title: Copper nanocluster coupling europium as an off-to-on fluorescence probe for the determination of phosphate ion in water samples.
abstract: This paper reports an "off-to-on" fluorescence (FL) probe for sensitively and selectively detecting phosphate ions (Pi's). Fabrication of the probe was based on the competition between Pi's and tannic acid-stabilized copper nanoclusters (TA-Cu NCs) for Eu(3+) binding. The addition of Eu(3+) ions to TA-Cu NCs triggered the aggregation of TA-Cu NCs, which quenched the FL of TA-Cu NCs. After Pi addition, the aggregated TA-Cu NCs solubilized into the aqueous solution to facilitate the Pi-triggered dispersion of TA-Cu NCs. This phenomenon was due to the stronger binding ability between Pi's and Eu(3+) than that between TA and Eu(3+), leading to FL recovery of Cu NCs. The degree of redispersion of TA-Cu NCs was directly related to Pi concentration. Thus, Pi concentration can be quantitatively determined by the change in FL of the TA-Cu NCs dispersion. Under the optimized conditions, the change in FL presented a linear relationship with Pi concentration from 0.07 μmol L(-1) to 80 μmol L(-1). The limit of detection for Pi was 9.6×10(-3) μmol L(-1) at a signal-to-noise ratio of 3. For Pi determination in real samples, only 1 mL water sample was needed. The proposed probe was highly sensitive, free from the interference of other common species in aqueous media, and particularly useful for the fast and simple diagnosis of water-eutrophication extent.
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China; Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, PR China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Cao
authors.affiliation: Basic Department of Rongchang Campus, Southwest University, Chongqing 402460, PR China.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China. Electronic address: yuminghuang2000@yahoo.com.
authors.forename: Yuming
authors.initials: Y
authors.lastname: Huang
mesh_terms: D003300:Copper / Q000737:chemistry*; D005063:Europium / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D060106:Lakes / Q000032:analysis; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry*; D010710:Phosphates / Q000032:analysis*; D045483:Rivers / Q000737:chemistry; D013634:Tannins / Q000737:chemistry*; D062065:Wastewater / Q000032:analysis
chemical_list: D003300:Copper; D005063:Europium; D005456:Fluorescent Dyes; D010710:Phosphates; D013634:Tannins; D062065:Wastewater
keywords: Copper nanoclusters; Fluorescence probe; Lanthanide ions; Phosphate ions