Surface‐enhanced Raman scattering of 4,4′‐dicyanobiphenyl on gold and silver nanoparticle surfaces

Abstract

The adsorption behavior of 4,4 -dicyanobiphenyl (DCBP) on Ag and Au nanoparticle surfaces was studied by surface-enhanced Raman scattering (SERS). The absence of the ring CH band denoted a flat orientation of the biphenyl ring on Ag and Au. The red shift of the n 8a band indicated a direct ring p-orbital interaction with the surfaces. The two benzene rings of DCBP appeared to lie on the same plane with a p-type interaction upon adsorption on the surfaces. The n(CN) bands were blue shifted in the Ag and Au SERS spectra by 2 and 22 cm −1 , respectively from the ordinary Raman spectrum. The orientation of DCBP on the Ag and Au surfaces was analyzed by the relative enhancement factors of the vibrational bands based on the electromagnetic SERS selection rule.

Electric Field-induced Charge Transfer of (Bu4N)2[Ru(dcbpyH)2-(NCS)2] on Gold, Silver, and Copper Electrode Surfaces Investigated by Means of Surface-enhanced Raman Scattering

“…[20][21][22][23][24][25][26][27] Recently a density functional theory study was performed to investigate the adsorption of alkanethiols on Cu, Ag, and Au surfaces, predicting dissimilar ionic characteristics depending on the metal substrates. 28 Solvent dependent charge transfer of the ruthenium bipyridine (Ru-bpy) dye on colloidal Ag and Au surface has been recently reported by means of SERS.…”

“…28 Solvent dependent charge transfer of the ruthenium bipyridine (Ru-bpy) dye on colloidal Ag and Au surface has been recently reported by means of SERS. 29 Although quite a few studies have explored the different adsorption structures of SAMs on metal surfaces, [20][21][22][23][24][25][26][27][28] no reports have investigated ruthenium bipyridine (Ru-bpy) dye on metal surfaces using potential dependent vibrational spectroscopy.…”

Adsorption Characteristics and Structure of 4,4'-Bis(mercaptomethyl)biphenyl on Silver by Surface-enhanced Raman Scattering and Density Functional Theory Calculations

“…7 In this regard, the correlations between molecular structures and charge transport properties needed to be comprehended and hence the studies on the structure and orientation of molecules linked on the metal have been investigated experimentally and theoretically. [8][9][10][11][12][13] 4,4'-Biphenyl dicyanide is flatly adsorbed on both Ag and Au through direct interaction between the π-systems of the phenyl rings and the metal. 8 4,4'-Biphenyl diisocyanide is, however, known to be bridged between the two gold nanoparticles at low concentrations whereas it should be vertically bonded on gold via one of the two isocyanide groups at higher concentrations.…”

“…[8][9][10][11][12][13] 4,4'-Biphenyl dicyanide is flatly adsorbed on both Ag and Au through direct interaction between the π-systems of the phenyl rings and the metal. 8 4,4'-Biphenyl diisocyanide is, however, known to be bridged between the two gold nanoparticles at low concentrations whereas it should be vertically bonded on gold via one of the two isocyanide groups at higher concentrations. 9 Aromatic dithiols as well as aliphatic dithiols are usually adsorbed on the Au surface as a monolayer by forming only a single S-Au bond, while they are adsorbed forming the two S-Ag bonds on the Ag surface.…”

pH-Dependent surface-enhanced resonance Raman scattering of yeast iso-1-cytochrome c adsorbed on silver nanoparticle surfaces under denaturing conditions at pH < 3

“…Chemically-specific information is provided by unique vibrational modes of target adsorbates, which depends on the metal substrates (19)(20)(21)(22)(23). However, the detailed adsorption characteristics on metal surfaces have not been fully clarified.…”