title: Rhodamine 6G conjugated-quantum dots used for highly sensitive and selective ratiometric fluorescence sensor of glutathione.
abstract: Rhodamine 6G (R6G) and 3-mercaptopropionic acid (MPA) capped-CdTe quantum dots (QDs) were conjugated by electrostatic interactions in aqueous solution. The R6G-QDs conjugate was utilized as a photoluminescence (PL) ratiometric sensor for the detection of glutathione (GSH). In this method, intentional introduction of GSH destroyed the conjugation of R6G and QDs, and induced regular PL change of R6G-QDs conjugates due to the competitive chelation between GSH and MPA ligand on the surface of QDs. The ratio of PL intensity of R6G (I(R6G)) to that of QDs (I(QDs)) in this conjugate was near linear toward the concentration of GSH in the range from 0.05 to 80 μM, and corresponding regression equation showed a good linear coefficient of 0.9954. The limit of detection of 15 nM in this proposed method was about 40-fold lower than that of other QDs-based PL sensors. Interferential experiments testified that R6G-QDs conjugates-based ratiometric PL sensor of GSH showed high selectivity over other related thiols and amino acids. Real sample assays further verified perfect analysis performance of the PL sensor of GSH. In comparison with conventional analytical techniques for the measurement of GSH, this ratiometric PL sensor was facile, economic, highly sensitive and selective.
authors.affiliation: Department of Physical Chemistry, College of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
authors.forename: Rijun
authors.initials: R
authors.lastname: Gui
authors.forename: Xueqin
authors.initials: X
authors.lastname: An
authors.forename: Hongjuan
authors.initials: H
authors.lastname: Su
authors.forename: Weiguo
authors.initials: W
authors.lastname: Shen
authors.forename: Linyong
authors.initials: L
authors.lastname: Zhu
authors.forename: Xingyuan
authors.initials: X
authors.lastname: Ma
authors.forename: Zhiyun
authors.initials: Z
authors.lastname: Chen
authors.forename: Xiaoyong
authors.initials: X
authors.lastname: Wang
mesh_terms: D015097:3-Mercaptopropionic Acid / Q000737:chemistry*; D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D001667:Binding, Competitive; D002104:Cadmium / Q000737:chemistry; D002417:Cattle; D005453:Fluorescence; D005978:Glutathione / Q000032:analysis*; D057230:Limit of Detection; D008081:Liposomes / Q000737:chemistry; D045663:Quantum Dots; D012044:Regression Analysis; D012235:Rhodamines / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D055672:Static Electricity; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013691:Tellurium / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D008081:Liposomes; D012235:Rhodamines; D013438:Sulfhydryl Compounds; D002104:Cadmium; C026188:rhodamine 6G; D014867:Water; D012710:Serum Albumin, Bovine; D015097:3-Mercaptopropionic Acid; D005978:Glutathione; D013691:Tellurium