title: Colorimetric detection of trace copper ions based on catalytic leaching of silver-coated gold nanoparticles.
abstract: A colorimetric, label-free, and nonaggregation-based silver coated gold nanoparticles (Ag/Au NPs) probe has been developed for detection of trace Cu(2+) in aqueous solution, based on the fact that Cu(2+) can accelerate the leaching rate of Ag/Au NPs by thiosulfate (S(2)O(3)(2-)). The leaching of Ag/Au NPs would lead to dramatic decrease in the surface plasmon resonance (SPR) absorption as the size of Ag/Au NPs decreased. This colorimetric strategy based on size-dependence of nanoparticles during their leaching process provided a highly sensitive (1.0 nM) and selective detection toward Cu(2+), with a wide linear detection range (5-800 nM) over nearly 3 orders of magnitude. The cost-effective probe allows rapid and sensitive detection of trace Cu(2+) ions in water samples, indicating its potential applicability for the determination of copper in real samples.
authors.affiliation: Key Laboratory of Coastal Zone Environmental Processes, CAS, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Lou
authors.forename: Lingxin
authors.initials: L
authors.lastname: Chen
authors.forename: Zhaopeng
authors.initials: Z
authors.lastname: Chen
authors.forename: Yunqing
authors.initials: Y
authors.lastname: Wang
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
authors.forename: Jinhua
authors.initials: J
authors.lastname: Li
mesh_terms: D002384:Catalysis; D003124:Colorimetry / Q000295:instrumentation / Q000379:methods*; D003300:Copper / Q000032:analysis*; D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D012834:Silver / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D012834:Silver; D006046:Gold; D003300:Copper