Poly (L-Cysteine) Modified Glassy Carbon Electrode as a Voltammetric Sensor for the Individual and Simultaneous Determination of Serotonin and Tyramine

Abstract

This work reports a voltammetric sensor for the individual and simultaneous determination of two important biogenic amines serotonin (ST) and tyramine (TYM) based on L-cysteine grafted glassy carbon electrode (p(L-cys)/GCE). Square wave voltammetric results reveal that the overpotential for the electro oxidation of these compounds were decreased and the peak current increased significantly at the modified electrode compared to bare GCE. The sensor displayed well defined peaks with sufficient peak separation for the simultaneous determination of these compounds when phosphate buffer of pH 7 was used as the supporting medium. All the sensor parameters were optimized and under these conditions, determinations have been achieved in wide linear ranges with nanomolar detection limits both individually and simultaneously. The proposed sensor has been used for practical application in synthetic blood serum samples.