One-Step Synthesis of Rox-DNA Functionalized CdZnTeS Quantum Dots for the Visual Detection of Hydrogen Peroxide and Blood Glucose

As the blood glucose concentration is an important clinical parameter of diabetes, the rapid and effective detection of blood glucose is very significant for monitoring and managing diabetes. Here, a facile method to prepare Rox-DNA functionalized CdZnTeS quantum dots (QDs) was developed. The Rox-DNA functionalized CdZnTeS QDs were prepared by a one-pot hydrothermal method through phosphorothioate DNA bound to QDs, which were employed as a ratiometric fluorescent probe for the rapid and sensitive detection of H₂O₂ and glucose. Compared with the traditional multistep construction of ratiometric fluorescent probes, this presented approach is simpler and more effective without chemical modification and complicated separation. The CdZnTeS QDs with green fluorescence is specifically sensitive to H₂O₂, while the red fluorescence of Rox is invariable. H₂O₂ is the product from the oxidation of glucose catalyzed by glucose oxidase (GOx). Therefore, a facile method to detect H₂O₂ and glucose with a detection limit of 0.075 μM for H₂O₂ and 0.042 μM for glucose was developed. In addition, this proposed probe has been employed for the detection of glucose in human serum with a satisfactory result. Moreover, this probe has been used for visual detection, and the health and diabetics can be distinguished by the naked eye. Meanwhile, this nanoprobe is also generalizable and can be extended to the detection of many other H₂O₂-mediated analytes