▎ 摘　　要

Robust and efficient multimodal catalysis platforms that possess high catalytic activity and enhanced electrical conductivity are preferred for enhancing the electrical analysis performance under a low over potential. This report describes a function-switchable amperometric sensor for electrochemical monitoring hydrogen peroxide and glucose under relatively low overpotential based on PEI-functionalized metal-organic framework (P-MOF) supported gold nanoparticles/nitrogen-doped graphene quantum dots (AuNPs/N-GQDs) and glucose oxidase. AuNPs/N-GQDs with high peroxidase mimicking activity was anchored on the P-MOF modified electrode surface as H2O2 sensors, exhibiting a high sensitivity of 134.26 mu A mM(-1) cm(-2) and a detection limit of 3.38 mu M. Subsequently, AuNPs/N-GQDs-P-MOF used as a nanocarrier for glucose oxidase (GOx) to achieve "cascade nanoreactor " amplification for glucose detection. The amplified amperometric glucose biosensor showed excellent anti-interference ability, reproducibility, and a limit of detection as low as 0.7 mu M (S/N = 3) with high sensitivity of 1512.4 mu A mM(-1) cm(-2). In addition, the feasibility of the electrochemical biosensor for accurate and quantitative detection of glucose in human serum samples was confirmed with a recovery ranging from 93.2 to 99.3%. The strategy of combining AuNPs/N-GQDs-P-MOF and glucose oxidase for cascade catalysis in this work provides a simple yet efficient approach to prepare nanomaterial-based enzyme-mimics and enzymes hybrids with high performance, which holds great potential in biological and chemical applications of electrochemical devices and biosensing. (c) 2021 Elsevier Ltd. All rights reserved.