Label-free detection of glucose based on quantum dots

A simple nanobiosensor based on CdTe/CdS quantum dots (QDs) was designed for the direct determination of glucose with high sensitivity. Herein we demonstrated that the photoluminescence (PL) of CdTe/CdS QDs was sensitive to hydrogen peroxide (H₂O₂). With glucose as substrate and glucose oxidase (GOx) as catalyzer, the product, H₂O₂ could quench the fluorescence of QDs. Experimental results showed that the decrease of fluorescent intensity was proportional to the concentration of glucose within the range of 1.8 ¿M-1 mM under the optimized experimental conditions. In addition, the detection was completed in 96-well plate as an original model of blood sugar detector. A good linear relationship was found within the range of 2 mM-30 mM. This QDs based sensor for glucose has the potential to be a portable blood sugar detector due to its high sample throughput, short assay time, low sample consumption and reduced overall cost.