Fabrication of a novel impedimetric sensor based on l-Cysteine/Cu(II) modified gold electrode for sensitive determination of ampyra

Abstract

This paper presents a novel impedimetric sensor for the sensitive determination of ampyra (Am) based on the l-Cysteine/Cu (II) modified gold electrode (Cu (II)/L-Cys/AuE). This novel sensing layer was characterized by different techniques, including atomic force microscopy (AFM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Am determination by conventional electrochemical methods is not possible, because of its high redox overpotential. Therefore, [Fe(CN)6]3-/4- was used as a redox probe for the impedimetric determination of Am. Under the optimized conditions, the calibration curve for Am concentration was linear in the range 0.010–40.0 nM with a detection limit of 0.0028 nM. The practical applicability of the proposed sensor was examined by evaluating the detection of Am in biological fluids and pharmaceutical samples with satisfied recoveries. Therefore, the prepared sensor can hold great promise for fast, simple and sensitive detection of Am in various real samples.