PtCo bimetallic nanoparticles with high oxidase-like catalytic activity and their applications for magnetic-enhanced colorimetric biosensing.

A novel magnetic-enhanced colorimetric assay was constructed based on aptamer conjugated PtCo bimetallic nanoparticles (NPs) with high oxidase-like catalytic activity, high water solubility, low cell toxicity, and superparamagnetic properties. It was found that the incorporation of magnetic metal Co atoms into NPs could not only be facilitated for magnetic separation, but also resulted in the significantly improved oxidase-like catalytic activity of the nanoparticles for cancer-cell detection without the destructive H2O2. The present work demonstrates a general strategy for the design of multifunctional materials based on bimetallic nanoparticles for different applications, such as biosensors, nanocatalysts and nanomedicine.