A New Surface for Surface-Enhanced Infrared Spectroscopy:  Tin Island Films

Abstract

For the first time, it has been observed that tin island films used in surface infrared experiments give rise to an electromagnetic enhancement of the infrared absorption spectrum. The surface enhancement of the infrared (SEIR) absorption by tin island films is shown for evaporated nanometric films of 5,14-pentacenedione (Q2) and naphthalic 1,8:4,5-dianhydride (NTCDA). The experiments and spectral characteristics demonstrating the ability of tin to produce SEIR of organic molecules physically adsorbed onto tin structures are described. Tin island films of varying mass thickness were fabricated to ascertain maximum enhancement. Their morphology was determined by transmission electron microscopy. Comparisons are made between the SEIR spectra on rough tin and on silver surfaces and the corresponding reflection-absorption spectra (RAIRS) obtained for the same organic molecules on reflecting surfaces of tin and silver.

Spectroscopic Study of Tetradecyltrimethylammonium Bromide Pt−C14TAB Nanoparticles: Structure and Stability

“…Tetradecyltrimethylammonium bromide or C 14 TAB is an ionic, amphiphilic surfactant, and the electrostatic interactions with the metallic surface play a dominant role in stabilizing nanoparticles. The tetrahedral cation N + is isoelectronic and structurally equivalent to carbon in the sp 3 state and is unable to participate in donor-acceptor interactions.…”

Surface-Enhanced Infrared Absorption

“…In contrast, the EM calculations predict an enhancement of infrared absorption on transition metals as strong as that on coinage metals [26]. In fact, several recent experiments have demonstrated the SEIRA effect on many other metals such as Pt, Pd, Rh, Ru, Ir, Sn, Fe, In, Pb, and Pt-Fe alloys [16,17,19,32,49,50,70,71,72,73]. Since the dielectric constants of these metals do not differ greatly from those of coinage metals in the infrared region, these results may be a reasonable consequence.…”

“…It is emphasized that SEIRAS and SERS are not competitive but are supplementary to one other, as in the case of normal infrared and Raman spectroscopy. A comparison of SEIRA and SERS spectra is very helpful for detailed analysis of both spectra [42,44,72]. The use of SEIRAS in tandem with other analytical techniques will also be very fruitful for surface chemistry and surface electrochemistry, as described in Sect.…”

Attenuated Total Reflection Surface-Enhanced Infrared Absorption Spectroscopy: a Powerful Technique for Bioanalysis

“…Remarkably, to generate the absorption, the orientation of dipole moment should be parallel to the light polarization [13]. In principle, two basic mechanisms are commonly used to explain the enhanced IR signal from Eq.…”

“…Metals meet the condition that the real part of the dielectric function is larger than the imaginary component [15] like Al [32], Pt [33], Pd [33,34], Ru [33], Rh [33], Sn [13], Ni [35,36], Pb [37] can also be used as SEIRAS substrates. Since the substrates sometimes are used as working electrode, the variety of material choices extremely enriches the applications for ATR-SEIRAS.…”