Co 2 V 2 O 7 Particles with Intrinsic Multienzyme Mimetic Activities as an Effective Bioplatform for Ultrasensitive Fluorometric and Colorimetric Biosensing.

Nanozymes with various activities have attracted much attention owing to their great potential in the fields of biochemical analysis and environmental monitoring. Herein, for the first time, granular Co 2 V 2 O 7 particles were synthesized using a simple hydrothermal method with pH regulation, and the triple-enzyme (oxidase-like, peroxidase-like, and catalase-like) activities and catalytic mechanisms of the prepared particles were systematically studied. On the basis of the excellent oxidase-like and peroxidase-like activities of Co 2 V 2 O 7 particles, respectively, a colorimetric biosensor for detecting glutathione in health products (linear range: 2.5-20 μM) and a fluorescent platform for detecting glucose in human serum (linear range: 0.1-80 μM) were established, both of which had good selectivity and reliability. In particular, the fluorescence detection system exhibited ultrahigh sensitivity for H 2 O 2 , with a linear range of 0.008-3.2 μM, and a detection limit (0.002 μM) far superior to most reported in the literature to date. Furthermore, a one-step strategy for glucose detection was established to replace the traditional complicated two-step detection method, resulting in a more convenient detection process. These findings indicate the significant application prospects of Co 2 V 2 O 7 particles in the field of biocatalysis and provide useful information for the future development of cobalt vanadate nanomaterials as enzyme mimics.