Advanced Raman Spectroscopic Methods for the Identification of Trace Evidence

在这个由化学测量和成像计划支持的项目中，来自纽约城市学院、约翰·杰伊刑事司法学院和大都会艺术博物馆的研究人员将开发通过表面增强拉曼散射评估痕量证据和检查可疑文件的方法。重点是追求非破坏性的分析方法和技术，包括拉曼光谱与其他分离方法的组合，用于复杂样品的分析。这一多学科合作旨在实现表面增强拉曼散射（Sers）分析应用于痕量证据评估和可疑文件检查的重大进展。该项目将继续开发一个可搜索的光谱库的核心，其中包括有机染料和颜料、药品和滥用药物等具有法医学意义的物质。本科生、硕士生和博士生的参与也将为培养下一代法医科学家做出实质性贡献。在这项研究中，研究人员计划通过开发标准化的可重复的墨水分析方案来专注于Sers分析方法。（包括中性笔墨水和黑色墨水）和纤维样品、受控物质以及用于织物和涂料的着色剂。他们还将开发处理Sers光谱中基质干扰的程序，并继续研究对文件和纺织品进行完全非破坏性Sers分析的方法，扩大溶剂系统和凝胶配方的范围，以包括易于获得的凝胶材料，如琼脂和甲基纤维素。研究人员将开发适用于Sers分析的中性笔和黑色墨水的提取程序，以及用于分离和鉴定混合物的高效薄层色谱（HPTLC）-Sers等联用技术。

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.