Voltammetric Detection of Captopril on Graphite Screen Printed Electrodes

Abstract

Abstract We report the electrochemical detection of captopril on commercially available screen printed electrodes (GSPE); it exploits the silver residue left behind on a GSPE during its manufacturing process and involves the catalytic formation of the silver thiol complex (Ag + +RSH→AgSR+H + ) at potentials corresponding to the oxidation of silver. The oxidation of the silver thiol complex was found to vary linearly with the captopril concentration up to 0.8 mM. A sensitivity of 13.34±0.58 μA mM −1 is reported with a limit of detection of 4.27±0.18 μM.