▎ 摘　　要

Biosensors are developed for monitoring signal molecules in a simple and rapid way, but their performance and stability are mainly limited by unstable biorecognition elements. Herein, we used a predesigned bioinorganic catalytic composite (nOPH10@GO) as a sensitive biological material to fabricate a high-performance organophosphorus hydrolase (OPH)-based biosensor. At first, the stability of OPH was enhanced through the in situ radical polymerization to generate an OPH nanocapsule (nOPH10), which was then assembled on graphene oxide (GO) to form a bioinorganic hybrid (nOPH10@GO). We confirmed the successful formation of a polymer shell on an enzyme surface and subsequently investigated its protective effects using the thermal treatment and organic solvent test. Compared to native OPH, nOPH10 exhibited enhanced enzymatic performance and stability, which could be also observed on the proposed electrode (nOPH10@GO/GCE). Specifically, nOPH10@GO/GCE can work steadily in the presence of different external stimuli and exhibited improved selectivity and stability. More importantly, owing to the enhanced catalytic activity of nOPH10@GO, the fabricated biosensor presented a wider linear range (0.2-60 mu M), a lower limit of detection (0.013 mu M), and higher repeatability and reproducibility in comparison with the naked enzyme electrode (OPH@GO/GCE). Our results highlighted the importance of the rational predesign of biorecognition materials in the development of a high-performance biosensing platform.