Optimization of the DPV potential waveform for determination of ascorbic acid on PEDOT-modified electrodes

The electrocatalytic behaviour of poly(3,4-ethylendioxythiophene) (PEDOT) is investigated with respect to detection of ascorbic acid (AA), due to the fundamental importance of such analyte, both for pharmaceutical and food applications. The comparison of the response obtained with ascorbic acid on PEDOT-modified electrodes with Pt-unmodified electrodes resulted particularly interesting: A significant electrocatalytic effect ascribable to the conducting polymer is documented by an anticipated oxidative response of AA, accomplished by a noticeable increase of the anodic peak current. Differential pulse voltammetry (DPV) has been employed as technique for the evaluation of the performance of the CME. The effects of DPV scan parameters on the response of the CME have been studied by means of a 3 factors and 3 levels experimental design. These investigations allowed us to individuate the scan parameters leading to optimal response of the device. The response of CME for AA has been studied by DPV in the optimised conditions, showing good performance in terms of sensitivity and detection limit. A study on the effect of the thickness of the coating has been conducted. The effect of the pH of the solution on the CME response has been also studied.