WS2 quantum dots as a sensitive fluorescence probe for the detection of glucose

In this paper, a new fluorescence method was developed for glucose detection by using tungsten disulfide quantum dots (WS₂ QDs) based on the transformation of Fe²⁺/Fe³⁺ and the enzymatic reaction. In the presence of Fe³⁺, the fluorescence for WS₂ QDs can be quenched via photoinduced electron transfer (PET), while Fe²⁺ does not influence the fluorescence of WS₂ QDs. Glucose can produce hydrogen peroxide (H₂O₂) in the presence of glucose oxidase (GOx). And Fe²⁺ can be transferred to Fe³⁺ via the oxidation of H₂O₂. So a sensitive and simple strategy for glucose detection can be developed due to the different influences of Fe²⁺ and Fe³⁺ on the fluorescence intensity of WS₂ QDs. Under the optimized experimental conditions, a linear response was obtained for glucose in the range of 1–60 μmol L⁻¹ with a detection limit 0.30 μmol L⁻¹. This method was further applied to the glucose detection in serum sample with satisfactory results.