title: Incorporation of the fluoride induced Si-O bond cleavage and functionalized gold nanoparticle aggregation into one colorimetric probe for highly specific and sensitive detection of fluoride.
abstract: A highly selective and sensitive probe was developed for the field test of F(-) in environmental waters. The probe was fabricated by anchoring 4-mercaptopyridine (MPD) on AuNPs via Au-S interaction to form MPD-AuNPs, and further assembling 3-aminopropyltrimethoxysilane (APTMS) on the surface of MPD-AuNPs. The hydrolysis and cross-link of APTMS resulted in a thin monolayer of Si-O-Si protecting layer to encapsulated MPD-AuNPs. In the assay, F(-) reacted with Si-O bond and thus destroyed the outer protecting layer of the probe, and further triggered the aggregation of internal MPD-AuNPs by forming N-H-F hydrogen bond. The F(-) induced aggregation of functionalized AuNPs gave rise to significant solution color switch from red to blue, which facilitated visual assay of F(-) in the range of 1.0-7.0 μg mL(-1) by naked eyes. The probe is able to discriminate F(-) from a wide range of environmentally dominant ions, thus it can be applied to detect F(-) in drinkable water with satisfactory results that is agreed well with that of using ion chromatography.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
authors.forename: Jie-Fang
authors.initials: JF
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China. Electronic address: jfliu@rcees.ac.cn.
authors.forename: Rui
authors.initials: R
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
authors.forename: Zhong-Mian
authors.initials: ZM
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
authors.forename: Jing-Fu
authors.initials: JF
authors.lastname: Liu
mesh_terms: D003124:Colorimetry / Q000379:methods*; D005459:Fluorides / Q000032:analysis* / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006868:Hydrolysis; D053768:Metal Nanoparticles / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D011437:Propylamines / Q000737:chemistry; D011725:Pyridines / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D011437:Propylamines; D011725:Pyridines; D012821:Silanes; C088294:3-aminopropyltrimethoxysilane; C042861:4-thiopyridine; D006046:Gold; D005459:Fluorides; D010100:Oxygen; D012825:Silicon
keywords: Colorimetric probe; Fluoride; Gold nanoparticles; Hydrogen bonding; Specific chemical reaction