Gradient orbital coupling to boost radical adsorption on Cu atom sites for efficient biocatalytic performance

Molybdenum disulfide (MoS₂) holds broad application prospects in the biomedical field, yet its inherent enzyme-mimetic activity exhibits limitations. This study reveals that Cu doping unleashes exceptional biocatalytic activity of MoS₂ by forming d-p-d gradient orbital coupling. Projected density of states analysis indicates this coupling establishes covalent Cu-S-Mo bonds, precisely regulating radical adsorption on Cu atom sites to achieve highly efficient scavenging rate. The resulting Cu-MoS₂ exhibits superoxide dismutase-like activity approximately 40-fold higher than pure MoS₂, along with excellent catalase (CAT)-like performance. Furthermore, it demonstrates broad-spectrum reactive species scavenging capability, especially toward •OH, O₂^·- and ONOO^- radicals, achieving 97.9% elimination of ABTS^•+ at a concentration as low as 168 nM, which confirms its potent antioxidant properties. Crucially, this material demonstrates significant therapeutic efficacy in a mouse model of acute kidney injury. This work extends orbital coupling engineering strategies, offering novel insights for advancing nanocatalyst design to address complex biomedical challenges.