茶叶中的茶多酚荧光检测方法

A method for the fluorescence detection of tea polyphenols

以石墨烯量子点为荧光探针,基于二氧化锰纳米片与石墨烯量子点之间发生有效的荧光共振能量转移,构建了一种茶叶中茶多酚含量的荧光检测新方法。MnO2纳米片使石墨烯量子点的荧光淬灭,而茶多酚能与MnO2发生氧化还原反应,将其还原成Mn^2+,使体系荧光恢复。茶多酚含量与荧光强度增量在20~750μg/mL范围内成线性相关,线性方程为F=1.0574c-114.9,线性相关系数为R=0.9936。将该方法用于茶叶中茶多酚含量的检测,结果与国标法接近。方法有望应用于食品中其它抗氧化物质的实时检测。

By using graphene quantum dots as fluorescent probes,a novel fluorescence method for detecting the tea polyphenols was developed based on the effective fluorescence resonance energy transfer(FRET)between manganese dioxide nanosheets and graphene quantum dots.Manganese dioxide nanosheets can quench the fluorescence of graphene quantum dots,while tea polyphenols can reduce manganese dioxide to Mn^2+ and restore the fluorescence of the system.The content of tea polyphenols was linearly correlated with the increase of fluorescence intensity in the range of 20-750μg/mL.The linear correlation equation was F=1.0574c-114.9,and the linear correlation coefficient was R=0.9936.The method was applied to the determination of tea polyphenols in tea,and the result was close to that of the national standard method.This method exhibited a lower detection limit and a wider detection range than the national standard method.It also has wide applicability and high accuracy,so it's expected to be applied to the real-time detection of other antioxidant substances in food.