title: Colorimetric Au nanoparticle probe for speciation test of arsenite and arsenate inspired by selective interaction between phosphonium ionic liquid and arsenite.
abstract: The exposure of millions of people to unsafe levels of arsenite (AsIII) and arsenate (AsV) in drinking waters calls for the development of low-cost methods for on-site monitoring these two arsenic species in waters. Herein, for the first time, tetradecyl (trihexyl) phosphonium chloride ionic liquid was found to selectively bind with AsIII via extended X-ray absorption fine structure (EXAFS) analysis. Based on the finding, an AsIII-specific probe was developed by modifying gold nanoparticles with the ionic liquid. Futhermore, Hofmeister effect was primarily observed to significantly affect the sensitivity of gold nanoparticle probe. With the colorimetric probe, we developed a protocol for naked eye speciation test of AsIII and AsV at levels below the World Health Organization (WHO) guideline of 10 μg L(-1). This method featured with high tolerance to common coexisting ions such as 10 mM PO4(3-), and was validated by assaying certified reference and environmental water samples.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Tan
authors.forename: Jing-Fu
authors.initials: JF
authors.lastname: Liu
authors.forename: Yong-Guang
authors.initials: YG
authors.lastname: Yin
authors.forename: Qian-Tao
authors.initials: QT
authors.lastname: Shi
authors.forename: Chuan-Yong
authors.initials: CY
authors.lastname: Jing
authors.forename: Gui-Bin
authors.initials: GB
authors.lastname: Jiang
mesh_terms: D001149:Arsenates / Q000737:chemistry / Q000302:isolation & purification*; D018053:Arsenites / Q000737:chemistry / Q000302:isolation & purification*; D003124:Colorimetry; D006046:Gold / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D010757:Phosphorous Acids; D014867:Water / Q000737:chemistry
chemical_list: D001149:Arsenates; D018053:Arsenites; D052578:Ionic Liquids; D010757:Phosphorous Acids; D014867:Water; D006046:Gold; C015001:arsenite; C025657:arsenic acid
keywords: Hofmeister effect; arsenic; gold nanoparticle; interaction; ionic liquid; visual test