Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-06-14T11:29:23Z No. of bitstreams: 1 taimarapolidoroferreira.pdf: 1182886 bytes, checksum: a5d4b3b0f39cb3072c8ac7463931f8e7 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-13T14:03:33Z (GMT) No. of bitstreams: 1 taimarapolidoroferreira.pdf: 1182886 bytes, checksum: a5d4b3b0f39cb3072c8ac7463931f8e7 (MD5) / Made available in DSpace on 2016-07-13T14:03:33Z (GMT). No. of bitstreams: 1 taimarapolidoroferreira.pdf: 1182886 bytes, checksum: a5d4b3b0f39cb3072c8ac7463931f8e7 (MD5) Previous issue date: 2016-02-25 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A análise de metais em diversos tipos de amostras, já é algo bem descrito na literatura utilizando a espectrometria de absorção atômica, que é a técnica mais popular para este tipo de análise, entretanto o desenvolvimento de técnicas eletroanalíticas para a análise de metais é algo que vem crescendo nos últimos anos. As técnicas eletroanalíticas apresentam as vantagens de conseguirem determinar baixas concentrações de metais, permitirem a determinação simultânea destes e ainda possuírem um baixo custo se comparada à técnicas espectrométricas. Devido ao aumento da preocupação da qualidade dos metais para a confecção de bijuterias, a análise de metais se torna extremamente importante uma vez que altas concentrações desses metais no organismo, em especial metais tóxicos como cádmio e chumbo, podem trazer malefícios irreversíveis para a saúde. Neste contexto, o objetivo do trabalho foi analisar cádmio e chumbo em amostras de bijuterias por voltametria de pulso diferencial (VPD) com etapa de pré-concentração e comparar com as análises por espectrometria de absorção atômica com chama (F AAS). Os parâmetros utilizados para a análise por voltametria de pulso diferencial foram: o potencial de deposição de -0,9 V com duração de 120 s e a faixa de potencial de -0,9 a 0,1 V. Dois tipos de digestão para as amostras foram testadas, em chapa de aquecimento e em um equipamento de micro-ondas, e após as digestões, as amostras foram analisadas pelas duas técnicas. A digestão por micro-ondas se mostrou mais adequada, assim como as análises por voltametria que apresentaram boa exatidão, que foi avaliada através de estudos de adição e recuperação, com resultados entre 99 a 110% para o cádmio e 99 a 105% para o chumbo. As amostras de bijuterias analisadas pela VPD e digeridas por micro-ondas continham de < LD a 4,05 % m/m de cádmio e de 0,004 a 7,55 % m/m de chumbo. Os limites de detecção foram de 0,75 mg L-1 para o cádmio e de 0,07 mg L-1 para o chumbo para a técnica de absorção atômica e os limites de detecção para a voltametria foram de 0,02 mg L-1 para o cádmio, e de 2,26.10-3 mg L-1 para o chumbo. / The metal analysis of various types of samples, using atomic absorption spectrometry, is well described in the literature. It is the most popular technique for this type of analysis; however the development of electroanalytical techniques for the analysis of metals has been growing in recent years. The electroanalytical techniques have the advantages of be able to determine low concentrations of metals, allow the simultaneous determination of these and have low cost compared to spectrometric techniques. Due to the increased concern for quality of metals for the manufacture of jewelry, the metal analysis is extremely important since high concentrations of these metals in the body, in particular toxic metals such as cadmium and lead can bring irreversible harm to health. In this context, the aim of this study was to analyse cadmium and lead in jewelry samples by differential pulse voltammetry (DPV) with pre-concentration step and compare the results with atomic absorption spectrometry with flame (F AAS). The parameters used for the analysis by differential pulse voltammetry were: deposition potential = -0.9 V, deposition time = 120 s and the potential range from -0.9 to 0.1 V. Two types of samples digestion were tested: hot plate and microwave equipment. After digestions, the samples were analyzed by both techniques (DPV and F AAS). Digestion by microwave proved most suitable, as well as voltammetry results that showed good accuracy, which was evaluated by adding and recovery studies with results from 99 to 110% for cadmium and 99 to 105% for lead. Samples of jewelry and analysed by the DPV digested microwave contained the <LOD to 4.05 % w / w cadmium and 0.004 to 7.55 % w / w of lead. The limits of detection were 0.75 mg L-1 for cadmium and 0.07 mg L-1 for lead for atomic absorption technique and limits of detection for voltammetry was 0.02 mg L-1 for cadmium, and 2.26.10-3 mg L-1 for lead.

Anilazine (4,6-dichloro-N-(2-chlorophenyl)-1,3,5-triazin-2-amine) is a fungicide from a group of triazine pesticides. These have been very widely used but for their toxicity for water environment they are being cancelled. Use of anilazine is not allowed anymore in the European Union. However, traces of its residues are able to find in environmental samples. The diploma thesis deals with determination of anilazine using silver solid amalgam electrode modified by mercury meniscus (m-AgSAE). Differential pulse voltammetry was used. For the determination, an acidic solution is necessary. In the work Britton-Roninson buffer pH = 2 was used. This is because of electrochemical reduction of anilazine (and other triazines) which is started by protonization of heterocycle ring. Anilazine exhibits one single well-defined peak, the potential of the peak was about Ep = -827 mV (vs. 3 mol l-1 argentochloride electrode). The limit of quantification achieved in surface water was 2 µmol.l-1. Other two possibilities of getting lower limit of quantification were examined - Adsorptive Stripping Voltammetry (AdSV) and preconcentration by Solid Phase Extraction (SPE). Using AdSV the limit of quantification LQ = 0,5 µmol.l-1. Conditions of adsorption were as following: Eacc = -100 mV, tacc = 60 s. For SPE, 200-mg columns...

La technique de l’impression moléculaire permettant d'obtenir des polymères hautement sélectifs est utiliséedans de nombreuses applications. Dans le cadre de cette thèse, cette technique est employée pour préparer despolymères spécifiques du benzo(a)pyrène (BaP) en vue d’une application capteur. L’introduction d’une sonderédox au sein même du réseau de polymère offre la possibilité d’une détection directe de la cible, par unetechnique électrochimique. Dans le domaine des MIPs, ce travail est le premier à décrire l’utilisation d’unmonomère participant à la formation du réseau tridimensionnel tout en apportant une propriété rédox. Lespolymères synthétisés par polymérisation par précipitation ont été caractérisés en termes de composition, destabilité thermique et de propriétés texturales. Les propriétés de rétention ont été évaluées en mode batch parHPLC-UV en présence de BaP et d'interférents de type hydrocarbures aromatiques polycycliques. Ces MIPsprésentent de bonnes propriétés d’adsorption vis-à-vis du BaP avec des facteurs d’empreinte supérieurs à 1montrant l’efficacité de l’impression. Ces propriétés sont conservées en présence d’une matière organique (seld’acide humique), mais également après plusieurs cycles d’utilisation. Les analyses électrochimiques ontdémontré que les propriétés électrochimiques de ces MIPs diffèrent selon la présence ou pas de la cible avecune limite de détection de 0,09 μM en BaP, ouvrant la porte à la réalisation de capteurs. / Molecularly Imprinted Polymers show highly selective affinity towards the target molecule and are used inmany applications. In this context, the technology is used for preparing selective polymers for benzo(a)pyrene(BaP) with the aim of sensor fabrication. The addition of a redox tracer inside the polymer allows thepossibility of direct target detection by an electrochemical technique. In the MIP field, this work is the firstreporting the use of a functional monomer that not only participates in the creation of the polymer network butalso provides a redox property. The polymers synthesized using precipitation polymerization technique werecharacterized in terms of composition, thermal stability and textural properties. The adsorption properties wereevaluated in batch mode by HPLC-UV in the presence of BaP and interfering polycyclic aromatichydrocarbons. These MIPs show good adsorption behavior towards BaP with imprinting factors superior to 1showing the efficiency of the molecular imprinting. These properties were also preserved even in presence ofan organic matter (humic acid salt), and also after several uses. Finally, electrochemical analysis showed thatthese MIPs had a different electrochemical behavior depending on the presence or the absence of the targetwith a detection limit of 0.09 μM for BaP. The use of such electrochemical MIPs can thus be interestinglyconsidered in sensor devices.

Made available in DSpace on 2014-12-17T15:42:17Z (GMT). No. of bitstreams: 1 SeverinaDSO_DISSERT.pdf: 2512071 bytes, checksum: 12a15e7529d5b018959d5e9c644f10cf (MD5) Previous issue date: 2013-07-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this work a study was done using electrochemical cyclic voltammetry and differential pulse voltammetry for isoniazida (INH), ethambutol (EMB), rifampicina (RIF) and pyrazinamide (PZA) using the electrode boron-doped diamond (BDD) as working electrode. It also verified the applicability of the technique of differential pulse voltammetry in the quantification of the active compounds used in the treatment of tuberculosis, subsequently applying in samples of pharmaceutical formulation. Among the four active compounds studied, isoniazid showed the best results for the detection and quantification using differential pulse voltammetry. At pH 4 and pH 8, for the calibration curves to INH showed good linearity, with quantification limits of 6.15 mmol L-1 (0,844 ppm) and 4.08 mmol L-1 (0.560 ppm) for the respective pH. The proposed method can be used to determine drug isoniazid, for recovery values were obtained in approximately 100% / Neste trabalho foi feito um estudo eletroqu?mico utilizando a voltametria c?clica e voltametria de pulso diferencial para os f?rmacos isoniazida (INH), etambutol (EMB), rifampicina (RIF) e pirazinamida (PZA) usando o eletrodo de diamante dopado com boro (BDD) como eletrodo de trabalho. Foi tamb?m verificado a aplicabilidade da t?cnica de voltametria de pulso diferencial na quantifica??o dos princ?pios ativos usados no tratamento da tuberculose, posteriormente aplicando em amostras de formula??o farmac?utica. Dentre os quatro princ?pios ativos estudados, a isoniazida apresentou os melhores resultados de detec??o e quantifica??o com o uso da voltametria de pulso diferencial. Em pH 4 e pH 8, as curvas de calibra??o para a INH apresentaram boa linearidade, apresentando os limites de quantifica??o de 6,15 &#956;mol L-1 (0,844 ppm) e 4,08 &#956;mol L-1 (0,560 ppm), para os respectivos pH. O m?todo proposto pode ser usado para a determina??o de isoniazida em f?rmacos, pois foram obtidos valores de recupera??o em torno de 100%

Made available in DSpace on 2014-12-17T15:42:30Z (GMT). No. of bitstreams: 1 ElianeGA_TESE.pdf: 3715497 bytes, checksum: 52c61110127824acc91be76b2127151f (MD5) Previous issue date: 2013-12-04 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The development of more selective and sensitive analytical methods is of great importance in different areas of knowledge, covering, for example, food, biotechnological, environmental and pharmaceutical sectors. The study aimed to employ the technique electroanalytical differential pulse voltammetry (DPV) as an innovative and promising alternative for identification and quantification of organic compounds. The organic compounds were investigated in this study oxalic acid (OA) and folic acid (FA). The electrochemical oxidation of oxalic acid has been extensively studied as a model reaction in the boundary between the organic and inorganic electrochemistry. Since the AF, an essential vitamin for cell multiplication in all tissues, which is essential for DNA synthesis. The AF has been investigated using analytical techniques, liquid chromatography and molecular absorption spectrophotometry. The results obtained during the experimental procedure indicated that the process of electrochemical oxidation of oxalic acid is strongly dependent on the nature of the anode material and the oxidation mechanism, which affects their detection. Efficient removal was observed in Ti/PbO2 anodes, graphite, BDD and Pt 90, 85, 80 and 78% respectively. It was also shown that the DPV employing glassy carbon electrode offers a fast, simple, reliable and economical way to determine the AO during the process of electrochemical oxidation. Furthermore, electroanalytical methods are more expensive than commonly used chromatographic analysis and other instrumental methods involving toxic reagents and higher cost. Compared with the classical method of titration and DPV could be a good fit, confidence intervals and detection limits confirming the applicability of electroanalytical technique for monitoring the degradation of oxalic acid. For the study of AF was investigated the electrocatalytic activity of the carbon paste electrode for identification and quantification in pharmaceutical formulations by applying the DPV. The results obtained during the experimental procedure showed an irreversible oxidation peak at 9.1 V characteristic of FA. The carbon paste sensor showed low detection limit of 5.683?10&#8722;8 mol L-1 reducing matrix effects. The spectrophotometric analysis showed lower concentrations of HF compared with those obtained by HPLC and DPV. The levels of AF were obtained according to the methodology proposed by the Brazilian Pharmacopoeia. The electroanalytical method (DPV) proposed is cheaper than GC analysis commonly used by the pharmaceutical industry. The results demonstrated the potential of these electroanalytical techniques for future applications in environmental, chemical and biological sensors / O desenvolvimento de m?todos anal?ticos cada vez mais seletivos e sens?veis ? de grande relev?ncia em diferentes ?reas do conhecimento, contemplando, por exemplo, os setores aliment?cios, biotecnol?gicos, ambientais e farmac?uticos. O estudo teve como objetivo empregar a t?cnica eletronal?tica voltametria de pulso diferencial (DPV) como uma alternativa inovadora e promissora para identifica??o e quantifica??o de compostos org?nicos. Os compostos org?nicos investigado neste estudo foram o ?cido ox?lico (AO) e o ?cido f?lico (AF). A oxida??o eletroqu?mica do ?cido ox?lico tem sido extensivamente estudada como uma rea??o modelo na fronteira entre a eletroqu?mica org?nica e inorg?nica. O AF ? uma vitamina essencial na multiplica??o celular de todos os tecidos, indispens?vel ? s?ntese do DNA, tem sido investigada empregando t?cnicas anal?ticas, com a cromatografia l?quida e a espectrofotometria de absor??o molecular. No presente trabalho foi investigada a oxida??o eletroqu?mica do AO em diferentes materiais eletrocatal?ticos. Os resultados obtidos durante o procedimento experimental indicaram que o processo de oxida??o eletroqu?mica do ?cido ox?lico ? depende fortemente da natureza do material an?dico e do mecanismo de oxida??o, o que afeta a sua detec??o. Eficientes remo??es foram obtidas em ?nodos de Ti/PbO2, grafite, BDD e Pt 90, 85, 80 and 78% respectivamente. Foi tamb?m demonstrado que a VPD empregando eletrodo de carbono v?treo oferece uma maneira r?pida, simples, confi?vel e econ?mica para determinar a AO durante o processo de oxida??o eletroqu?mica. Al?m disso, os m?todos eletroanal?ticos s?o mais baratos do que a an?lise cromatogr?fica comumente utilizada e que outros m?todos instrumentais envolvendo reagentes t?xicos e de custo mais elevado. Comparado com o m?todo de titula??o cl?ssica e DPV conseguiu-se um bom ajuste, intervalos de confian?a e limites de detec??o confirmando a aplicabilidade da t?cnica eletroanal?tica para o monitoramento da degrada??o de ?cido ox?lico. Para o estudo envolvendo o AF foi investigado a atividade eletrocatal?tica do eletrodo de pasta de grafite para a sua identifica??o e quantifica??o em formula??es farmac?uticas aplicando a VPD. Os resultados obtidos durante o procedimento experimental indicaram um pico de oxida??o irrevers?vel em 9,1 V caracter?stico do AF. O sensor de pasta de grafite apresentou baixo limite de detec??o 5,683?10&#8722;8 mol L-1 reduzindo os efeitos da matriz. As an?lises espectrofotom?tricas apresentaram concentra??es de AF menor quando comparadas com os dados obtidos por CLAE e VDP. Os teores de AF foram obtidos de acordo com a metodologia proposta pela farmacopeia brasileira. O m?todo eletroanal?tico (VPD) proposto apresenta menor custo e redu??o do tempo de an?lise, quando comparado com a cromatografia l?quida, t?cnica comumente utilizadas pelas ind?strias farmac?uticas. Os resultados demonstraram o potencial dessas t?cnicas eletroanal?ticas para futuras aplica??es em sensores ambientais, qu?micos e biol?gicos

Made available in DSpace on 2016-08-19T12:56:29Z (GMT). No. of bitstreams: 1 CRISTIANE SOUSA MENDES pdf.pdf: 694969 bytes, checksum: e48bc786539dbcfeb903781ae8fef3ca (MD5) Previous issue date: 2007-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work present an evaluation of a modified glassy carbon electrode with NiTSPc immobilized with film PLL of the determination of paraquat by differential pulse voltammetry. The film was formed applying 20μL of a solution prepared for the mixture of equal volume of NiTSPc 0,8mM and poly-L-lisine (PLL) 0,12mM. The maximum signal to noice ratio was obtained using a 0,1M Britton-Robinson buffer at pH=7,0 as supporting electrolyte.. The electrode modified with NiTSPc/PLL presented PQ reduction currents more accented and voltammetrics profiles better with respect to the electrodes unmodified and modified with CuTSPc/PLL. The best conditions of analyze had been amplitude of pulse 125mV, width of pulse 25mV, speed of sweepings 10mV/s. The maximum relation signal noise was gotten in drain plug Britton-Robinson 0,1M, with pH 7,0 as electrolyte has supported. This sensor presented two reversible peaks for reduction of the PQ around - 0.71 V (peak 1) and - 1,10 V (peak 2) versus E.C S. In these conditions, the modified electrode obtained a linear response range from 1,00 x 10-6 to 1,00 x 10-5 mol L-1 with detection and quantification limits equals to 7,58 x 10-8 mol L-1 (19,5 μg L-1) and 2,5 x 10-7 mol L-1 (64 μg L-1), respectively. The studied sensor presented values below 5%, in terms of relative standard deviation, for repeatability (2,52% for N = 10) and reproducibility (2,97% for N = 5) studies. The recovery in real samples was of 98%. / Este trabalho apresenta uma avaliação de um eletrodo de carbono vítreo modificado com NiTSPc imobilizada com filme de poli-L-lisina para determinação do paraquat por voltametria de pulso diferencial. O filme foi formado adiconando-se 20μL de uma solução preparada pela mistura de volumes iguais de NiTSPc 0,8mM e PLL 0,12mM. O eletrodo modificado com NiTSPc/PLL apresentou correntes de redução do PQ mais acentuadas e melhores perfis voltamétricos em relação ao eletrodo não modificado e modificados com CuTSPc/PLL. As melhores condições de analise foram amplitude de pulso 125mV, largura de pulso 25mV, velocidade de varredura 10mV/s. A máxima relação sinal ruído foi obtida em tampão Britton-Robinson 0,1M, com pH 7,0 como eletrólito suporte. Este sensor apresentou dois picos reversíveis para redução do PQ em torno de - 0,71 V (pico 1) e - 1,10 V (pico 2) vs E C S.. Nestas condições, o eletrodo modificado obteve uma resposta linear de 1,00 x 10-6 a 1,00 x 10-5 mol L-1 com limites de detecção e quantificação iguais a 7,58 x 10-8 mol L-1 (19,5 μg L-1) e 2,5 x 10-6 mol L-1 (64 μg L-1), respectivamente. O sensor estudado apresentou valores abaixo de 5%, em termos de desvio padrão relativo, para estudos de repetibilidade (2,52% para N = 10) e reprodutibilidade (2,97% ....para N = 5). A recuperação em amostras reais foi de 98%.

This thesis is focused on the application of two working electrodes of graphite suitable for determination of oxidizable tumour biomarkers. It deals with the study of electrochemical behavior of urinary indican. For the determination the technique of differential pulse voltammetry (DPV) was used on carbon paste electrode and film composite paste electrode in Britton-Robinson (BR) buffer. In the first step optimal conditions were determined to find the lowest limit of determination (LQ) of this substance. BR buffer of pH 3 was chosen as the optimum medium for determination on a carbon paste electrode and BR buffer of pH 2 was used as the optimum medium for the determinaton using a film composite electrode. Performance for both electrodes was observed in a concentration range of from 1 · 10-6 to 5 · 10-5 mol·l-1 . The limit of determination for measurements on a carbon paste electrode was 0.7 µmol·l-1 and the film composite electrode was 1.7 µmol·l-1 . Possibility of the acummulation of indican was examined in order to increase sensitivity and decrease of limit of quantification. However, after 5 minute sorption, no increase in response was observed and the accumulation step was not inserted. Developed method was tested on the determination of urinary indican in human urine matrix after solid phase...

>Magister Scientiae - MSc / Tuberculosis (TB) is a disease that results from infection by Mycobacterium tuberculosis, which is regarded the most common infecting organism. TB has killed countless numbers of people particularly in underdeveloped countries. TB bacteria can remain inactive or in dormant state for years without causing symptoms or spreading to other subjects, but as soon as the immune system of the host becomes weakened, the bacteria become active and infect mainly the lungs along with other parts of body. TB cases are further aggravated by other illnesses that affect the immune system, such as human immune virus (HIV), which is very prevalent in resource-poor countries. Interferon-gamma (IFN-γ) is a TB biomarker that has found to have all the qualities that are needed to help and cure Tuberculosis disease. Early diagnosis and treatment are essential measures for effectively controlling the disease. Traditional microbial culture-based tests are the most common methodologies currently used. Usually, these methods involve cell culture, cell counts, and cell enrichment, but this process is time-consuming and laborious, especially for the slow-growing bacteria like M. tuberculosis. Sputum smear is one of the methods currently used to detect acid fast bacilli (AFB) in clinical specimens or fluorescent staining. It is a cost-effective tool for diagnosing patients with TB and to monitor the progress of treatment especially in developing countries. The traditional method of inoculating solid medium such as Lowerstein-Jensen (L-J) or 7H10/7H11 media is also used currently it is slow and takes 6-8 weeks of incubation to diagnose the infection and further more time to determine the susceptibility patterns. The microscopic observation drug susceptibility (MODS) assay they are also used currently they rely on light microscopy to visualize the characteristic cording morphology of M. tuberculosis in liquid culture. MODS has shorter time to culture positivity (average 8 days) compared with LJ medium (average ~26 days), they are very expensive. The Gen-Probe assay specific for M. tuberculosis complex is a rapid detection that is also used, nucleic acid amplification (NAA) test results can be obtained as fast as in two hours (provided if a positive culture is present); it also has a high sensitivity of 99% and specificity of 99.2%. It holds the disadvantage of needing of positive culture that can take several days. Enzyme-linked immunosorbent assay (ELISA), is a test that uses antibodies and colour change to identify a substance. ELISA is an assay that uses a solid-phase enzyme immunoassay (EIA) to detect the presence of a substance, usually an antigen, in a liquid sample or wet sample. It can be used to detection of Mycobacterium antibodies in tuberculosis. The Amplified Mycobacterium Tuberculosis Direct Test (AMTDT) is used for the detection of M. tuberculosis it enables the amplification and detection of M. tuberculosis rRNA directly from respiratory specimens. The diagnostic methods employing genetechnology based on the amplification of DNA or RNA are expected to improve the speed, sensitivity, and specificity of Mycobacterium tuberculosis detection. TB rapid cultivation detection technique, such as MB/BacT system, BactecMGIT 960 system and flow cytometry. The BACTEC MGIT960 system (Becton Dickinson, Sparks, MD) performs incubation and reading of the tubes continuously inside the machine using a predefined algorithm to interpret the fluorescent signal and giving the results as positive or negative. When performing DST, the BACTEC MGIT960 interprets the results as susceptible or resistant to the antibiotic under study. Results are available within 8 days. A recent meta-analysis of the published studies found high accuracy and high predictive values associated with the use of BACTEC MGIT960. These methods are more sensitive and rapid than the traditional microbial culture-based methods. However, they cannot provide the detection results in real-time and most of these methods are centralized in large stationary laboratories because complex instrumentation and highly qualified technical staff are required. Recently, Food and Drug Administration (FDA) approved two new assays that were introduced. These two assays detect in vitro a specific immune response to M. tuberculosis. These tests are the QuantiFERON-TB Gold In-Tube (Cellestis/Qiagen, Carnegie, Australia) and the T-SPOT.TB assay (Oxford Immunotec, Abingdon, United Kingdom). Both assays use whole blood from the patient and measure the production of interferon gamma after the whole blood is exposed to specific antigens from M. tuberculosis. These tests are based on the knowledge that IFN-γ is a product of an active cell-mediated immune response induced by M. tuberculosis. However, TB detection remains a major obstacle due to several drawbacks of these methods. To date, the number of diagnosis approaches for TB has increased as the disease continues to be a major public health problem worldwide and most conventional detection technologies present difficulties in recognizing the presence of M. tuberculosis, since they are time consuming, do not provide clinically reliable results and significantly lack of sensitivity. This thesis focusedon developing two binary and one ternary-electrochemically quantum dots, all synthesised at room temperature in aqueous media for detecting (IFN-γ). Copper telluride (CuTe) and Zinc telluride (ZnTe) was prepared to check how does the two quantum dot behave individual and also to check on how they behave when they are combined and formed ternary quantum dots (CuZnTe). The electrochemical studies of the binary CuTe quantum dots, ZnTe quantum dots and the ternary CuZnTe core-shell quantum dots reveal that ternary quantum dots were stable and showed a significant enhancement in the conductivity of CuZnTe core-shell solution compared to that of CuTe and ZnTe, all studied in solution. The three different quantum dots were capped with three different capping reagents which are tetraethyl orthosilicate (TEOS), thioglycolic acid (TGA), (3-mercaptopropyl) trimethoxysilane (MPS). In the study, a label-free electrochemical immunosensor for the detection of interferon gamma (IFN-γ) was prepared for the first time using ternary quantum dots. The biosensor consists of water-soluble silica coated Copper Zinc telluride (CuZnTe core-shell) quantum dots conjugated to a gold electrode. The antibody-antigen were then conjugated on the CuZnTe core-shell QD modified gold electrode. Results from synthesis of two different binary quantum dots are also presented in the study and compared to the results of the CuZnTe core-shell QDs. The CuTe quantum dots had a small average size which was confirmed through HRTEM, SAXS and XRD analysis

Aim of this thesis is voltammetric study influence of liposomal platinum cytostatics on cancer cells. One of the goals is summarize available informations about influence of cisplatine on cancer cells, its encapsulation into liposome and affection of this cytostatic cisplatin encapsulated in liposome on cancer cell lines. In literary recherche is detail description of these issues. Than is there specification of voltammetric methods, which serve to electrochemical detection of cisplatin. Based on literary recherche was chosen the best method for detection and subsequently the method was optimalized and than was applied to measuring itself.

Voltammetric methods for the determination amphenicol antibiotic chloramphenicol (CAP) and quinolone antibiotic Ofloxacin (OFL) were developed. TTechniques differential pulse voltammetry (DPV) and DC voltammetry (DCV) for determination of both substances at boron doped diamond film electrode (BDDFE) were used. The effect of pH of Britton-Robinson buffer was tested and the stability of the signal with repeated measurements was monitored. Optimal pH 6 was used for determining of CAP by both, DPV and DCV techniques. Media of pH 4 for determining of OFL by DPV and DCV was optimal. Under these conditions linear dependences in the calibration concentration region 1.10 -6 - 1.10-4 mol.l -1 were obtained. The limit of determination for the method for CAP by DPV at 3.10 mol.l , by -6 -1 DCV at 3.10 mol.l and for -6 -1 OFL by DPV at 1.10 mol.l -6 -1 and by DCV at 4.10 mol.l -7 -1 was found. The developed methods were used for the determination of CAP in the drug samples Spersadex comp. and OFL determination in drug samples Zanocin 200. Method for solid phase extraction of OFL from samples of urine with voltammetric detection was developed with limit of determination at 7.10 mol.l . -6 -1