Continuous phase regulation of MoSe₂ from 2H to 1T for the optimization of peroxidase-like catalysis

Nanozymes are a new generation of artificial enzymes that address the limitations of natural enzymes, with numerous reports on the development of high performance nanozymes for various applications. Herein, the phase regulation of network-like MoSe2 from the metal 1T phase to semiconductor 2H phase was achieved under different reaction conditions by a facile but efficient microwave-assisted solvothermal method. The coexisting 1T/2H-MoSe2 with edge enriched and defective nanostructures showed great enhancement of the peroxidase-like properties. This high enzymatic activity may arise from optimized active sites of 1T/2H-MoSe2, effectively leading to a rapid charge transfer within the substrate. In addition, chitosan functionalization not only greatly improves the dispersion stability of MoSe2, but also significantly increases its peroxidase-like activity, probably due to its enhanced affinity to hydrogen peroxide (H2O2). Based on these results we have established a highly sensitive colorimetric assay for the detection of H2O2 and glucose in human serum.