title: Hydrothermal synthetic mercaptopropionic acid stabled CdTe quantum dots as fluorescent probes for detection of Ag⁺.
abstract: Mercaptopropionic acid (MPA) capped CdTe quantum dots (QDs) with particle size 3 nm have been successfully synthesized in aqueous medium by hydrothermal synthesis method. And the effects of different metal ions on MPA capped CdTe QDs fluorescence were studied using fluorescence spectrometry. The results demonstrated that at the same concentration level, Ag(+) could strongly quench CdTe QDs fluorescence, and the other metal ions had little effect on CdTe QDs fluorescence except Cu(2+). On the basis of this fact, a rapid, simple, highly sensitive and selective method based on fluorescence quenching principle for Ag(+) detection in aqueous solution was proposed. Under optimal conditions, the quenched fluorescence intensity (F(0)-F) increased linearly with the concentration of Ag(+) ranging from 4 × 10(-7) to 32 × 10(-7)mol L(-1). The limit of detection for Ag(+) was 4.106 × 10(-8)mol L(-1). The obtained plot of F(0)/F versus [Ag(+)] was an upward curvature, concave towards the y-axis, rather than a straight line. The modified form of the Stern-Volmer equation was third order in Ag(+) concentration. According to the modified Stern-Volmer equation, it can be inferred that dynamic quenching and static quenching simultaneously occurred when Ag(+) interacted with MPA capped CdTe QDs. At the same time other factors might also influence the quenching process. Based on this study, hydrothermal synthesized MPA capped CdTe QDs with particle size 3 nm may be used as a novel fluorescence probe to quantificationally and selectively detect Ag(+).
authors.affiliation: Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Gan
authors.forename: Yu-Jun
authors.initials: YJ
authors.lastname: Zhang
authors.forename: Nan-Jing
authors.initials: NJ
authors.lastname: Zhao
authors.forename: Xue
authors.initials: X
authors.lastname: Xiao
authors.forename: Gao-Fang
authors.initials: GF
authors.lastname: Yin
authors.forename: Shao-Hui
authors.initials: SH
authors.lastname: Yu
authors.forename: Huan-Bo
authors.initials: HB
authors.lastname: Wang
authors.forename: Jing-Bo
authors.initials: JB
authors.lastname: Duan
authors.forename: Chao-Yi
authors.initials: CY
authors.lastname: Shi
authors.forename: Wen-Qing
authors.initials: WQ
authors.lastname: Liu
mesh_terms: D015097:3-Mercaptopropionic Acid / Q000737:chemistry; D019187:Cadmium Compounds / Q000737:chemistry*; D002414:Cations, Monovalent / Q000032:analysis; D005456:Fluorescent Dyes / Q000737:chemistry*; D057230:Limit of Detection; D010316:Particle Size; D045663:Quantum Dots; D012834:Silver / Q000032:analysis*; D013050:Spectrometry, Fluorescence / Q000379:methods; D013691:Tellurium / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D002414:Cations, Monovalent; D005456:Fluorescent Dyes; D012834:Silver; D015097:3-Mercaptopropionic Acid; D013691:Tellurium; C028337:cadmium telluride