Barros R M, Clemente M C H, Martins G A V, Silva L P
Embrapa Recursos Genéticos e Biotecnologia, Laboratório de Nanobiotecnologia (LNANO), Brasília 70770-917, DF, Brazil; Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-graduação em Nanociência e Nanobiotecnologia, Brasília 70910-900, DF, Brazil; Identification Institute, Civil Police of the Federal District, SAI Sudoeste, Bloco A - Ed. Sede, Brasilia 70610-200, DF, Brazil.
Universidade de Brasília, Instituto de Química, Laboratório de Catálise, Brasília 70904-970, DF, Brazil.
Sci Justice. 2018 Jul;58(4):264-270. doi: 10.1016/j.scijus.2018.03.005. Epub 2018 Mar 26.
Recent advances in nanotechnology applied in forensic sciences have contributed to consider new approaches including chemical evaluation of latent fingermarks. Significant improvement to the detection of small organic molecules has been reached with matrix-free methods associated to laser desorption/ionization mass spectrometry. The present study investigated the application of mesocellular siliceous foam (MCF) as an ionizing agent for laser desorption/ionization (LDI-MS) analysis of fingermarks as a proof of concept research. Fingermarks from three different donors were deposited directly onto a MALDI target plate and α-CHCA matrix solution, MCF ethanolic suspension or MCF/magnetic powder mixture were used for treatment. Microscopy characterization of MCF support showed particles with irregular morphology and variable sizes, and a unordered porous surface with pores diameter ranging from about 10 to 20 nm. Results showed less intense peaks in the spectra produced by the MCF support (control). Analysis of fingermarks showed ions related to endogenous and exogenous molecular components, including possible lipids from human sebum and quaternary ammonium cations commonly present in cosmetics. Promising and reproducible results were obtained for the fingermarks dusted with the MCF/magnetic powder mixture. Considering the forensic applications of nanomaterials for the analysis of small molecules in biological samples by matrix-free LDI techniques, the advantages of silica based materials should be further investigated.
纳米技术在法医学中的最新进展促使人们考虑采用新方法，包括对潜在指纹进行化学评估。与激光解吸/电离质谱联用的无基质方法已使小分子检测有了显著改进。本研究以概念验证研究的方式，探究了介孔硅泡沫（MCF）作为指纹激光解吸/电离（LDI-MS）分析的电离剂的应用。将来自三名不同捐赠者的指纹直接沉积在MALDI靶板上，并使用α-CHCA基质溶液、MCF乙醇悬浮液或MCF/磁粉混合物进行处理。MCF载体的显微镜表征显示，颗粒形态不规则、大小各异，且表面具有无序多孔结构，孔径约为10至20纳米。结果表明，MCF载体（对照）产生的光谱中的峰强度较低。指纹分析显示出与内源性和外源性分子成分相关的离子，包括可能来自人皮脂的脂质以及化妆品中常见的季铵阳离子。用MCF/磁粉混合物处理的指纹获得了有前景且可重复的结果。考虑到纳米材料通过无基质LDI技术在生物样品小分子分析中的法医学应用，应进一步研究硅基材料的优势。
