Ru incorporation for boosting Co3O4 oxidase-like activity in dopamine colorimetric detection

Co3O4 has emerged as an important transition metal oxide in imitating nature enzyme, but it affords low oxidase mimetic activity. Herein, Ru doping has been utilized to modulate Co3O4 oxidase-like activity. Various Ru-doped Co3O4 nanoparticles (RuxCo3-xO4 NPs, x ≤ 0.3) were prepared and utilized as oxidase mimic to trigger 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation. The catalytic performance varies with Ru incorporation, and Ru0.3Co2.7O4 NPs shows the highest oxidase mimetic activity. In comparison with Co3O4 NPs, Ru0.3Co2.7O4 NPs displays 2.8-fold lower Km yet 14.3-fold higher catalytic efficiency. As a highly efficient oxidase mimic, Ru0.3Co2.7O4 NPs holds promising in setting up colorimetric sensing platform for biomolecule dopamine (DA) detection. This work provides guidance for regulating Co3O4 oxidase mimic via simple Ru doping, and establishes a facile colorimetric sensing method for DA.