Two-dimensional hybrid mesoporous Fe2O3–graphene nanostructures: A highly active and reusable peroxidase mimetic toward rapid, highly sensitive optical detection of glucose

•Two-dimensional mFe2O3–G was developed as a peroxidase mimetic for the first time.•mFe2O3–G exhibits high catalytic activities toward TMB oxidation by H2O2.•mFe2O3–G was used for rapid, highly sensitive and selective optical glucose detection.

In this article, for the first time, two-dimensional hybrid mesoporous Fe2O3–graphene (mFe2O3–G) nanostructures were developed as a peroxidase mimetic with catalytic activities superior to those of mFe2O3, G, and previously reported Fe-based peroxidase mimetics. The high-surface-area mFe2O3 not only offers a large number of catalytically active sites, but also facilitates the diffusion of 3,3,5,5-tetramethylbenzidine (TMB) and H2O2 toward G surface. On the other hand, G is π-rich and thus favors the adsorption and enrichment of TMB within these pores. These synergistic effects lead to highly improved catalytic performances. Based on these findings, a simple, rapid, and highly sensitive and selective optical detector of glucose has been developed and demonstrated in buffer solution with a pretty low detection limit of 0.5 μM. In addition, this nanosensor is reusable and can also be used for glucose detection in diluted serum.