Electrochemical Detection of Neurotransmitters Using Modified PEDOT Electrodes

Abstract

This paper presents recent results from authors’ labs on the electrochemical detection of ascorbic acid (AA), serotonin (5-HT) and dopamine (DA) at poly[3,4-ethylenedioxythiophene], PEDOT, and PEDOT-Au electrodes. We could show that the technique used for preparing the PEDOT and the PEDOT-Au electrodes strongly affects the quality of the sensors. Pulse plating gave the best films with regard to their morphology and charge storage. Parameters of the pulse sequence, such as anodic and cathodic potentials, as well as pulse duration, were optimized. Acoustic impedance data (obtained by an Electrochemical Quartz Crystal Microbalance in dispersive mode) show that such films prepared by pulse plating display also maximal elastic storage and loss moduli. The detection limits for the above mentioned neurotransmitters were studied by differential pulse voltammetry in phosphate buffer solution, PBS (Fig. 1), in the presence and absence of AA. Compared to pristine PEDOT, the Au modified electrodes showed a considerable increase of sensitivity and selectivity for neurotransmitters detection. Fig. 1. The DPV curves measured in PBS with different concentrations of (a) 5-HT and (b) DA, on PEDOT layers in the presence of 300μM AA Figure 1