Hierarchical flower-like manganese oxide/polystyrene with enhanced oxidase-mimicking performance for sensitive colorimetric detection of glutathione

Glutathione (GSH) is an important antioxidant and free radical scavenger that converts harmful toxins into harmless substances and excretes them out of the body. In this paper, 3D hierarchical flower-like nanozyme named MnO2/PS (polystyrene) was successfully prepared by template method for the first time. After the systematical studies, MnO2/PS nanozyme was evaluated to possess favorable oxidase activity and direct 3,3',5,5'-tetramethylbenzidine (TMB) catalytic ability in the near-neutral environment at room temperature. With the addition of different concentrations of GSH, oxidized TMB can be reduced to TMB with the whole process from blue to nearly colorless be observed by naked eyes. In addition, there is a good linear relationship in the range 1-50 μM and a detection limit of 0.08 μM. The method proposed can be successfully applied to the detection of reduced GSH in tablets and injections with good selectivity and high sensitivity. The analysis results exhibited good consistency with the results obtained by HPLC.