title: β-Cyclodextrin coated SiO₂@Au@Ag core-shell nanoparticles for SERS detection of PCBs.
abstract: A new type of surface-enhanced Raman scattering (SERS) substrate consisting of β-cyclodextrin (β-CD) coated SiO2@Au@Ag nanoparticles (SiO2@Au@Ag@CD NPs) has been achieved. Our protocol was a simplified approach as the fabrication and modification of the silver shell were realized in a single-step reaction by taking advantage of β-CD as both the reducing and stabilizing agents. The as-synthesized SiO2@Au@Ag@CD NPs were uniform in size and demonstrated high SERS activity and reproducibility. The substrates consisting of the SiO2@Au@Ag@CD NPs were employed for SERS detection of polychlorinated biphenyls (PCBs) including PCB-3, PCB-29 and PCB-77. The SERS detection sensitivity was significantly improved due to enrichment of more PCB molecules captured by β-CD on the substrate surface, as confirmed by the appearance of the new Raman bands which are attributed to the complexes between β-CD and PCBs according to the theoretical simulation. Therefore, this work presents a novel approach to the fabrication of effective SERS substrates that can be employed for rapid determination of trace amounts of PCBs in the environment with high detection sensitivity and recognition selectivity.
authors.affiliation: Key Laboratory of Ion Beam Bioengineering, Institute of Technical Biology and Agriculture Engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, China. huangq@ipp.ac.cn.
authors.forename: Yilin
authors.initials: Y
authors.lastname: Lu
authors.forename: Guohua
authors.initials: G
authors.lastname: Yao
authors.forename: Kexi
authors.initials: K
authors.lastname: Sun
authors.forename: Qing
authors.initials: Q
authors.lastname: Huang
mesh_terms: D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D015203:Reproducibility of Results; D012822:Silicon Dioxide / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D047392:beta-Cyclodextrins; D012834:Silver; D006046:Gold; D012822:Silicon Dioxide; D011078:Polychlorinated Biphenyls; C031215:betadex