基于碳点的“开-关-开”型荧光探针测定蔬菜中的谷胱甘肽

“On-off-on”fluorescent probe based on carbon dots for the detection of glutathione in vegetables

以邻苯二胺、柠檬酸、乙醇为前体物质,采用自下而上的一步水热法,制备了一种蓝色荧光碳点(BCDs),以此构建荧光探针,用于检测蔬菜中的谷胱甘肽(GSH)。结果表明,在碳点(CDs)中加入Cu^(2+)后可使BCDs荧光猝灭;在该猝灭体系中加入GSH后会使BCDs-Cu^(2+)体系的荧光恢复。由此建立了一种“开-关-开”型检测GSH的新方法。在激发波长390 nm下,BCDs发射峰位于445 nm处,可以实现对GSH的检测,方法线性范围是0~80μmol/L,检出限(LOD)为0.0368μmol/L。该方法用于实际样品蔬菜中GSH的测定,回收率为89.6%~104.3%,相对标准偏差(RSDs)为1.2%~5.2%。

In this work,o-phenylenediamine,citric acid and ethanol were used as precursors to prepare blue-emissive fluorescent carbon dots(BCDs)through a bottom-up hydrothermal one-step method.Then,BCDs were employed as a fluorescent probe for rapid detection of Cu^(2+)and glutathione(CSH)in vegetables.The results showed that the fluorescence of BCDs could be quenched by copper ion,and the quenched fluorescence of BCDs-Cu^(2+)can be recovered by GSH.Based on this principle,an'on-off-on'method for detection of CSH was established.The emission peak of BCDs-Cu^(2+)located at 445 nm under excitation wavelength of 390 nm.The linear range of the method was 0-80μmol/L and limit of detection(LOD)was 0.0368μmol/L.The recoveries of GSH in the actual vegetable samples were 89.6%-104.3%,with the relative standard deviations(RSDs)of 1.2%-5.2%.