Single Layer of Gold Nanoparticles Self-Assembled on Gold Electrode as a Novel Sensor with High Electrocatalytic Activity

Abstract

Herein, gold nanoparticles (AuNPs) coated with cysteine (CySH) with exceptional physical and chemical properties have been utilized as a novel platform for gold electrode modification. The prepared Au/CySH/AuNPs exhibited the dispersion of high density AuNPs which were densely decorated on the surface of modified electrode. The morphology, structure and electrochemical performance of the sensor were characterized by scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperomety techniques. The results indicated that the modified electrode has a notable catalytic activity toward cysteine oxidation. Under optimized conditions the calibration plots were linear in the concentration range of 1.0–40 μM with a detection limit of 250 nM. The modified electrode indicated reproducible behavior and a high level stability during the experiments, making it particularly suitable for analytical purposes.