Tungsten disulfide nanosheets-based colorimetric assay for glucose sensing.

We have developed a glucose oxidase (GOx)-mediated strategy for glucose detection, which is based on the intrinsic peroxidase-like activity of WS2 as a catalyst for the 3,3',5,5'-tetramethylbenzidine‑hydrogen peroxide (TMB-H2O2) reaction. The colorimetric assay involves two parts: generation of H2O2 from the oxidation of glucose catalyzed by GOx, and WS2 nanosheets that catalyze the reaction between TMB and H2O2. In this colorimetric assay, the enhancement of colorimetric signals depends directly on the increased H2O2 concentration, which, in turn, relies on the glucose concentration. The results show that the concentrations of the glucose were directly proportional to absorbance of the TMB solutions over a range of 1 nM-500 μM with a limit of detection of 0.1445 nM. In addition, this new colorimetric assay has been utilized for glucose detection in human serum with a satisfactory result.