利用光谱和质谱成像技术实现指纹痕量检测

Application of hyperspectral imaging and mass spectrometry imaging technique to fingerprint visualization and trace analysis

近年来,依赖于先进光源的化学成像技术迅速发展,极大提高了痕量检测的准确性,在公共安全、环境、食品、医药、考古等领域具有重要的实用价值.在痕量检测中,通过将成像技术与光谱测量技术、质谱技术等相结合,能够同时获取检验对象的物质组成和二维图像信息,不仅可以揭示材料表面的痕量物质成分及其分布,还可以在提高检验灵敏度的情况下,减少甚至避免传统检测手段所需要的特殊显现剂,因此与其他检验方法具有良好的兼容性.本文以指纹检验这一典型的痕量检测问题为例,阐述基于光谱和质谱成像技术的化学成像方法在痕量检测领域中的应用,从定向针对特定组分的化学成像和非定向的直接化学成像两个方面,综述了在指纹显现或显现增强中获得应用的主要成像手段,包括可见-近红外成像、红外成像、拉曼成像、质谱成像等.

Developing on advanced light sources, especially those applied in the areas of spectral imaging and mass spectrometry imaging, has made the trace analysis feasible and more reliable. These techniques show great potentials in various fields including forensic science, environment, food, pharmaceuticals, archaeology, etc. In many cases of trace analysis, it is expected to obtain both the spatial distributions and chemical compositions of the target objects. Through the combination of imaging technology with optical spectroscopy and mass spectrometry, it is possible to detect the trace chemicals on the surface of various materials as well as their spatial distributions, thus improving the accuracy of detection and the range of application. Moreover, trace analysis based on such methods can reduce or even avoid the use of special chemical reagents, and is compatible with the traditional chemical detection methods. In the paper, we focus on fingerprint visualization and analysis,as a typical trace analysis issue, to discuss the recent progress of the applicable chemical imaging technologies based on the advanced light sources. The effect of latent fingerprint development depends on not only features of fingerprint carrying object, but also the characteristics of fingerprint residues. In this paper, we provide an overview of two technical approaches: specific component targeted chemical imaging and nondirective chemical imaging. We describe the major technologies involved in this field, including visible-near infrared chemical imaging, mid-infrared chemical imaging, Raman imaging, and mass spectrometry imaging.