Functionalization of pencil graphite electrode with nanostarch/chitosan for electrocatalytic detection of serotonin...

This study presents the development of a novel electrochemical sensor for the sensitive and selective detection of serotonin by a nanocomposite of chitosan and nanostarch. This environmentally friendly synthesized nanocomposite was characterized by using various techniques, including SEM, EDX, FTIR, XRD, UV-Vis spectroscopy, CV, and EIS. The sensor was fabricated by modifying a pencil graphite electrode with the synthesized nanocomposite. Electrochemical measurements of the electrode were performed using differential pulse voltammetry and square wave voltammetry. The sensor demonstrated excellent analytical performance, with a wide linear range, low limit of detection, high sensitivity, and selectivity for serotonin. The developed sensor showed detection limits of 1.41 ng/mL and 1.81 ng/mL, and quantification limits of 4.71 ng/mL and 6.04 ng/mL, with SWV and DPV, respectively. The practical applicability of the sensor was successfully demonstrated for the serotonin level in biological fluid samples. The proposed sensor offers a rapid, cost-effective, and sensitive approach for serotonin quantification, with potential for future applications in the simultaneous detection of multiple neurotransmitters.