title: Detection of mercury ions (II) based on non-cross-linking aggregation of double-stranded DNA modified gold nanoparticles by resonance Rayleigh scattering method.
abstract: This work describes a sensitive approach utilizing non-cross-linking aggregation of double-stranded DNA modified gold nanoparticles (dsDNA-AuNPs) for the detection of mercury ions (Hg(2+)) by resonance Rayleigh scattering (RRS) method for the first time. The double-stranded DNA contains a mismatched T-T base pair in the chain terminus, resulting in a flexible DNA tail and preventing the AuNPs from aggregation. Thus, a low RRS signal is obtained. However, in the presence of Hg(2+), the non-cross-linking aggregation of dsDNA-AuNPs occurs, due to the Hg(2+)-mediated coordination of T-Hg(2+)-T base pair. The aggregation of nanoparticles generates a high RRS value. Particularly, the solution color and ultraviolet-visible absorption barely changed under the same conditions, while it is capable of detecting by RRS method with a low detection limit (0.4nM), which is 1000-fold lower than that of the colorimetric method. The proposed method was successfully applied to the detection of Hg(2+) in real samples. The sensitive and selective assay might be inspiring for the development of new detectors for other metal ions or biomolecules.
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Zhong Feng
authors.initials: ZF
authors.lastname: Gao
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Wei Wei
authors.initials: WW
authors.lastname: Song
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China. Electronic address: luohq@swu.edu.cn.
authors.forename: Hong Qun
authors.initials: HQ
authors.lastname: Luo
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China. Electronic address: linb@swu.edu.cn.
authors.forename: Nian Bing
authors.initials: NB
authors.lastname: Li
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D002413:Cations, Divalent / Q000032:analysis; D004247:DNA / Q000737:chemistry*; D060766:Drinking Water / Q000032:analysis*; D000067493:Dynamic Light Scattering / Q000379:methods; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis*; D053768:Metal Nanoparticles / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D002413:Cations, Divalent; D060766:Drinking Water; D014874:Water Pollutants, Chemical; D006046:Gold; D004247:DNA; D008628:Mercury
keywords: DNA; Gold nanoparticles; Mercury ion; Resonance Rayleigh scattering