title: Determination of trace amounts of mercury using hierarchically nanostructured europium oxide.
abstract: This work reports a highly sensitive procedure for the determination of trace amounts of mercury, based on fluorescence quenching of thenoyltrifluoroacetone (TTA) capped hierarchically nanostructured europium oxide (cHN-Eu(2)O(3)). The HN-Eu(2)O(3) consisted of nanometer-thick Eu(2)O(3) sheets self-organized into nano- and micro-sized monoliths with a hierarchical architecture while retaining its desirable fluorescence properties. The fluorescence intensity of the cHN-Eu(2)O(3) was 1000 times higher than that of commercial Eu(2)O(3) nanoparticles (equivalent weight) when it was capped with TTA, suggesting that a synergetic effect, confining the longtime Eu(3+) excitation within the nanostructure and light-harvesting effect of the capping agent, is responsible for this fluorescence enhancement. Excellent interaction between the cHN-Eu(2)O(3) and solution species is expected owing to its large surface area, high surface-to-bulk ratio, and ultrahigh fluorescence intensity. As an example, aqueous suspensions of the cHN-Eu(2)O(3) were used as sensing agent for the determination of trace amounts of mercury. A linear relationship between the concentration of mercury and fluorescence quenching was observed from 10 ppb to 10 ppm with a correlation coefficient of 0.997 and a detection limit of 5.0 ppb. Mercury in various samples was analyzed using the cHN-Eu(2)O(3) suspension.
authors.affiliation: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, Singapore 138669, Singapore.
authors.forename: Yanfen
authors.initials: Y
authors.lastname: Peng
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Chen
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Gao
mesh_terms: D000818:Animals; D004785:Environmental Pollutants / Q000032:analysis*; D005063:Europium / Q000737:chemistry*; D005399:Fishes / Q000378:metabolism; D006197:Hair / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D012015:Reference Standards; D012758:Shellfish / Q000032:analysis; D013050:Spectrometry, Fluorescence / Q000379:methods; D013499:Surface Properties
chemical_list: D004785:Environmental Pollutants; D010087:Oxides; D005063:Europium; D008628:Mercury