Oxidative Stripping of Starch-AgNPs for Nanomolar Indirect Electrochemical Sensing of BSA Using an L-Cysteine Modified Glassy Carbon Electrode

Abstract

Abstract In this study, an L-cystine-modified glassy carbon electrode (GCE) was developed as an electrochemical platform based on AgNP oxidative stripping for nanomolar indirect detection of bovine serum albumin (BSA) biomacromolecules. The Poly-L-Cys was formed by L-cysteine (L-Cys) monomers electro-polymerization on the GCE surface. L-Cys pending groups interacted with AgNPs through Ag-S chemical bonds while it interacted with BSA through van der Waals forces and hydrogen bonding. To characterize the bare GCE and GCE/L-Cys, cyclic voltammetry and electrochemical impedance spectroscopy were used. The oxidative stripping of AgNPs by the addition of BSA was monitored using linear sweep stripping analysis.