CoSe2 nanoflakes: An artificial nanoenzyme with excellent peroxidase like activity

Herein, we report an artificial nanoenzyme: CoSe2 with unique flake like morphology, exhibiting an excellent intrinsic peroxidase like activity. In comparison with naturally found Horseradish peroxidase (HRP), silver and gold based biomimetics, these nanoflakes mimics enhanced peroxidase like activity with higher Kcat and Vmax values for oxidation of both 3,3,5,5-tetramethylbenzidine (Kcat = 42.8 s−1, Vmax = 0.5139 μM/s) and o-phenylenediamine (Kcat = 84.95 s−1, Vmax = 1.0139 μM/s) under optimized pH conditions. A single electron transfer mechanism from TMB/OPD substrate favors formation of blue color TMB+/OX-OPD products. The unique flakes like morphology of CoSe2 nanoflakes provides active channels which offers better accessibility for the reactant, resulting in enhanced catalytic efficiency of CoSe2 nanoflakes. Additionally, there is no significant loss in the catalytic efficiency of CoSe2 nanoflakes even after 365 days which endorses higher thermal and chemical stability of these synthesized CoSe2 nanoflakes.