2D g-C3N4–MnO2 nanocomposite for sensitive and rapid turn-on fluorescence detection of H2O2 and glucose

Abstract

The accurate determination and quantification of H₂O₂ and glucose are necessary for diagnosis and bioengineering. Herein, we have reported a novel method for the rapid and selective detection of H₂O₂ and glucose using g-C₃N₄–MnO₂ nanocomposite. In this method, the fluorescence of graphitic-C₃N₄ (g-C₃N₄) was quenched by MnO₂, which was attributed to fluorescence resonance energy transfer (FRET) between g-C₃N₄ nanosheets and the deposited MnO₂. When H₂O₂ was introduced, the MnO₂ was reduced to Mn²⁺, which led to the elimination of FRET and the recovery of the quenched fluorescence. This H₂O₂ detection system was also suitable for glucose detection since H₂O₂ is one of the main products in the oxidation reaction of glucose catalyzed by glucose oxidase. Therefore, our method has a great application prospect in diabetes research and clinical diagnosis. Additionally, the fluorescence was linear with the concentration of H₂O₂ in the range of 0 to 130 μM, with the detection limit of 1.5 μM, and also showed a good linear relationship with glucose in the range of 0 to 150 μM, with the detection limit of 1.5 μM. In addition to a wide linear response, the proposed sensor showed advantageous characteristics, such as easy preparation, low cost, high selectivity, rapid detection, and turn-on fluorescence response. Therefore, our proposed strategy would provide a new general strategy to develop low-cost, sensitive biological and clinical diagnostic methods.