2D CTAB-MoSe(2) Nanosheets and 0D MoSe(2) Quantum Dots: Facile Top-Down Preparations and Their Peroxidase-Like Catalytic Activity for Colorimetric Detection of Hydrogen Peroxide

We report the facile and economic preparation of two-dimensional (2D) and 0D MoSe(2) nanostructures based on systematic and non-toxic top-down strategies. We demonstrate the intrinsic peroxidase-like activity of these MoSe(2) nanostructures. The catalytic processes begin with facilitated decomposition of H(2)O(2) by using MoSe(2) nanostructures as peroxidase mimetics. In turn, a large amount of generated radicals oxidizes 3,3,5,5-tetramethylbenzidine (TMB) to produce a visible color reaction. The enzymatic kinetics of our MoSe(2) nanostructures complies with typical Michaelis–Menten theory. Catalytic kinetics study reveals a ping–pong mechanism. Moreover, the primary radical responsible for the oxidation of TMB was identified to be Ȯ(2)(−) by active species-trapping experiments. Based on the peroxidase mimicking property, we developed a new colorimetric method for H(2)O(2) detection by using 2D and 0D MoSe(2) nanostructures. It is shown that the colorimetric sensing capability of our MoSe(2) catalysts is comparable to other 2D materials-based colorimetric platforms. For instance, the linear range of H(2)O(2) detection is between 10 and 250 μM by using 2D functionalized MoSe(2) nanosheets as an artificial enzyme. Our work develops a systematic approach to use 2D materials to construct novel enzyme-free mimetic for a visual assay of H(2)O(2), which has promising prospects in medical diagnosis and food security monitoring.