title: Specific behavior of the p-aminothiophenol--silver sol system in their Ultra-Violet-Visible (UV-Visible) and Surface Enhanced Raman (SERS) spectra.
abstract: The UV-Visible and Surface Enhanced Raman Spectroscopy (SERS) behavior of silver sol (a typical SERS agent) were studied in the presence of different bifunctional thiols such as p-aminothiophenol, p-mercaptobenzoic acid, p-nitrothiophenol, p-aminothiophenol hydrochloride, and 2-mercaptoethylamine hydrochloride in diluted aqueous solution. Our results confirm that the p-aminothiophenol induced aggregation of citrate stabilized silver colloid originates from its electrostatic nature, as well as the azo-bridge formation cannot be the reason of the observed time dependent UV-Visible spectra. Based on our parallel SERS and electrospray ionization mass spectrometry measurements, we have concluded that certain amount of oxidized form of the probe molecule has to be present for the so-called b2-mode enhancement in the SERS spectrum of p-aminothiophenol. Our findings seem to support the idea that the azo-bridge formation is responsible for the b2-mode enhancement in the SERS spectrum of p-aminothiophenol.
authors.affiliation: Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Pusztaszeri út 59-67, 1025 Budapest, Hungary. Electronic address: firkala.tamas@ttk.mta.hu.
authors.forename: Tamás
authors.initials: T
authors.lastname: Firkala
authors.forename: Emília
authors.initials: E
authors.lastname: Tálas
authors.forename: Judith
authors.initials: J
authors.lastname: Mihály
authors.forename: Tímea
authors.initials: T
authors.lastname: Imre
authors.forename: Sándor
authors.initials: S
authors.lastname: Kristyán
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D015394:Molecular Structure; D012834:Silver / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000814:Aniline Compounds; D013438:Sulfhydryl Compounds; D012834:Silver; C064316:4-aminothiophenol
keywords: 2-Mercaptoethylamine hydrochloride; Azo-formation; Silver colloid; Surface Enhanced Raman Spectroscopy; Time dependent UV–Visible spectra; b(2)-Mode enhancement; p-Aminothiophenol