SERRS dyes. Part I. Synthesis of benzotriazole monoazo dyes as model analytes for surface enhanced resonance Raman scattering

Abstract

The synthesis of seven monoazo benzotriazole dyes for use in surface enhanced resonance Raman scattering, SERRS, is reported. The dyes are all capable of complexing to the silver surface used to provide the surface enhancement found in SERRS and hence act as 'model' analytes. One dye was examined in detail and showed a quantitative relationship between concentration and signal intensity.

Surface-Enhanced Raman Scattering (SERS) and Surface-Enhanced Resonance Raman Scattering (SERRS): A Review of Applications

“…Although there is still considerable potential for development, some specific SERRS labeling chemistry has been developed. 18,19 Although changes in orientation of the analyte on the surface can be observed, they are generally less pronounced than for SERS.…”

Characterization of Novel Ag on TiO2 Films for Surface-Enhanced Raman Scattering

“…It is known that the benzotriazole moiety forms a polymeric silver complex with the surface of silver; indeed, benzotriazole itself is commonly used as an anti-tarnishing agent 28 . Work by our group has established that the attachment of the GM-19 dye onto silver is essentially irreversible and that the dye remains in position over a wide range of experimental conditions and concentrations, allowing highly reproducible analysis [23][24][25][26][27] . The dye is easily applied, typically as a weak methanolic solution (10 -6 M in this work); adsorption is almost 100% and the observed SERS signal is usually significant on SERS active substrates, due to the large spontaneous Raman cross-section of the dye.…”

“…DFT calculations, reported earlier have been used to assign these and the other, less prominent, vibrations 23 .…”

“…The SERS activities of all the Ag films described above were then tested using the SERS probe, benzotriazole dye: 3,5-dimethoxy-4-(5-azobenzotriazole) phenylamine, which will be referred to throughout as GM19, since it was the nineteenth benzotriazole derivative synthesised by the group for work with SERS and SERRS [23][24][25][26][27] . GM-19 has proved highly effective as a SERS and SERRS probe dye.…”

Surface enhanced Raman spectroscopy (SERS): Potential applications for disease detection and treatment

“…Although, non-invasivity is a key attraction of Raman spectroscopy, the overall outcome is that the technique is reliant on spectral signatures from the intrinsic components of the interrogated system, which in biological matrices tend to be weak, inefficient scatterers and spectrally similar, [53] such that subtle differences must be discerned by the incorporation of chemometric methods. SERS unlike Raman is not reliant on native chromophores and a vast array of efficient scattering molecules, [54][55][56][57][58][59] with large Raman cross sections, can be conjugated to metallic scaffolds for the provision of distinct, optically strong, spectral signatures. By capitalising on this conferred enhancement, through the implementation of a metal surface and superior reporting moieties, the measured spectral intensities can be significantly enhanced.…”