title: Naked-eye sensor for rapid determination of mercury ion.
abstract: A naked-eye paper sensor for rapid determination of trace mercury ion in water samples was designed and demonstrated. The mercury-sensing rhodamine B thiolactone was immobilized in silica matrices and the silica matrices were impregnated firmly and uniformly in the filter paper. As water samples flow through the filter paper, the membrane color will change from white to purple red, which could be observed obviously with naked eye, when concentration of mercury ions equals to or exceeds 10nM, the maximum residue level in drinking water recommended by U.S. EPA. The color change can also be recorded by a flatbed scanner and then digitized, reducing the detection limit of Hg(2+) down to 1.2 nM. Moreover, this method is extremely specific for Hg(2+) and shows a high tolerance ratio of interferent coexisting ions. The presence of Na(+) (2 mM), K(+) (2 mM), Fe(3+) (0.1 mM), Zn(2+) (0.1 mM), Mg(2+) (0.1 mM), Ni(2+) (50 μM), Co(2+) (50 μM), Cd(2+) (50 μM), Pb(2+) (50 μM), Cu(2+) (50 μM) and Ag(+) (3.5 μM) did not interfere with the detection of Hg(2+) (25 nM). Finally, the present method was applied in the detection of Hg(2+) in mineral water, tap water and pond water.
authors.affiliation: Department of Instrumentation & Analytical Chemistry, Key Lab of Separation Science for Analytical Chemistry of CAS, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China; University of Chinese Academy of Sciences, Beijing 100039, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.forename: Dapeng
authors.initials: D
authors.lastname: Wu
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Yan
authors.forename: Yafeng
authors.initials: Y
authors.lastname: Guan
mesh_terms: D002413:Cations, Divalent; D003124:Colorimetry / Q000379:methods*; D060766:Drinking Water / Q000737:chemistry*; D005374:Filtration; D005618:Fresh Water / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D008628:Mercury / Q000302:isolation & purification*; D010209:Paper; D011934:Reagent Strips / Q000737:chemistry; D012235:Rhodamines / Q000737:chemistry*; D058428:Silica Gel; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D002413:Cations, Divalent; D060766:Drinking Water; D011934:Reagent Strips; D012235:Rhodamines; D014874:Water Pollutants, Chemical; C529525:rhodamine B thiolactone; D058428:Silica Gel; D008628:Mercury
keywords: Colorimetric; Filtration; Mercuric ion; Naked-eye