless steel after heat treatment at various temperatures. The capacitance of as-prepared electrode did not change by changing the electrolyte from Na2S04 to K2S04 solutions. However, higher capacitance values were observed by using electrolyte with higher concentration. Different structures of manganese oxides were obtained when different deposition precursors were used. No significant difference in capacitive behavior was found between the films prepared from different deposition precursor. However it was concluded that conductivity of the film is key in determining the performance of the electrodes. The effect of substrates on the electrochemical behavior has also been investigated by using stainless steel and nickel foils. </p> / Thesis / Master of Applied Science (MASc)

The biosensing field has grown in importance and research efforts over the last few years for many reasons including point of care sensing devices and possible early detection of diseases in the body. Dopamine sensing is discussed in this paper and the development of a dopamine sensing platform would lead to early detection of diseases linked to its abundance or lack thereof in the brain such as Parkinson's disease. This work focuses on the electrochemical methods of biosensing, specifically dopamine sensing, and this method involves the use of electrodes as its sensing component. Multimaterial electrode-embedded fibers are used as the sensing electrode and the electrode material presented is platinum (Pt). Platinum is employed because of its biocompatibility property. The electrodes are placed in the fiber by the method of convergence fiber drawing and the fiber ends are stripped to expose the electrode for application. To make the proposed sensing platform more cost-effective, the platinum is electrodeposited onto the multimaterial fiber's embedded electrode. We discuss the use of a W/Pt modified electrode and a pure platinum wire in dopamine sensing and demonstrate that Pt is indeed a good candidate for dopamine sensing. The results show that the sensitivity of the W/Pt modified electrode to dopamine is higher than that of a pure Pt wire. This work has shown the promising application of electrodeposition in developing a cheaper flexible biosensing platform and opens up the possibility of the development of wearable flexible smart textile sensors because of the use of flexible multimaterial fibers. / Master of Science / The idea of sensing is important to our world and various scientific developments in this area have improved our way of life as humans. Biological sensing, which is what this thesis focuses on, detects the presence of various substances in the body, and developments in the area of biosensing have led to the creation of devices that can detect diseases or gather general information about a person's anatomical state. There has been increased interest in the detection of dopamine as more studies show that some diseases such as Parkinson's disease are related to the amounts of dopamine present in the brain. In this work, we present a potential platform for sensing dopamine in vitro using electrochemistry. Multimaterial fibers with embedded electrodes capable of measuring dopamine were fabricated using a thermal drawing technique. The electrode material in this fiber is the most important part of the sensing platform as it is what determines how sensitive the fiber is to an analyte. The two main topics discussed in this work are the modification of the electrode material using an electrodeposition technique and the sensing of dopamine with the modified electrode using the electrochemical methods of cyclic voltammetry and differential pulse voltammetry. The material involved in the electrodeposition process is Platinum (Pt) and the results show that platinum is a suitable material for dopamine sensing.

Face à une croissance effrénée de la demande en indium et aux enjeux à la fois socio-économiques et politiques potentiels qu'il représente, le recyclage de l'indium contenu dans les équipements en fin de vie reste la seule alternative pour remédier à des risques de pénuries. Au-delà des aspects économique et stratégique, le recyclage de l'indium peut permettre de préserver l'environnement en évitant l'exploitation à grande échelle des gisements de minerais contenant l'indium. Par ailleurs, la toxicité de l'indium justifie à elle seule le développement de procédés de traitement de déchets en contenant. Pourtant, la récupération de l'indium à partir de déchets électroniques est actuellement assez peu développée, mis à part au Japon, où plusieurs procédés existent à l'échelle industrielle. Ces procédés sont toutefois peu respectueux de l'environnement et fortement énergivores. Dans ce travail de doctorat, le recyclage de l'indium par extraction liquide/liquide dans un liquide ionique suivie de son électrodéposition in situ nous est apparu comme un procédé prometteur, permettant de s'affranchir de l'étape souvent difficile de dés-extraction du cation métallique. Parmi les liquides ioniques que nous avons synthétisés et caractérisés, en termes de structure et de propriétés physico-chimiques, le bis(trifluorométhylsulfonyl) amidure de 1-butyl-1-éthylpipéridinium (BEPipNTf2) s'est avéré le plus adapté du fait de sa bonne stabilité cathodique, de sa faible viscosité, de son caractère hydrophobe et peu hygroscopique. Nous avons montré qu'en synergie avec l'oxyde de trioctylphosphine (TOPO) comme extractant, il est possible d'extraire plus de 90% de l'indium contenu dans une phase aqueuse 10-2 M en HCl. Le système électrochimique In(III)/In(0) dans le BEPipNTf2 a alors été étudié en présence de chlorures, d'eau, d'oxygène et de TOPO, espèces présentes à l'issue de l'étape d'extraction liquide/liquide de l'In(III). Une étude détaillée de l'influence des ions chlorures a notamment été réalisée, mettant en évidence la formation de chlorocomplexes d'indium lors de l'application d'un potentiel cathodique de réduction de l'In(III), ce qui modifie considérablement les caractéristiques électrochimiques du système In(III)/In(0). Les résultats obtenus montrent qu'il est possible d'électrodéposer de l'In(III) sous sa forme métallique dans le domaine de stabilité électrochimique du liquide ionique, et ceci de façon non réversible en présence de TOPO, dont l'électroactivité dans le domaine de potentiel correspondant porte néanmoins à croire que la réduction pourrait entraîner la présence d'impuretés organiques dans le dépôt d'indium et limiter la quantité de métal déposée. / Faced with explosive growth in demand for indium and, faced with challenges to both socio-economic and political potential it represents, the recycling of indium content in the equipments of end of life remains the only alternative to address risk of shortages. Beyond the economic and strategic aspects, recycling of indium can help preserving the environment by preventing large-scale exploitation of mineral ores containing indium. In addition, the toxicity of indium alone justifies the development of methods for treating waste containing indium. However, the recovery of indium from electronic waste is currently fairly limited, except in Japan where there are several processes at an industrial scale. However, these processes are not environmentally friendly and are energy-intensive In this PhD work, recycling of indium by liquid / liquid extraction in an ionic liquid followed by its electrodeposition in situ appeared to us as a promising process, to overcome the often difficult step of de-extraction of the metal cation. Among the ionic liquids that we have synthesized and characterized in terms of structure and of physicochemical properties, 1-butyl-1-ethylpiperidinium bis(trifluoromethylsulfonyl) imide (BEPipNTf2) has been shown most suitable because of its cathodic stability, its low viscosity, its hydrophobic and weakly hygroscopic character. We have shown that in synergy with the trioctylphosphine oxide (TOPO) as extractant, it is possible to extract more than 90% of the indium contained in a 10-2 M HCl aqueous phase. The electrochemical system In(III)/In(0) in the BEPipNTf2 was then studied in the presence of chlorides, of water, of oxygen and of TOPO, which are the species present after the liquid/liquid extraction step of the In(IIII). A detailed study of the influence of chloride ions has been particularly carried out, highlighting the formation of chlorocomplexes of indium when applying a cathodic potential of reduction of In(III), which significantly changes the electrochemical characteristics of the system In(III)/In(0), The results obtained show that indium (III) can be electrodeposited in its metallic form in the range of electrochemical stability of the ionic liquid and that this is non-reversible in presence of TOPO, whose electroactivity in the corresponding potential range suggests that the reduction could result in the presence of organic impurities in the deposition of indium and could limit the amount of metal deposited.

Dans le domaine stratégique des biocapteurs sans marquage, la détection de l'élément biologique est directement liée à la variation d'un paramètre physique donné du composé sensible (transducteur). Dans le cas de la détection de l'hybridation de l'ADN par spectroscopie d'impédance électrochimique non faradique (sans label redox), la détection se base sur le changement de conductivité de l'élément sensible. Celui-ci est généralement un matériau semi-conducteur. La présence sur sa surface, de charges électriques amenées par des biomolécules chargées, comme les brins d'ADN, induit, par un phénomène connu d' »effet de champ électrique », la création d'une zone de charge d'espace subsurfacique. Celle-ci se caractérise par la courbure vers la surface des niveaux énergétiques. En conséquence de quoi, l'impédance de l'interface électrolyte/ADN/semi-conducteur varie. Antérieurement, nous avions démontré la faisabilité de l'utilisation de films d'oxydes semi conducteurs, tels CdIn204, SnO2 pur ou dopé, présentant des surfaces denses 2D en tant qu'éléments sensibles dans des capteurs à ADN basés sur la détection par spectroscopie d'impédance électrochimique non faradique. Les résultats avaient montré que, si CdIn204 présentait une sensibilité supérieure à celle de SnO2, cet oxyde était en revanche très fragilisé durant les étapes de fonctionnalisation, ce qui n'est pas le cas de SnO2 qui est un oxyde stable et robuste chimiquement. L'objectif du présent travail a été (i) d'améliorer les performances des capteurs à base de SnO2 en utilisant cette fois des films nanostructurés (1 ou 3D) afin de développer la surface spécifique, et (ii) d'étudier comment la topologie de surface influe sur le signal de détection de l'hybridation de l'ADN. Dans un premier temps, différentes nanostructures de SnO2 ont été élaborées par la technique d'électrodéposition que nous avons montée et mise au point de façon à obtenir des films reproductibles. La morphologie désirée des films –nanofils 1D ou matrice nanoporeuse 3D- a été obtenue en modifiant la procédure et les paramètres de dépôt. Leurs caractéristiques microstructurales, morphologiques, chimiques et électriques ont été déterminées par DRX, MEB, XPS et spectroscopie d'impédance. Puis, en vue du greffage covalent d'ADN, un procédé de fonctionnalisation multi-étape a été réalisé. Enfin, dans un troisième temps, la détection de l'hybridation d'ADN sans marquage, réalisée par spectroscopie d'impédance électrochimique sur les deux types de films nanostructurés, a été réalisée. En parallèle, afin de valider l'hybridation de l'ADN, la détection par microscopie à fluorescence, soit en mode épifluorescence, soit en mode confocal, a été menée. En comparaison des surfaces denses 2D de SnO2 (étude antérieure), les résultats ont montré une sensibilité supérieure, avec une limite de détection observée d'ADN de 2 nM, montrant l'importance d'avoir une surface développée. La structuration en nanofils est plus favorable que la matrice nanoporeuse en terme de sensibilité. Par ailleurs, en utilisant des ADN cibles, soit non complémentaires, soit possédant une ou deux mutations, nous avons pu montrer le caractère hautement sélectif de notre capteur dans le cas des deux types de nanostructures. Ce travail fortement expérimental a aussi permis de montrer l'importance de l'organisation structurale et morphologique du matériau sensible sur la réponse du signal à l'hybridation d'ADN. En effet, dans le cas des nanofils, comme dans celui des films denses avec surface 2D, le signal de réponse donne systématiquement une augmentation d'impédance. Cela s'explique par le phénomène d'effet de champ explicité plus haut. En revanche, dans le cas de la matrice naporeuse de SnO2, l'hybridation d'ADN entraine une diminution de l'impédance ... / For environmental in situ diagnostic, as well as for medical point of care diagnostic, quick andaffordable sensing devices are of importance. Label-free biosensors based on electrical orelectrochemical detection methods can provide such features. In previous studies, we havedemonstrated for the first time the feasibility of using semiconductive SnO2 2D dense films fornon-faradic electrochemical impedance DNA detection. The aim of the present study is (i) toimprove the sensing performances by using SnO2 nanostructures in order to benefit from highspecific surface, and (ii) to study the influence of the morphology and microstructure on theimpedimetric DNA detection signal.We performed the cathodic electrodeposition of SnO2 nanostructures. By changing relevantprocessing parameters, two kinds of nanostructures were deposited: 3D nanoporous films and 1Dnanowires. Both nanostructures have been characterized in terms of morphology, microstructureand electrochemical properties.Our results emphasize the importance of both the microstructural and morphological organizationson the impedimetric signal upon DNA hybridization. Opposite tendencies are found. DNAhybridization induces a decrease of the impedance in the case of 3D-nanoporous films, whereasan increase of impedance is obtained in the case of 1D NWs. Indeed, following the dimensionalityof the nanostructures, either external cause - ion transport - or internal cause - field effectphenomenon - can contribute to the impedance variation.The performances of the sensors have also been analyzed, namely: sensitivity, selectivity andreusability. Compared to the 2D dense and 3D nanoporous films, the 1D SnO2 nanowires are morefavorable in term of sensitivity, showing a detection limit of 2 nM.

No description available.

No description available.

Naudojant chronopotenciometrijos metodą buvo tirta sidabro elektronusodinimo iš sulfitinių tirpalų kinetika. Eksperimentiniai tyrimai patvirtino negausius žinomus literatūrinius duomenis, kad sidabro elektrokristalizacija iš sulfitinių elektrolitų yra apsprendžiama lėta sidabro ad-atomų kristalizacija galvaninės dangos paviršiuje. Tai ypač akivaizdu pusiausvyrinio potencialo srityje. Nustatyta, kad patikimiausi rezultatai, tiriant krūvio pernešimo stadiją, gaunami maksimaliai nutolus nuo pusiausvyros potencialo. Tai lengviausia realizuoti chronopotenciometrijos sąlygomis, o nustatytas mainų srovės tankis svyruoja tarp 0,9 (kai tirpalo sudėtis 0,003 ir 0,115 ) iki 2,46 (kai tirpalo sudėtis 0,1 ir 0,77 ). Patikimiausi rezultatai buvo gauti matuojant mainų srovės tankių priklausomybes nuo laisvų sulfito jonų koncentracijos izopotencialių ( 0,300 ) tirpalų serijoje. Visuose izopotencialiuose tirpaluose buvo nustatyti krūvio pernašos viršįtampiai -60 – -160 intervale. Naudojantis lygtimi ir mainų srovės tankio priklausomybės nuo laisvų sulfito jonų koncentracijos grafiku iš eksperimentinių duomenų nuolinkio kampo apskaičiuotas reakcijos laipsnis 0,67. Atsižvelgiant į galimas paklaidas, tikėtina, kad jis yra lygus 1. Gauti rezultatai rodo, kad artimas vienetui reakcijos laipsnis sulfito jonų atžvilgiu atitinka teiginį, jog betarpiškai fazių sąlyčio riboje redukuojasi kompleksinė dalelė . Atsiradusios paklaidos greičiausiai yra susiję su tirpalo komponentų... [toliau žr. visą tekstą] / Silver electrodeposition from sulfite electrolytes is considered to be one of the most promising processes to replace the extremely toxic traditional cyanide-based silver plating solutions with the additional advantage, that sulfite electrolytes can be successfully applied for silver deposition for micro-electro-mechanical systems (MEMSs). Mechanism of metal complexes electroreduction is an important result, especially when it may have a wide range of applications in the future. However, electrodeposition also has several shortcomings, including sulfite ion oxidation by oxygen in air and relatively negligible cathodic current densities, which are too low for qualitative galvanotechnique. There are very few works dedicated to the chemistry and electrochemistry of silver sulfite complexes. Most publications related with this subject are concerned with the questions of applicability. The main objective of this study was the investigation of the silver sulfite complexes electroreduction kinetics. To achieve this goal, we studied the dependence of the exchange current density on the free sulfite ions concentration in a series of isopotential solutions. Our studies also allowed to determine the mechanism of this electrochemical charge transfer reaction.

Silver electrodeposition from sulfite electrolytes is considered to be one of the most promising processes to replace the extremely toxic traditional cyanide-based silver plating solutions with the additional advantage, that sulfite electrolytes can be successfully applied for silver deposition for micro-electro-mechanical systems (MEMSs). Mechanism of metal complexes electroreduction is an important result, especially when it may have a wide range of applications in the future. However, electrodeposition also has several shortcomings, including sulfite ion oxidation by oxygen in air and relatively negligible cathodic current densities, which are too low for qualitative galvanotechnique. There are very few works dedicated to the chemistry and electrochemistry of silver sulfite complexes. Most publications related with this subject are concerned with the questions of applicability. The main objective of this study was the investigation of the silver sulfite complexes electroreduction kinetics. To achieve this goal, we studied the dependence of the exchange current density on the free sulfite ions concentration in a series of isopotential solutions. Our studies also allowed to determine the mechanism of this electrochemical charge transfer reaction. / Naudojant chronopotenciometrijos metodą buvo tirta sidabro elektronusodinimo iš sulfitinių tirpalų kinetika. Eksperimentiniai tyrimai patvirtino negausius žinomus literatūrinius duomenis, kad sidabro elektrokristalizacija iš sulfitinių elektrolitų yra apsprendžiama lėta sidabro ad-atomų kristalizacija galvaninės dangos paviršiuje. Tai ypač akivaizdu pusiausvyrinio potencialo srityje. Nustatyta, kad patikimiausi rezultatai, tiriant krūvio pernešimo stadiją, gaunami maksimaliai nutolus nuo pusiausvyros potencialo. Tai lengviausia realizuoti chronopotenciometrijos sąlygomis, o nustatytas mainų srovės tankis svyruoja tarp 0,9 (kai tirpalo sudėtis 0,003 ir 0,115 ) iki 2,46 (kai tirpalo sudėtis 0,1 ir 0,77 ). Patikimiausi rezultatai buvo gauti matuojant mainų srovės tankių priklausomybes nuo laisvų sulfito jonų koncentracijos izopotencialių ( 0,300 ) tirpalų serijoje. Visuose izopotencialiuose tirpaluose buvo nustatyti krūvio pernašos viršįtampiai -60 – -160 intervale. Naudojantis lygtimi ir mainų srovės tankio priklausomybės nuo laisvų sulfito jonų koncentracijos grafiku iš eksperimentinių duomenų nuolinkio kampo apskaičiuotas reakcijos laipsnis 0,67. Atsižvelgiant į galimas paklaidas, tikėtina, kad jis yra lygus 1. Gauti rezultatai rodo, kad artimas vienetui reakcijos laipsnis sulfito jonų atžvilgiu atitinka teiginį, jog betarpiškai fazių sąlyčio riboje redukuojasi kompleksinė dalelė . Atsiradusios paklaidos greičiausiai yra susiję su tirpalo komponentų... [toliau žr. visą tekstą]

Complexos de coordenação de Cu(II), Ni(II), Zn(II) e Nb(V) foram obtidos com os íons acetato, citrato e oxalato como ligantes (complexos ex-situ) para serem aplicados em banhos de eletrodeposição. O objetivo é usar estes complexos como fontes de metais sem adição de aditivos os quais são os ligantes que estão coordenados. Como estudos de referência, foram investigados banhos de eletrodeposição contendo sais de sulfatos dos íons metálicos na presença de ligantes nas razões metal:ligante de 10:1 e 1:5; assim, complexos de coordenações similares podem ser gerados em solução (complexos in-situ). Os complexos ex-situ foram analisados por análise elementar, espectroscopias nas regiões do infravermelho e ultravioleta-visível e voltametria cíclica (em Pt). As eletrólises foram realizadas em substrato de aço 1020 com um ou dois complexos metálicos presentes no banho. Banhos de eletrodeposição de nióbio usando como substrato aço 1020 coberto com Cu e/ou Zn foram bem sucedidos. Os depósitos foram analisados por microscopia eletrônica de varredura (MEV), espectroscopia de dispersão de raios X (EDX), reflectância difusa, espectroscopia de difração de raios X (DRX) e por curvas de polarização anódica (estudos de corrosão). Os banhos com complexos in-situ 10:1 fomeceram depósitos com aspectos morfológicos ruins em relação aos depósitos obtidos de banhos com complexos in-situ 1:5 e ex-situ. As morfologias dos depósitos obtidos dos banhos com acetato foram dendríticos e com baixa aderência. Os depósitos dos banhos com complexos citrato e oxalato foram lisos, compactos, com boa aderência e brilhantes. Diferentes fases estruturais foram observadas nos depósitos e a maioria deles protege contra a corrosão. Os estudos concluíram que os ligantes analisados influenciam diferentemente nos processos de eletrodeposição. / Cu(II), Ni(II), Zn(II) and Nb(V) coordination complexes were obtained with acetate, citrate and oxalate ions as ligands (ex-situ complexes) to be applied in electrodeposition baths. The aim is to use these complexes as metal sources without further addition of additives which are the coordinated ligands. As reference study, electroplating baths with sulfate salts of the metal ions in presence of the ligands were investigated in the metal:ligand ratio of 1:5 and 10:1; then, similar coordination complexes can be generate in solution (in-situ complexes). The ex-situ complexes were characterized by elemental analysis, infrared and UV-vis spectroscopies and cyclic voltammetry (in Pt). The electrolyses were performed in 1020 steel as substrate with one or two metal complexes present in the bath. Niobium electroplating baths with 1020 steel previously covered with Cu and/or Zn as substrates were also successfully performed. The deposits were analyzed by scanning electron microscopy (SEM), energy dispersive spectroscopy X-ray (EDS), diffuse reflectance, X-ray diffraction (XRD) and polarization curves (corrosion studies). The bath with 10:1 in-situ complexes provided deposits with poor morphologic aspects in relation to the deposits obtained from bath with 1:5 in-situ and ex-situ complexes. The morphologies of the deposits obtained from bath with the acetate complexes were dendritics and with low adherence. The bath with both citrate- and oxalate-complexes were smoothes, compacts, with good adherence and brightness. Different structural phases were observed in the deposits and the most of them provided protection against corrosion. It was concluded that coordinated ligands influence differently in the electrodeposition processes.

O desenvolvimento de sensores eletroquímicos para glicose integrados a cateteres tem como requisitos básicos a sua miniaturização e funcionamento por períodos relativamente longos no ambiente intravenoso. A função de tais sensores é o acompanhamento de forma continuada e em tempo real, a evolução clínica de pacientes internados em unidades de terapia intensiva (UTIs). Dentre os sensores para glicose, os biossensores amperométricos baseados na reação enzimática de glicose oxidase se mostrou o mais promissor. Diferentes procedimentos para a construção de tais microssensores implantáveis foram desenvolvidos. Um conjunto de eletrodos, constituído fios de platina (mais adiante cobre, com diâmetro 0,18 mm) e de prata (diâmetro 0,20 mm) revestidos com poli-vinil-formol foram posicionados no interior de uma agulha de aço inoxidável (30,0 mm de comprimento e 0,80 a 1,2 mm de diâmetro) e fixados com resina epóxi, constituindo um dispositivo único com os eletrodos de trabalho, referência e auxiliar, respectivamente. A otimização do sensor envolveu a platinização eletroquímica da superfície do eletrodo de trabalho, o que aumentou a sua área efetiva e favoreceu a deposição do material enzimático. A presença de um detergente não iônico favoreceu a formação de um filme uniforme de enzimas e a eletropolimerização de 1,2-diaminobenzeno (em presença de albumina de soro bovino) foi utilizada para a formação de um filme com a característica de minimizar a interferência de espécies neutras. A adição de um filme de Náfion® à superfície do sensor aumentou a seletividade. O sensor resultante caracterizou-se por possuir um tempo de resposta curto (~6 s), linearidade de 1,0 até 12,5 mmol dm-3 com um limite de detecção de 1,0 mmol dm-3 , diminuição na resposta de espécies eletroativas (ácido ascórbico 2,0% e paracetamol 10,5% em relação à glicose) e uma vida útil superior a sete dias, em tampão fosfato 0,05 mol dm-3 . Para possibilitar o implante de tais sensores, foram exploradas diferentes metodologias de esterilização, sendo a mais favorável a irradiação com acelerador de elétrons com doses acumulativas. Sensores revestidos com acetato de celulose e Náfion® (a melhor condição) apresentaram perda de atividade da ordem de 15%, após serem irradiados. / The development of electrochemical sensors for glucose integrated into catheters has as basic requisite its miniaturization and the requirement of functioning for relatively long periods in the intravenous environment. The function of such sensors is the continuous monitoring on real time of the clinical evolution of patients hospitalized in intensive therapy units (UTIs). Amongst the sensors for glucose, amperometric biosensors based on the enzymatic reaction of glucose oxidase has been considered as the most promising ones. Different procedures for the construction of such microsensors to be implanted have been developed. A set of electrodes, constituted by a platinum wire (along this work, it was substituted by copper wires) with 0.18 mm diameter and a silver wire with 0.20 mm diameter coated with poly-vinyl-formol were positioned inside a stainless needle (30.0 mm length and 0.80 to 1.2 mm diameter) and fixed with epoxy resin, resulting in a single device containing the working, reference and auxiliary electrodes, respectively. The optimization of the sensor involved the electrochemical platinization of the working electrode surface, increasing its effective area and favoring the deposition of the enzymatic material. The presence of a non-ionic detergent favored the formation of a uniform film of enzyme and the electropolymerization of 1,2-diaminobenzene (in the presence of albumin and bovine serum) was used for the formation of a film able to ® interference of neutral species. The addition of a Nafion® film to the sensor surface increased its selectivity. The resultant sensor was characterized for its short time -3 response (~6 s), linearity between 1.0 and 12.5 mmol dm-3 with a detection limit of 1.0 mmol dm-3 , reduction in the interference of electroactive species (2.0% ascorbic acid and 10.5% paracetamol in relation to glucose) and a useful life larger than seven days, in 0.05 mol dm-3 phosphate buffer. To make possible the implantation of such sensors, different methodologies of sterilization were explored, being the most favorable the irradiation with electron accelerator using accumulating doses. Sensors coated with cellulose acetate and Nafion® (the best condition) presented loss of activity (around 15%), after the irradiation.