DESENVOLVIMENTO DE SENSORES NANOESTRUTURADOS PARA A CONSTRUÇÃO DE UMA LÍNGUA ELETRÔNICA PARA A AVALIAÇÃO DE VINHOS

• Ano de defesa: 2014
• Autor(a) principal: Silva Júnior, Elvandi da
• Orientador(a): Bulhões, Luis Otávio de Sousa
• Banca de defesa: Carvalho, Leandro Machado de, Salazar, Rodrigo Fernando dos Santos
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Centro Universitário Franciscano
• Programa de Pós-Graduação: Programa de Pós-Graduação em Nanociências
• Departamento: Biociências e Nanomateriais
• País: Brasil
• Palavras-chave em Português: eletrodo de pH, eletrodo de compostos fenólicos, medidas potenciométricas, medidas potenciodinâmicas.
• Palavras-chave em Inglês: pH electrode, phenolic compounds electrode, potentiometric measurements, potentiodynamic measurements
• Área do conhecimento CNPq: Biociências e Nanomateriais
• Link de acesso: http://www.tede.universidadefranciscana.edu.br:8080/handle/UFN-BDTD/532

The wine win more consumers in Brazil day-by-day, due to increased quality and association of daily use of small doses to health benefits. The perception and increase the quality of the product are given by their organoleptic properties and the advances in its manufacturing process. Some equipments are used by professionals involved in the production of wine, such as assistance with obtaining data and physicochemical properties during the process. The need to use multiple measurement equipment during the processing procedure leads to loss of time and convenience. In order to possible an alternative to minimize these matters an equipment has been developed and tested employing nanostructured sensors detectors involving metal/oxide interface to evaluate the pH of wine and phenolic compounds. These systems were obtained by chemical and electrochemical techniques, and the evaluation of their performance was done by using potentiometric or potentiodynamic measurements. An electronic system was developed to acquire and process data in real time. Tests have shown that among the electrodes developed and tested pH electrode with composition the was Ir0,3Ti0,7O2 system that showed the best linear response with a sensitivity of 57.6 mV/pH in the pH region of 2-8, with excellent agreement with Nerstiniana response expected for this system (59.16 mV/pH). The copper electrodes anodized at 2 V for 30 min, sensitive to the amount of caffeic acid in aqueous solutions of 0.1 M NaOH. The responses observed in voltammograms indicate inhibition of cathodic solutions with the addition of 1 mL of wine and the increase in oxidation current at 0.7 V, which is associated with the oxidation of phenolic compounds. Using the current associated with this process, it was possible to classify the sample by phenolic content of wine. At the end, the nanostructured proved feasible to determine the pH and phenolic compounds in wine samples.