Formation of PtCuCo Trimetallic Nanostructures with Enhanced Catalytic and Enzyme-like Activities for Biodetection

The unique enzyme-like properties of metal nanoparticles (NPs) hold great promise for chemical and biomedical applications; implementation relies on improvements in their catalytic efficiency. We have constructed PtCuCo nanostructures using hydrothermal treatment of Co3O4, Cu2+, and Pt2+ in aqueous solutions, resulting in PtCuCo trimetallic alloy NPs having hollow structures, as confirmed by TEM, XRD, XPS, and EDS analyses. These PtCuCo NPs are capable of oxidizing 3,3′,5,5′-tetramethylbenzidine (TMB) in either the absence or presence of hydrogen peroxide, suggesting efficient peroxidase- and oxidase-like activity. These NPs could also catalyze the reduction of 4-nitrophenol by NaBH4. We believe that the combination of Pt and oxidized Cu and Co species results in surfaces with rich active sites possessing a wide range of electronic variation, which promotes both generation of hydroxyl radicals and electron transfer. Consequently, the catalytic capabilities of our PtCuCo NPs are greater than those of either Pt or PtCu NPs. Building upon the peroxidase-like activity of PtCuCo NPs, we developed a colorimetric method not only capable of specifically detecting glucose, but also able to detect rongalite and HS–, on the basis of the inhibitory effect of these substances upon PtCuCo nanoperoxidase.