基于纳米材料的表面辅助激光解吸离子化质谱研究

Nanomaterial-Based Surface-Assisted Laser Desorption Ionization Mass Spectroscopy

基质辅助激光解吸离子化质谱(MALDI-MS)作为一种常规的分析表征方法主要用于生物大分子的分析,如蛋白质、多肽、多糖及核酸等。然而,MALDI-MS中使用的有机小分子基质在低分子量区会产生背景干扰,很难分析小分子量化合物(m/z<700)。最近,基于纳米材料的免有机基质的激光解吸离子化质谱(又称为表面辅助激光解吸离子化质谱,SALDI-MS)有效解决了上述问题。SALDI-MS分析中使用的起到能量转移作用的纳米材料在低分子量区间不会产生背景干扰峰,可以将分析对象由大分子扩展到小分子。另外,SALDI-MS还具有许多其他优点,如样品制备简单、信噪比高、耐盐性好、基底表面信号重复性好及可实现样品的定量分析等,显示了较好的应用前景。本文综述了研究较多的四大类纳米材料在SALDI-MS分析、检测及成像方面的应用,包括碳纳米材料(富勒烯、碳纳米管、石墨烯及氧化石墨烯)、硅纳米材料(多孔硅、硅纳米纤维、硅纳米粒子)、其他材料纳米粒子(包括金属纳米粒子、金属氧化物纳米粒子、无机盐纳米粒子及量子点等)及纳米杂化多孔材料,详细介绍了最近的一些研究进展;并讨论了纳米材料在SALDI-MS应用中的能量转移机理。最后,讨论了该领域未来的研究内容和方向以及亟待研究的重要问题。

Matrix-assisted laser desorption ionization mass spectroscopy （MALDI-MS） is a routine analytical characterization method, which was initially applied in the analysis of biological macromolecules, such as protein, polypeptide, polysaccharide and nucleic acid. However, MALDI-MS does not allow the sensitive detection of analytes in the low mass region （m/z 〈 700） because of strong background signals arising from the matrix. Recently, the organic matrix-free laser desorption ionization mass spectrometry based on nanomaterials （which is also known as surface-assisted laser desorption ionization mass spectrometry, SALDI-MS ） has effectively solved the above problem. With the use of nanomaterial-based MS technique, the detectable mass range of SALDI-MS has been extended from the low-mass region for the analysis of small molecules to the high-mass region for the analysis of large molecules. The nanomaterial-based MS technique transfers energy through the nanometer material with no interference peaks between the matrix and analyte in the low molecular weight. In addition, SALDI-MS also affords several advantages, such as simple sample preparation, high signal-to-noise ratio, high salt tolerance, the improved reproducibility of peak intensities and the possibility of quantitative analysis, showing good prospects. In this paper, we mainly describe and review in detail four types of nanomaterials developed for application in SALDI-MS detection and imaging that were reported in recent years, including carbon nanomaterials （fullerenes, carbon nanotubes, graphene and graphene oxide ）, silicon nanomaterials （porous silicon, silicon nanofiber, silica nanoparticles）, other nanoparticles （including metal nanoparticles, metal oxide nanoparticles, inorganic nanoparticles and quantum dots） and nanoporous materials. Besides, the energy transfer mechanism of nanomaterials in the application of SALDI-MS is discussed. Finally, the future research content and direction as well as the important problem to be studied are discussed.