PEGylated molybdenum dichalcogenide (PEG-MoS2) nanosheets with enhanced peroxidase-like activity for the colorimetric detection of H2O2

Abstract

To improve the peroxidase-like activity of molybdenum dichalcogenides (MoS₂), surface modification, such as combing with monometallic or bimetallic nanoparticles, is of great and widespread interest. However, only a few studies have been reported on the modification of MoS₂ with non-metallic materials. Herein, we report a study on the peroxidase-like activity of novel PEGylated MoS₂ (PEG-MoS₂) nanosheets prepared using a simple liquid-phase exfoliation and pegylation process. Compared to the undecorated MoS₂ nanosheets, PEG-MoS₂ nanosheets have improved water dispersiblity and stability, which are beneficial for improving the peroxidase-like activity, as well as the catalysis velocity and affinity for TMB or H₂O₂. Based on PEGylated MoS₂, we successfully established a new platform for the colorimetric detection of H₂O₂ with a limit of detection (LOD) of 1.18 μM, which is comparable to that of the majority of the reported enzyme mimics of inorganic graphene analogues. More importantly, the as-prepared PEG-MoS₂ nanosheets are environmentally friendly, water dispersible, low cytotoxic, and easily prepared, which indicate that PEG-MoS₂ is a type of promising enzyme mimics and extremely likely to be applied in cell-based assay systems without any adverse reactions.