Desenvolvimento de dispositivos eletroquímicos descartáveis para detecção de vitamina D

• Autor(a) principal: Venancio, Kamylla de Paula
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/12002
• topic: Desenvolvimento; Dispositivos eletroquímicos; Descartáveis; Detecção; Vitamina D; Development; Electrochemical devices; Disposable; Detection; Vitamin D; CIENCIAS EXATAS E DA TERRA::QUIMICA

Vitamin D deficiency and insufficiency is emerging as a public health problem worldwide, which has resulted in a high demand for clinical tests for its detection and quantification. Given this scenario, the development of electrochemical devices is an alternative for the detection of vitamins, due to its simplicity, low cost, miniaturization and portability. In the present project, a disposable electrochemical device was developed to detect vitamin D in its two forms, Ergocalciferol (D2) and Cholecalciferol (D3). For its development, the device underwent a series of optimizations to guarantee its better functioning, which include its manufacturing process, conditions of use, methodologies and techniques used for detections. After manufacturing optimization, solvents, support electrolytes and parameters that conferred better electrochemical responses were investigated, where in such steps it was defined the use of a mixture of 60% ethanol/water and NaClO4, composing the electrolyte solution, together with vitamins D2 and D3. Voltammetric parameters such as potential increment, sweep speed, amplitude and frequency, most suitable for each vitamin, were evaluated, which made it possible to detect the two forms of vitamin D, at potentials between +0.80 V and 1.0 V. The effect of adsorptive polarization was also evaluated, which allowed the displacement of the oxidation potential to lower values. The proposed methodology proved to be a good alternative to commonly known detection methods, despite having problems such as reproducibility, in part related to the manual manufacturing process of the electrodes and the lipophilic character of the analyte. On the other hand, the use of electrodes offers advantages such as fast, simple and cheap analysis. Selectivity studies were also carried out in the presence of other vitamins, observing a decrease in the peak current of vitamin D. The reproducibility of the device can be increased by automating the production of electrodes and the evaluation of other experimental conditions, such as surface treatment using alkaline medium.