Simple synthesis of ZnO nanoparticles on N-doped reduced graphene oxide for the electrocatalytic sensing of L-cysteine

A new kind of ZnO nanoparticle/N-doped reduced graphene oxide nanocomposite (ZnONPs/N-rGO) was synthesized through a low temperature, low-cost and one step hydrothermal process. By using the prepared nanocomposite as a modified electrode material, an L-cysteine electrochemical sensor was fabricated. X-ray diffraction, transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy and electrochemical techniques were used to study the nanocomposite. The nanocomposite shows a high electro-catalytic activity toward L-cysteine oxidation. Under the optimum determination conditions, the nanocomposite modified electrode provided L-cysteine with a broad detection range of 0.1–705.0 μM and a limit of detection of 0.1 μM (S/N = 3). This novel method was successfully used to determine L-cysteine in real samples.