In this project supported by the Chemical Measurement and Imaging Program, Researchers from the City College of New York, John Jay College of Criminal Justice, and the Metropolitan Museum of Art will develop methods for the evaluation of trace evidence and the examination of questioned documents by surface-enhanced Raman scattering. The focus is on pursuing non-destructive methods of analysis and techniques involving combination of Raman spectroscopy with other separation methods for the analysis of complex samples. This multidisciplinary collaboration seeks to achieve significant advances in the application of surface-enhanced Raman scattering (SERS) analysis to the evaluation of trace evidence and the examination of questioned documents. The project will continue to develop the core of a searchable spectral library of substances of forensic interest such as organic dyes and pigments, pharmaceuticals, and drugs of abuse. The involvement of undergraduate, Masters level, and PhD students in the research will also result in a substantial contribution to the training of the future generation of forensic scientists.
In this research, the investigators plan to focus on approaches for SERS analysis by developing standardized reproducible protocols for analysis of ink (including gel pen inks and black inks) and fiber samples, controlled substances, as well as colorants used in fabrics and paints. They will also develop procedures to deal with matrix interferences in SERS spectra, and continue to work on methods for completely non-destructive SERS analysis of documents and textiles, expanding the range of solvent systems and gel formulations to include easily available gelling materials such as agar and methylcellulose. The researchers will develop extraction procedures for gel pen and black inks suitable for SERS analysis and hyphenated techniques such as high performance thin-layer chromatography (HPTLC)-SERS for the separation and identification of mixtures.
