title: Ethylene Diamine Tetraacetic Acid Etched Quantum Dots as a "Turn-On" Fluorescence Probe for Detection of Trace Zinc in Food.
abstract: In the present paper, a simple and rapid "turn-on" fluorescence sensor for Zn2+ based on ethylene diamine tetraacetic acid (EDTA) etched CdTe quantum dots (QDs) was developed. First, the initial bright fluorescence of mercaptopropionic acid (MPA) capped CdTe QDs was effectively quenched by EDTA, and then the presence of Zn2+ could "turn on" the weak fluorescence of QDs quenched by EDTA due to the formation of ZnS passivation shell. The increase of fluorescence intensity of EDTA etched QDs was found to be linear with the concentration of Zn2+ added. Under the optimum conditions, the calibration curve of this method showed good linearity in the concentration range of 9.1-1 09.1 μM of Zn2+ with the correlation coefficient R2 = 0.998. The limit of detection (3σ/K) was 2 μM. The developed QDs-based sensor was successfully applied to detect trace zinc in zinc fortified table salts and energy drinks with satisfactory results.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Fangdi
authors.initials: F
authors.lastname: Wei
authors.forename: Guanhong
authors.initials: G
authors.lastname: Xu
authors.forename: Yanzi
authors.initials: Y
authors.lastname: Wu
authors.forename: Chunting
authors.initials: C
authors.lastname: Hu
authors.forename: Quan
authors.initials: Q
authors.lastname: Song
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.forename: Qin
authors.initials: Q
authors.lastname: Hu
mesh_terms: D002021:Buffers; D004492:Edetic Acid / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D005504:Food Analysis / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D011422:Propionates / Q000737:chemistry; D045663:Quantum Dots / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D015032:Zinc / Q000032:analysis* / Q000737:chemistry*
chemical_list: D002021:Buffers; D005456:Fluorescent Dyes; D011422:Propionates; D004492:Edetic Acid; D015032:Zinc; C029658:propionic acid