CoxFe3-xO4 hierarchical nanocubes as peroxidase mimetics and their applications in H2O2 and glucose detection

A facile approach was proposed for the synthesis of hierarchical CoxFe3-xO4 nanocubes (CF nanocubes), using Prussian Blue (PB) as precursor. The method consists of the synthesis of hierarchical cobalt-iron Prussian blue analogues (PBAs) through the reaction of PB nanocubes with CoCl2 in a water bath and subsequently calcining the corresponding PBA precursor. The obtained CF nanocubes were characterized using transmission electron microscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and N-2 adsorption-desorption isotherm measurements. It is found that the hierarchical CF nanocubes have a large specific surface area (108 m(2) g(-1)). Considering the hierarchical structure and the doping of Co in Fe3O4 are beneficial for the catalytic activity of the catalyst, an efficient and simple colorimetric biosensor for H2O2 and glucose was fabricated using CF nanocubes as a peroxidase mimetic. The good catalytic activity and low-cost make the hierarchical CF nanocubes a useful biocatalyst for a wide range of potential applications in medicine and biotechnology.