A l-cysteine sensor based on Pt nanoparticles/poly(o-aminophenol) film on glassy carbon electrode

Platinum nanoparticles (nano-Pt) and poly(o-aminophenol) (POAP) were fabricated onto the glassy carbon electrode(GCE) to form the nano-Pt/POAP/GCE for the electrochemical determination of l-cysteine. The POAP film was obtained through electrochemical polymerization of o-aminophenol on GCE. The nano-Pt was electrochemically deposited onto the surface of the activated POAP/GCE The resultant nano-Pt/POAP/GCE was characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), and showed excellent electrochemical response to l-cysteine at low oxidative potential in Britton–Robinson (BR) buffer solution (pH = 3.0), with good stability and sensitivity, and featured with a low detection limit (0.08 μM, signal/noise = 3) and wide linear range (0.4 μM–6.3 mM).The mechanism for the electrochemical oxidation of l-cysteine on the nano-Pt/POAP/GCE was also investigated.