Avaliação de diferentes nanotubos de carbono de paredes múltiplas e alumina para a determinação de clorexidina

Abstract

This work presents the investigation of modified electrodes for the electrochemical determination of chlorhexidine, an active substance in commonly used antiseptics. For this, the modified carbon glassy electrode modified with multi-walled carbon nanotubes (MWCNT) of different sizes and with alumina were chosen and the results compared with unmodified electrode. Cyclic voltammetry was used for initial investigation of the electrochemical processes and it was found that modified electrodes, in general, increase the current signal of the oxidation process of chlorhexidine. The amperometric detection was coupled to the batch injection system (BIA) to evaluate the amperometric determination of chlorhexidine. It was observed that the modified electrodes reduce the adsorption effects of the analyte, extended the linear range, and decrease detection limits in relation to the clean electrode. In general, the most satisfactory results regarding the analytical characteristics of the method were obtained with the modified MWCNT electrode of smaller size and not functionalized; however, the results with the electrode modified with alumina, a low-cost material not commonly used for this purpose, were also satisfactory.