Poly(pyrrole-3-carboxylic acid)-modified pencil graphite electrode for the determination of serotonin in biological samples by adsorptive stripping voltammetry

Abstract In this study, we have focused on two subjects which are the preparation of a poly(pyrrole-3-carboxylic acid) modified pencil graphite electrode (p(P3CA)/PGE) and the development of a novel sensing strategy for the determination of serotonin (SER) in blood serum and urine samples. This method is based on the electrochemical reduction of oxidation intermediate of SER formed during electrochemical measurements. The characterization of the p(P3CA)/PGE has been performed by cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. The analytical parameters such as linear range (between 0.01 μM and 1.0 μM), detection limit (2.5 nM according to S / N  = 3) and reproducibility (RSD: 3.8% for N : 10) have also been determined. The effects of different substances on the determination of SER have been investigated. The proposed novel sensing method has been successfully tested for the first time in the determination of SER in human blood serum and urine samples.