Lin Jieru, Zhang Chenjie, Xu Minmin, Yuan Yaxian, Yao Jianlin
College of Chemistry, Chemical Engineering and Materials Science, Soochow University Suzhou 215123 China
RSC Adv. 2018 Jul 6;8(43):24477-24484. doi: 10.1039/c8ra03808b. eCollection 2018 Jul 2.
The visualization and acquisition of information on substances within fingerprints have attracted considerable interest owing to their practical application in forensic science. There are still some challenges in the transfer and imaging of fingerprints and the extraction of residues. Here, a facile approach was successfully developed for transferring and recovering the pattern of fingerprints, which is based on surface-enhanced Raman spectroscopy (SERS) and an adhesive Au nanofilm (ANF). The reproducibility of SERS effects and the adhesive quality of the ANF enabled the transfer, recovery of the pattern and extraction of chemical residues from living/latent fingerprints. The results demonstrated that the pattern of living fingerprints, including ridges, furrows and sweat pores, was recovered on the basis of SERS mapping of the vibrational band of amino acids from endogenous protein substances. The dye rhodamine 6G (R6G) was employed as a developing agent to enhance the visualization of fingerprints by SERS mapping of the band at 1360 cm. Moreover, exogenous residues, such as cotinine (COT) and methylene blue (MB), were also detected by SERS. Their distribution in fingerprints was also determined, although it was not associated with the pattern of fingerprints. This indicated that the extraction process based on the adhesive ANF could be applied to transfer fingerprints from a crime scene to the laboratory for precise identification structural information on chemical residues and the pattern image of fingerprints. It is anticipated that the adhesive ANF when combined with an ultrahigh-sensitivity SERS technique could be developed as a promising tool for the visualization of fingerprints and monitoring of trace chemical residues for crime tracking in forensic science.
由于指纹中物质信息的可视化和获取在法医学中的实际应用，已引起了相当大的关注。在指纹的转移、成像以及残留物的提取方面仍存在一些挑战。在此，基于表面增强拉曼光谱（SERS）和粘性金纳米膜（ANF），成功开发了一种简便的方法来转移和恢复指纹图案。SERS效应的可重复性和ANF的粘性使得能够从活体/潜在指纹中转移、恢复图案并提取化学残留物。结果表明，基于内源性蛋白质物质中氨基酸振动带的SERS映射，恢复了活体指纹的图案，包括纹路、沟壑和汗孔。罗丹明6G（R6G）染料被用作显影剂，通过在1360 cm处的谱带的SERS映射来增强指纹的可视化。此外，还通过SERS检测到了可替宁（COT）和亚甲蓝（MB）等外源性残留物。尽管它们在指纹中的分布与指纹图案无关，但也对其进行了测定。这表明基于粘性ANF的提取过程可应用于将犯罪现场的指纹转移到实验室，以精确识别化学残留物的结构信息和指纹的图案图像。预计粘性ANF与超高灵敏度SERS技术相结合，有望成为法医学中用于指纹可视化和痕量化学残留物监测以追踪犯罪的工具。
