Rapid Quantification of 4,4'-Methylenedianiline by Surface-Enhanced Raman Spectroscopy.

Methylenedianiline (MDA) is a common industrial chemical with health and product safety concerns. Common analysis methods require many steps including extraction and derivatization ending in GC/MS or HPLC analysis, which minimize its use as an on-line or at-line technique. The procedure can take hours, prohibiting its use as a real-time decision-making tool as well as using valuable resources and laboratory space.

Structure enhancement factor relationships in single gold nanoantennas by surface-enhanced Raman excitation spectroscopy.

Determining the existence of any direct spectral relationship between the far-field scattering properties and the near-field Raman-enhancing properties of surface-enhanced Raman spectroscopy (SERS) substrates has been a challenging task with only a few significant results to date. Here, we prove that hot spot dominated systems show little dependence on the far-field scattering properties because of differences between near- and far-field localized surface plasmon resonance (LSPR) effects as well as excitation of new plasmon modes via a localized emitter. We directly probe the relationship between the near- and far-field light interactions using a correlated LSPR-transmission electron microscopy (TEM) surface-enhanced Raman excitation spectroscopy (SERES) technique.

A semiconducting organic radical cationic host-guest complex.

The self-assembly and solid-state semiconducting properties of single crystals of a trisradical tricationic complex composed of the diradical dicationic cyclobis(paraquat-p-phenylene) (CBPQT(2(•+))) ring and methyl viologen radical cation (MV(•+)) are reported. An organic field effect transistor incorporating single crystals of the CBPQT(2(•+))⊂MV(•+) complex was constructed using lithographic techniques on a silicon substrate and shown to exhibit p-type semiconductivity with a mobility of 0.05 cm(2) V(-1) s(-1).

Creating, characterizing, and controlling chemistry with SERS hot spots.

In this perspective we discuss the roles of hot spots in surface-enhanced Raman spectroscopy (SERS). After giving background and defining the hot spot, we evaluate a variety of SERS substrates which often contain hot spots. We compare and discuss the differentiating properties of each substrate.

Surface-Enhanced Raman Spectroelectrochemistry of TTF-Modified Self-Assembled Monolayers.

Surface-enhanced Raman spectroscopy (SERS) was used to monitor the response of a self-assembled monolayer (SAM) of a tetrathiafulvalene (TTF) derivative on a gold film-over-nanosphere electrode. The electrochemical response observed was rationalized in terms of the interactions between TTF moieties as the oxidation state was changed. Electrochemical oxidation to form the monocation caused the absorbance of the TTF unit to coincide with both the laser excitation wavelength and the localized surface plasmon resonance (LSPR), resulting in surface-enhanced resonance Raman scattering (SERRS).

Single-molecule surface-enhanced Raman spectroscopy of crystal violet isotopologues: theory and experiment.

Single-molecule surface-enhanced Raman spectroscopy (SMSERS) of crystal violet (CV) has been reported since 1997, yet others have offered alternative explanations that do not necessarily imply SMSERS. Recently, the isotopologue approach, a statistically significant method to establish SMSERS, has been implemented for members of the rhodamine dye family. We provide the first demonstration of SMSERS of a triphenylmethane dye using the isotopologue approach.

Surface-enhanced Raman excitation spectroscopy of a single rhodamine 6G molecule.

The surface-enhanced Raman excitation profiles (REPs) of rhodamine 6G (R6G) on Ag surfaces are studied using a tunable optical parametric oscillator excitation source and versatile detection scheme. These experiments afford the ability to finely tune the excitation wavelength near the molecular resonance of R6G (i.e.