Chemical Raman Enhancement of Organic Adsorbates on Metal Surfaces

Abstract

Using first-principles theory and experiments, chemical contributions to surface-enhanced Raman spectroscopy for a well-studied organic molecule, benzene thiol, chemisorbed on planar Au(111) surfaces are explained and quantified. Density functional theory calculations of the static Raman tensor demonstrate a strong mode-dependent modification of benzene thiol Raman spectra by Au substrates. Raman active modes with the largest enhancements result from stronger contributions from Au to their electron-vibron coupling, as quantified through a deformation potential. A straightforward and general analysis is introduced to extract chemical enhancement from experiments for specific vibrational modes; measured values are in excellent agreement with our calculations.

Strong Core@Shell Dependence in Surface-Enhanced Raman Scattering of Pyridine on Stable 13-Atom Silver-Caged Bimetallic Clusters

“…Zayak and colleagues have confirmed that the intense electron exchange in the interface is beneficial to chemical enhancement. 65 In addition, we are surprised to find that the deformation density is obviously increased in the area between the core atom and the connected metal atom, especially for the W@Ag 12 -Py complex, although the change is most evident in all complexes. Yet, compared with complexes based on the Mo atom as the core, complexes using the W atom as the core show conspicuous improvement of the deformation density in the area between the core atom and the connected metal atom.…”

Modeling Coherent Anti-Stokes Raman Scattering with Time-Dependent Density Functional Theory: Vacuum and Surface Enhancement.

“…[46][47][48] Following previous that previous work, resonant signal in Eq. (1) should be proportional to the square of the Raman polarizability derivative, |( dα i j dQ k ) 2 | 2 .…”

Vapor phase SERS sensor based on mesoporous silica decorated with silver nanoparticles

“…At present, most of the research advantages for SERS in the analysis of gaseous and vapor phases are based on simple chemical sorption of analytes on a highly developed silver or gold surface if they have high affinity to plasmonic nanoparticles being, for example, thiol derivatives or other similar molecules [11,13,14,19,20,25,27,29]. Accordingly, the sensitivity of the analysis becomes even higher if porous silver nanocubes [12], polymer coatings [15], anisotropic nanoparticle aggregates [16,24], metal -organic frameworks [21,26], multihole capillaries [23], graphene oxide surface [28], free -surface microfluidic chips [18], electrodynamic precipitation [17] are applied.…”

“…At the same time, ordinary materials for SERS with ecological, pharmaceutical, biological and medical applications are commonly designed for the analysis of liquid analytes [1][2][3][4][5][6][7][8][9][10] while a limited number of actual research efforts has focused on vapor phase detection [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. The latter challenge evidently widens the promising application area of SERS and therefore requires novel approaches for the design of SERS-active materials.…”