Single-Atom Modulated Biocatalytic Selectivity on WSe2 Clusters

Two-dimensional WSe2 has garnered significant interest owing to its special electronic properties and high catalytic activity. However, the substrate catalytic selectivity of WSe2 has still been poorly studied. In this study, ultrasmall M-WSe2 clusters (M = Cu, Ru, Zn) were designed by a single-atom doping strategy and catalytic selectivity. The Cu-WSe2 and Zn-WSe2 clusters show high antioxidant activity, both about a 7.2-fold enhancement higher than the WSe2 clusters. Meanwhile, Ru-WSe2 and Cu-WSe2 prefer to exhibit catalase-like (CAT-like) activities, about 5.6- and 2.5-fold enhancement after single-atom doping. Ru-WSe2 displays significant peroxidase-like (POD-like) activity with a better affinity than natural HRP, showing a Km value of 0.43 mM. In contrast, pure WSe2 clusters exhibit NADH oxidase-like (NOX-like) activity that catalyzes the regeneration of NAD+. Density functional theory calculations reveal that catalytic selectivity originates from differential electron transfer around different single atoms as well as d-band center modulation. In vitro cell experiments demonstrated that the M-WSe2 clusters can modulate the oxidation–reduction balance through single-atom engineering.