Metal–organic framework derived hollow polyhedron CuCo2O4 functionalized porous graphene for sensitive glucose sensing

Abstract

A hollow CuCo2O4 polyhedron/porous reduced graphene oxide (PrGO) composite was prepared by simple thermolysis-induced transformation of heterobimetallic zeolitic imidazolate frameworks/porous graphene oxide (Cu-Co-ZIFs/PGO). In this strategy, the PGO was suitable for Cu-Co-ZIFs growing and anchoring, and the framework acted as sacrificial template during the formation of morphology-inherited hollow polyhedrons. In the obtained composite, PrGO sheets not only provided conduction path, but also served as protective agent to prevent the aggregation of crystals. The hollow rhombic dodecahedral CuCo2O4 possessed plentiful active sites and high electrocatalytic activity. When the composite was optimized and used for glucose sensing, it displayed good performance with a wide linear range of 0.5–3354μM, a low detection limit of 0.15μM (S/N=3), a high sensitivity of 2426μAmM−1cm−2 and short response time (<3s). Moreover, it could resist the interference of coexistent substances from serum sample etc. Thus the composite modified glassy carbon electrode was a promising enzyme-free glucose sensor.