Nanocomposite incorporating V2O5 nanowires and gold nanoparticles for mimicking an enzyme cascade reaction and its application in the detection of biomolecules.

Artificial enzyme mimics are a current research interest, and many nanomaterials have been found to display enzyme-mimicking activity. However, to the best of our knowledge, there have not hitherto been any reports on the use of pure nanomaterials to construct a system capable of mimicking an enzyme cascade reaction. Herein, we describe the construction of a novel nanocomposite consisting of V2O5 nanowires and gold nanoparticles (AuNPs) through a simple and facile chemical method, in which V2O5 and AuNPs possess intrinsic peroxidase and glucose oxidase (GOx)-like activity, respectively. Results suggest that this material can mimic the enzyme cascade reaction of horseradish peroxidase (HRP) and GOx. Based on this mechanism, a direct and selective colorimetric method for the detection of glucose has been successfully designed. Because single-strand and double-strand DNA (ssDNA and dsDNA) have different deactivating effects on the GOx-like activity of AuNPs, the sensing of target complementary DNA can also be realized and disease-associated single-nucleotide polymorphism of DNA can be easily distinguished. Our study opens a new avenue for the use of nanomaterials in enzyme mimetics, and holds promise for the further exploration of nanomaterials in creating alternative catalytic systems to natural enzymes.