title: Switch-on fluorescence sensing of glutathione in food samples based on a graphitic carbon nitride quantum dot (g-CNQD)-Hg²⁺ chemosensor.
abstract: Fluorescence sensing of specific biological molecules by artificial chemosensors is a versatile technique. In the present work, a switch-on fluorescence sensor for rapid, sensitive, and selective sensing of glutathione (GSH) in food samples was developed. This method was based on the g-CNQDs-Hg(2+) system, in which the initial fluorescence from g-CNQDs was quenched by Hg(2+) with an electron transfer process. In the presence of GSH, the fluorescence sensor was switched to the "on" state, which was attributed to a competitive affinity of Hg(2+) to GSH and the functional groups on the surface of g-CNQDs. Under the optimal conditions, the limit of detection (LOD) of 37 nM for GSH was achieved with a wide range of 0.16-16 μM. The repeatability was better than 5.3% for GSH in both standard and food samples (n = 3). Finally, this fluorescence sensor was successfully employed for the determination of GSH in various kinds of food samples with excellent recoveries. Furthermore, this application may pave a new way for fluorescence sensing of other substances in food samples.
authors: State Key Laboratory of Applied Organic Chemistry and ‡Department of Chemistry, Lanzhou University , Lanzhou 730000, China.
authors: Yali
authors: Y
authors: Xu
authors: Xiaoying
authors: X
authors: Niu
authors: Haijuan
authors: H
authors: Zhang
authors: Laifang
authors: L
authors: Xu
authors: Shengguo
authors: S
authors: Zhao
authors: Hongli
authors: H
authors: Chen
authors: Xingguo
authors: X
authors: Chen
mesh_terms: D005453:Fluorescence; D005504:Food Analysis / Q000295:instrumentation* / Q000379:methods; D005978:Glutathione / Q000032:analysis*; D006108:Graphite; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D008628:Mercury; D045663:Quantum Dots; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000295:instrumentation* / Q000379:methods
chemical_list: D006108:Graphite; D008628:Mercury; D005978:Glutathione
keywords: food samples; g-CNQDs; glutathione; switch-on fluorescence