title: Vertically aligned Ag nanoplate-assembled film as a sensitive and reproducible SERS substrate for the detection of PCB-77.
abstract: Vertically aligned Ag nanoplate-assembled film has been achieved by spin-coating Ag seeds on an ITO substrate and subsequent electrodeposition in a mixed aqueous solution of AgNO(3) and citric acid. As sufficient hot spots are located in the deep gaps between the neighboring nanoplates across the whole substrate, the Ag nanoplate-assembled film shows strong Surface enhanced Raman scattering (SERS) effect, together with good signal reproducibility. Therefore, the Ag nanoplate-assembled films were tried as robust, highly sensitive and reproducible SERS substrates for the rapid detection of 3,3',4,4'-tetrachlorobiphenyl (PCB-77) and a detection limit of about 10(-6)M was reached. For further reducing the detection limit, a layer of decanethiol was modified on the Ag nanoplate surface to capture the PCB-77 molecules efficiently, and a lower detection limit of 10(-7)M was achieved. A linear dependence was found between the logarithmic concentrations of PCB-77 and the intensities of the fingerprint peaks. Furthermore, the Ag nanoplate-assembled film can also be used as a SERS substrate to distinguish characteristic peaks of different polychlorinated biphenyls (PCBs) in their mixed solutions. Therefore the vertically aligned Ag nanoplate-assembled film has potentials as effective SERS substrates in rapid and direct detection of trace PCBs.
authors.affiliation: Key Laboratory of Materials Physics, and Anhui Key Laboratory of Nanomaterials and Nanostructures, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Chuhong
authors.initials: C
authors.lastname: Zhu
authors.forename: Guowen
authors.initials: G
authors.lastname: Meng
authors.forename: Qing
authors.initials: Q
authors.lastname: Huang
authors.forename: Zhulin
authors.initials: Z
authors.lastname: Huang
mesh_terms: D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods; D004785:Environmental Pollutants / Q000032:analysis* / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D011078:Polychlorinated Biphenyls / Q000032:analysis* / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman
chemical_list: D004785:Environmental Pollutants; D012834:Silver; D011078:Polychlorinated Biphenyls; C028451:3,4,3',4'-tetrachlorobiphenyl