Determinação de catequinas por eletrodo de carbono impresso modificado com nanotubo de carbono funcionalizado

Abstract

Catechin is a phenolic compound with high oxidizing potential, found in several types of foods, some of the benefits of catechins are capillary strengthening, improvement of blood flow and reduction of cholesterol levels. In this paper, it was used the cyclic voltammetry technique (CV) to optimize the printed carbon electrode modified with carbon nanotube, functionalized to detect and quantify catechin by means of the squarewave voltammetry technique (SWV). For this electrode, the best results were obtained at a catechin concentration of 1x10-3 mol L-1 in means of 0.1 mol L-1 phosphate buffer pH 7.0 at a potential scan rate of 0.05 V s-1. From these conditions, an analytical curve was obtained with a linear behavior in the catechin concentration range of 1,68x10-5 to 2,0x10-7 mol L-1, with limits of detection and quantification of 9,2x10-8 and 3,0x10-7 mol L-1, respectively, by SWV. This electrode showed good repeatability with a standard deviation of 4.05%. Oxidation of catechin showed a peak located around 0,15V vs Ag / AgCl, being close to the peak potentials shown in the literature.