title: "Turn-on" fluorescence detection of lead ions based on accelerated leaching of gold nanoparticles on the surface of graphene.
abstract: A novel platform for effective "turn-on" fluorescence sensing of lead ions (Pb(2+)) in aqueous solution was developed based on gold nanoparticle (AuNP)-functionalized graphene. The AuNP-functionalized graphene exhibited minimal background fluorescence because of the extraordinarily high quenching ability of AuNPs. Interestingly, the AuNP-functionalized graphene underwent fluorescence restoration as well as significant enhancement upon adding Pb(2+), which was attributed to the fact that Pb(2+) could accelerate the leaching rate of the AuNPs on graphene surfaces in the presence of both thiosulfate (S(2)O(3)(2-)) and 2-mercaptoethanol (2-ME). Consequently, this could be utilized as the basis for selective detection of Pb(2+). With the optimum conditions chosen, the relative fluorescence intensity showed good linearity versus logarithm concentration of Pb(2+) in the range of 50-1000 nM (R = 0.9982), and a detection limit of 10 nM. High selectivity over common coexistent metal ions was also demonstrated. The practical application had been carried out for determination of Pb(2+) in tap water and mineral water samples. The Pb(2+)-specific "turn-on" fluorescence sensor, based on Pb(2+) accelerated leaching of AuNPs on the surface of graphene, provided new opportunities for highly sensitive and selective Pb(2+) detection in aqueous media.
authors.affiliation: Key Laboratory of Coastal Zone Environmental Processes, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Fu
authors.forename: Tingting
authors.initials: T
authors.lastname: Lou
authors.forename: Zhaopeng
authors.initials: Z
authors.lastname: Chen
authors.forename: Meng
authors.initials: M
authors.lastname: Lin
authors.forename: Weiwei
authors.initials: W
authors.lastname: Feng
authors.forename: Lingxin
authors.initials: L
authors.lastname: Chen
mesh_terms: D005618:Fresh Water / Q000032:analysis; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000737:chemistry; D007854:Lead / Q000032:analysis*; D008623:Mercaptoethanol / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013499:Surface Properties; D013885:Thiosulfates / Q000737:chemistry
chemical_list: D007477:Ions; D013885:Thiosulfates; D007854:Lead; D008623:Mercaptoethanol; D006046:Gold; D006108:Graphite