Fluorescent glucose sensing using CdTe/CdS quantum dots–glucose oxidase complex

Abstract

A novel fluorescent glucose probe, CdTe/CdS quantum dots (QDs)–glucose oxidase (GOx) complex, was synthesized by the chemical conjugation of aqueous CdTe/CdS QDs and GOx. The concentration of glucose is related to the quenching of the fluorescent CdTe/CdS QDs, which is caused by the production of hydrogen peroxide under the catalysis of GOx. Fluorescence spectrophotometry, UV-vis absorption spectroscopy and transmission electron microscopy were used to characterize the CdTe/CdS QDs–GOx complex. The optimum catalytic pH and temperature of the CdTe/CdS QDs–GOx complex were determined to be 7 and 40 °C, respectively. A relation between the fluorescence intensity of the CdTe/CdS QDs–GOx complex and the glucose concentrations was found based on a modified Stern–Volmer equation.