Detection of hydroquinone with a novel fluorescence probe based on the enzymatic reaction of graphite phase carbon nitride quantum dots

This paper developed a sensitive method for detecting hydroquinone by combining the unique optical properties of quantum dots and the specificity of enzymatic reactions. The interesting results shown that the fluorescence of graphite phase carbon nitride quantum dot (g-CNQDs) was quenched directly by benzoquinone or indirectly by hydroquinone (H2Q), and the possible quenching mechanism was proposed. Quinone might generate by catalyzing the oxidation of H2Q with horseradish peroxidase (HRP) in the presence of hydrogen peroxide. The intermediate quinone could effectively quench the fluorescence of g-CNQDs quantum dots. Therefore, a novel fluorescence probe based on g-CNQDs Quantum Dots was successfully used to detect H2Q by strongly quenching the fluorescence of g-CNQDs Quantum Dots which mediated by horseradish peroxidase enzymes. The detection limit was as low as 0.04 μM (S/N = 3), and the linear range was 0.5-11.6 μM. This kind of quantum dot-enzyme system has the advantages of simple operation, no modification of quantum dots, low cost, high sensitivity and short detection time.