Synthesis of a I super(2)-cyclodextrin-modified Ag film by the galvanic displacement on copper foil for SERS detection of PCBs

• Published in: Journal of colloid and interface science Vol. 365; no. 1; pp. 122 - 126
• Main Authors: Yuan, Jingpeng, Lai, Yongchao, Duan, Junling, Zhao, Quanqin, Zhan, Jinhua
• Format: Journal Article
• Language: English
• Published: 01.01.2012
• Subjects: Cadmium; Copper; Diffraction; Displacement; Enrichment; Foils; Morphology; Silver
• ISSN: 0021-9797
• DOI: 10.1016/j.jcis.2011.08.075

A mono-6-thio-I super(2)-cyclodextrin-modified silver film was synthesized via galvanic displacement on copper foil. The prepared silver films could enrich non-polar polychlorinated biphenyls (PCBs) molecules from hydrophilic phase using thiolate I super(2)-cyclodextrins (SH-I super(2)-CDs) as receptors. The components of as-prepared Ag-coated-Cu (Ag-Cu) film were confirmed by powder X-ray diffraction (XRD). Both surface-enhanced Raman spectroscopy (SERS) and energy dispersive X-ray spectroscopy (EDS) measurements gave strong evidences that the thiolated I super(2)-cyclodextrins (SH-I super(2)-CDs) had been immobilized on the surface of silver film. Compared to the substrates prepared in the absence of SH-I super(2)-CD, the surface morphology of the CD-modified Ag films was obviously changed. The interfacial enrichment and the capability of substrates to form inclusion complexes with PCBs molecules were tested by using PCB-15 (4,4\'-dichlorobiphenyl) as the probe molecules via SERS technique. The measured SERS spectra could distinguish the PCB-15 molecules at micro-molar level according to the most intense CCC bending in-plane mode of PCBs. The enhancement factor (EF) of the SERS substrates for PCB-15 was 1.2 x 10 super(5, which was comparable with a number of previous reports.)