Weber Alexis, Amin Mohamed O, Ermolenkov Vladimir, Al-Hetlani Entesar, Lednev Igor K
Department of Chemistry, University at Albany, SUNY, 1400 Washington Avenue, Albany, New York 12222, United States.
Department of Chemistry, Kuwait University, Faculty of Science, P.O. Box 5969, 13060, Safat, Kuwait.
Anal Chem. 2025 Feb 25;97(7):3864-3871. doi: 10.1021/acs.analchem.4c04581. Epub 2025 Jan 30.
DNA phenotyping plays a central role in modern practical forensics, yet an overwhelming amount of evidence creates significant backlogs in all major crime laboratories. A fast nondestructive test of a potential biological stain prior to DNA phenotyping should reduce the number of irrelevant samples for the analysis and increase the efficiency of the overall process. Evidence items recovered from the crime scene can often include body fluid traces, such as oral fluid (OF). This proof-of-concept study demonstrates the effectiveness of Deep-UV Raman spectroscopy in identifying OF stains on substrates such as cotton, polyester, and blue denim, commonly encountered in forensic investigations. Through spectral interpretation and statistical analysis, this study compares Raman spectra from OF extracted from substrates with pure OF spectra. Additionally, comparative analysis with near-infrared (NIR) Raman spectroscopy to deep-UV Raman spectroscopy was performed. Distinct advantages of deep-UV Raman spectroscopy were determined, including reduced sample preparation requirements and the absence of fluorescence background, enhancement of the signal-to-noise ratio, and simplified data preprocessing. Using statistical analysis methods like principal component analysis and partial least-squares discriminate analysis, differentiation between OF and non-OF samples was possible. Overall, this study underscores the versatility and potential of deep-UV Raman spectroscopy as a valuable tool in forensic science.
DNA 表型分析在现代实际法医学中起着核心作用，但大量证据导致所有主要犯罪实验室都出现了严重的积压。在进行DNA表型分析之前，对潜在生物污渍进行快速无损检测应能减少用于分析的无关样本数量，并提高整个过程的效率。从犯罪现场回收的证据物品通常可能包括体液痕迹，如口腔液（OF）。这项概念验证研究证明了深紫外拉曼光谱法在识别法医调查中常见的诸如棉花、聚酯和蓝色牛仔布等基质上的OF污渍方面的有效性。通过光谱解释和统计分析，本研究将从基质中提取的OF的拉曼光谱与纯OF光谱进行了比较。此外，还进行了近红外（NIR）拉曼光谱与深紫外拉曼光谱的对比分析。确定了深紫外拉曼光谱的明显优势，包括降低样品制备要求、不存在荧光背景、提高信噪比以及简化数据预处理。使用主成分分析和偏最小二乘判别分析等统计分析方法，可以区分OF样本和非OF样本。总体而言，本研究强调了深紫外拉曼光谱作为法医学中一种有价值工具的多功能性和潜力。
