An electrochemical sensor based on copper nanowires-PDDA modified glassy carbon electrode for amperometric detection of cysteine in alkaline medium

Abstract

The development of highly efficient and stable electrocatalysts for their application in electrochemical detection is desirable. Herein, a new copper nanowires (CuNWs) modified electrode was fabricated by coating poly(dimethyl diallyl ammonium chloride) (PDDA) stabilized CuNWs composite onto the the glassy carbon electrode (GCE), and used for electro-catalyze and determination of cysteine (CySH). The morphology, structure, and surface property of fabricated CuNWs were tested using SEM, XRD, and XPS, separately. Electrocatalytic behavior of the modified electrode (CuNWs-PDDA/GCE) for CySH oxidation in alkaline medium was researched by cyclic voltammetry (CV) and chronoamperometry (CA) thoroughly, displaying excellent electrocatalytic oxidation activity and sensing ability towards CySH with a rapid and sensitive anodic current response at low oxidation potential. In the amperometric detection of CySH, the as-prepared electrode displayed a significantly wide linear range from 2 μM to 260 μM and a detection limit of 0.19 μM with a sensitivity of 1.430 μAμM−1cm−2. The proposed CySH sensor exhibited good reproducibility, stability, and anti-interference ability, and has been used to detect CySH in human plasma samples successfully with good applicability.