Enhancing the peroxidase-like activity of MoS₂-based nanozymes by introducing attapulgite for antibacterial application and sensitive detection of glutathione

Nanozymes are next-generation of nanomaterials with enzyme-like activities. In particular, nanozymes with peroxidase (POD)-like activity have been utilized in various fields, including antibacterial, detection, degradation, etc. However, their extensive applications were limited by their low catalytic activity currently. Herein, we have presented a composite nanozyme based on attapulgite (ATP) (Fe-ATP-MoS₂ (FAM)), which exhibited enhanced POD-like activity (185.33 U·mg⁻¹), 4.25 times higher than that of Fe-MoS₂ (FM) (43.63 U·mg⁻¹). The density functional theory (DFT) calculations indicated that the addition of ATP increased the electron density of metal centers (Mo and Fe). More importantly, Michaelis–Menten kinetics revealed that the introduction of ATP significantly enhanced the binding affinities of substrates through the pores of ATP, forming a highly concentrated substrate microenvironment and thus promoting its POD-like activity. Additionally, from molecular size and kinetic analysis, we proposed that the changes in substrate size before and after oxidation also significantly affected its Michaelis-constant (K_m) value. Furthermore, we utilized FAM in the applications of highly effective antibacterial application and sensitive detection of glutathione (GSH). In conclusion, this work provides a novel approach for designing a highly efficient nanozyme based on natural mineral composites.