Electrochemical Sensor Based on a Cyclodextrin Modified Carbon Paste Electrode for Trans-Resveratrol Analysis

Resveratrol, a phenolic phytoalexin, shows a variety of biological activities such as protection against cardiovascular diseases and atherosclerosis. In recent years it has gained an upswing in its popularity due to the so called "French paradox". In this connection a novel electrochemical sensor based on cyclodextrin modified carbon paste electrodes was designed and investigated for detecting transresveratrol in grape samples. The cyclodextrin modified electrodes show significant activity in the presence of resveratrol when applying differential pulse voltammetry. Under optimized conditions using alpha-cyclodextrin as modifier a well defined voltammetric peak appeared at about +450 mV vs. Ag/AgCl in a methanolic Britton-Robinson buffer solution (1:1; v/v). The peak height of the resveratrol current signal increased linearly in the concentration range of 30 - 1000 mu g/L (R= 0.998). The limit of detection (LOD) was determined to be 12 mu g/L. The modified electrode was successfully employed to determine resveratrol in complex grape material.