Nanoarchitectured superparamagnetic iron oxide-doped mesoporous carbon nanozymes for glucose sensing

The incorporation of nanoarchitectonics into the development of nanozymes to achieve target-specific geometry, dense active sites, and cascade catalysis is highly demanded for developing ultrasensitive bioassays. The improved dispersion and uniform distribution of metal active sites onto a three-dimensional (3D) mesoporous carbon support (MC) with a high surface area can lead to enhanced substrate binding, mobility, and collision probability and therefore, increased peroxidase mimetic activity. Herein, we report the fabrication of well-dispersed superparamagnetic iron oxide (IO) nanoparticles (NPs) on mesoporous carbon (IO-MC) support with high Fe3+ active sites, high surface area, and ordered mesoporous pore channels that show promising catalytic activity at room temperature. The as-prepared IO-MC shows good nanozyme activity at room temperature with highly favorable Michaelis-Menten constant, Km (0.242 mM) and fast reaction rate (0.193 × 10−7 MS−1). Finally, we demonstrate the functionality and pre-eminence of IO-MC nanozyme for bioassay. As a proof-of-concept, we develop a superior glucose assay that provides a LOD (limit of detection) of 2 µM in the spiked sample. These findings suggest that homogeneously dispersed iron oxide NPs on MC show promising potential as next-generation nanozyme for developing sensitive bioassays.