Enhanced Peroxidase-Like Activity of MoS? Quantum Dots Functionalized g-C?N? Nanosheets towards Colorimetric Detection of H?O?.

ABSTRACT: MoS? quantum dots (QDs) functionalized g-C?N? nanosheets (MoS?@CNNS) were prepared through a protonation-assisted ion exchange method, which were developed as a highly efficient biomimetic catalyst. Structural analysis revealed that uniformly-dispersed MoS? QDs with controllable size and different loading amount grew in-situ on the surface of CNNS, forming close-contact MoS?@CNNS nanostructures and exhibiting distinct surface properties. Compared to MoS? QDs and CNNS, the MoS?@CNNS nanocomposites exhibited a more than four times stronger peroxidase-like catalytic activity, which could catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H?O? to generate a blue oxide. Among the MoS?@CNNS nanocomposites, MoS?@CNNS(30) was verified to present the best intrinsic peroxidase-like performance, which could be attributed to the more negative potential and larger specific surface area. A simple, rapid and ultrasensitive system for colorimetric detection of H?O? was thus successfully established based on MoS?@CNNS, displaying nice selectivity, reusability, and stability. The detection limit of H?O? could reach as low as 0.02 ?M. Furthermore, the kinetic and active species trapping experiments indicated the peroxidase-like catalytic mechanism of MoS?@CNNS. This work develops a novel, rapid, and ultrasensitive approach for visual assay of H?O?, which has a potential application prospect on clinical diagnosis and biomedical analysis.

SUBMITTER: Ju P 

PROVIDER: S-EPMC6316126 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature