Synthesis of RGO/Cu8S5/PPy Composite Nanosheets with Enhanced Peroxidase-Like Activity for Sensitive Colorimetric Detection of H2O2 and Phenol

In this paper, a novel strategy for the fabrication of reduced graphene oxide (rGO)/Cu8S5/polypyrrole (PPy) composite nanosheets with Cu8S5 nanoparticles and PPy layer anchored on the surface of rGO as peroxidase-like nanocatalyst is reported. During the synthesis, graphene oxide (GO)/CuO composite nanosheets are prepared first and used as templates, then the sulfuration of CuO and polymerization of pyrrole are accompanied with the reduction of GO, resulting in ternary rGO/Cu8S5/PPy composite nanosheets. The synthesized Cu8S5 nanoparticles with a diameter in the range from tens to hundreds of nanometers are dispersed within PPy decorated rGO nanosheets. The resultant ternary rGO/Cu8S5/PPy composite nanosheets exhibit a higher peroxidase-like catalytic activity toward the oxidation of 3,3', 5,5'-tetramethylbenzidine in the presence of H2O2 than GO/CuO and rGO/CuS composite nanosheets, revealing a synergistic effect on their activity. The as-prepared rGO/Cu8S5/PPy platform provides a simple colorimetric approach for the detection of H2O2 and phenol with a high sensitivity. This work offers a new way for the fabrication of rGO-based nanocomposite with superior enzyme-like activity, which displays great potential applications in biocatalysis and environmental monitoring.