Highly sensitive and rapid colorimetric sensing platform based on water-soluble WO x quantum dots with intrinsic peroxidase-like activity.

This report outlines a rapid and highly sensitive colorimetric sensing platform based on a novel water-soluble WOx quantum dots (QDs) as enzymatic mimics. The WOx QDs, synthesized by a green hydrothermal method, were proven to possess excellent intrinsic peroxidase-like activity. The peroxidase substrate, 2, 2'-azinobis (3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS) could be catalyzed oxidation by WOx QDs quickly in the present of H2 O2 to form a green color. Due to its excellent properties such as excellent water-solublity, good biocompatibility, easy preparation, and high stability, the proposed system showed typical Michaelis-Menten kinetics and high affinity for ABTS and H2 O2 , indicating WOx QDs can be used as satisfactory peroxidase mimics. Together with the fast detection process, WOx QDs-based colorimetric sensing system provided a facile, sensitive, and accurate method for the determination of H2 O2 and glucose. The real glucose samples in human serum samples were detected with satisfying results. The proposed sensing platform not only expands the applications of WOx and WOx QDs-based nanocomposites, but also provides an alternative technique for biological, biomedical and environmental sample assay.