Development and Application of the Serotonin Voltametric Sensors Based on Molecularly Imprinting Technology

Abstract

A novel modified glassy carbon electrode was prepared as an electrochemical voltammetric sensor based on molecularly imprinted polymer film for serotonin detection. The sensitive film was prepared by co-polymerization of 5-hydroxy tryptophan (5-HTP) and acrylamide (AM) on the carbon nanotubes modified glassy carbon electrode. The surface morphologies of the modified electrodes were characterized by scanning electron microscope. The electrochemical behavior of serotonin molecules on the imprinted electrode was studied by differential pulse voltammetry (DPV), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under the optimum conditions, the linear relationships between current and concentration were obtained in the range from 1.8 × 10−6 to 5.4 × 10−9 mol L−1, with the linear regression equation Ip = 1.552 C + 8.778 × 10−8 (I: μA, C: μmol L−1), correlation coefficient 0.9997. The detection limit of 1.8 × 10−10 mol L−1 was achieved (S/N = 3). The applicability of the modified electrode was demonstrated by determination of serotonin in human serum. Moreover, the possible oxidation mechanism of 5-HT was discussed.