Few-layered MoSe2 nanosheets as an efficient peroxidase nanozyme for highly sensitive colorimetric detection of H2O2 and xanthine

Molybdenum-containing and selenium-containing enzymes are generally prevalent in the biosphere, and the active sites of these involve molybdenum and selenium respectively. Herein, we for the first time demonstrated that few-layered molybdenum selenide (MoSe2) nanosheets possess intrinsic peroxidase-like activity. The few-layered MoSe2 nanosheets were prepared by a simple liquid exfoliation method. The catalytic process of the MoSe2 nanosheets accords with the Michaelis-Menten behavior and they have a higher affinity to both TMB and H2O2 compared to HRP. In addition, we established that the MoSe2 nanosheets catalyze the oxidation of TMB by promoting the electron transfer process from TMB to H2O2. More importantly, we applied the MoSe2 nanosheets to the field of biological detection by developing a highly sensitive and selective colorimetric detection of H2O2 and xanthine concentration. With these advantages, the few-layered MoSe2 nanosheets have critical potential in the diagnostics and biomedical fields.