Hierarchical porous MoS2 particles: excellent multi-enzyme-like activities, mechanism and its sensitive phenol sensing based on inhibition of sulfite oxidase mimics

Abstract

It is important to exploit highly efficient methods for detecting pollutants selectively and sensitively. Artificial enzymes are promising to replace natural enzymes with diverse functions for sustainable developments and various applications. However, it remains the challenge to develop novel mimic enzymes or multi-enzyme mimics for pollutant detection. Herein we report hierarchical porous MoS₂ particles prepared by a simple hydrothermal method, which demonstrated excellent sulfite oxidase (SuO_x)-, nicotinamide adenine dinucleotide (NADH) oxidase- and superoxide dismutase-mimicking activities. In addition, the catalytic conditions for SuO_x-like and NADH oxidase-like activities of MoS₂ were optimized. The catalytic mechanism of the NADH oxidase mimics is that O₂ involves in the oxidation of NADH, to generate O₂^.- intermediate and finally turn to H₂O₂, while SuO_x mimics comes from that MoS₂ particles can effectively catalyze sulfite to reduce [Fe(CN)₆]^3-. Based on the excellent SuO_x-like activity of MoS₂ particles, while phenol can inhibit the oxidation of sulfite, a phenol colorimetric sensor was explored with the dynamic range of 2-1000 μM and the limit of detection of 0.72 μM, applicable to detect phenol in effluents. Therefore, MoS₂ particles with the SuO_x-like, NADH oxidase-like and SOD-like activities has broad application prospects in environmental monitoring and bio-analysis.

Keywords: Colorimetric phenol sensor; MoS(2) particles; Multi-enzyme mimics; NADH-like activity; SuO(x)-like activity.