Univ. Montpellier, CNRS, ENSCM, IBMM, UMR 5247, Montpellier, France.
Bioresources Department, National Institute for Research and Development in Chemistry and Petrochemistry, Bucharest, Romania.
Rapid Commun Mass Spectrom. 2023 Apr 30;37(8):e9476. doi: 10.1002/rcm.9476.
Surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) is an approach derived from matrix-assisted laser desorption/ionization (MALDI)-MS which overcomes the drawbacks associated with the use of organic matrices required to co-crystallize with the analytes. Indeed, nanomaterials commonly used in SALDI-MS as inert surfaces to promote desorption/ionization (D/I) ensure straightforward direct deposition of samples while providing mass spectra with ions only related to the compound of interest. The objective of this study was to develop a novel SALDI-MS approach based on steel plates that are surfaces very rapidly and easily tuned to perform the most efficient peptide detection as possible. To compare the SALDI efficacy of such metal substrates, D/I efficiency and deposit homogeneity were evaluated according to steel plate fabrication processes.
The studied surfaces were nanostructured steel plates that were chemically modified by perfluorosilane and textured according to different frequencies and laser writing powers. The capacity of each tested 100 surfaces was demonstrated by comparative analyses of a mixture of standard peptides (m/z 600-3000) performed with a MALDI-TOF instrument enabling MALDI, SALDI and imaging experiments.
A peptide mix was used to screen the different surfaces depending on their D/I efficiency and their ability to ensure homogeneous deposit of the samples. For that purpose, deposition homogeneity was visualized owing to reconstructed ionic images from all protonated or sodiated ions of the 10 peptides constituting the standard mix.
Seven surfaces were then selected satisfying the required D/I efficiency and deposit homogeneity criteria. Results obtained with these optimal surfaces were then compared with those recorded by MALDI-MS analyses used as references.
表面辅助激光解吸/电离质谱（SALDI-MS）是一种源自基质辅助激光解吸/电离（MALDI-MS）的方法，它克服了与使用共结晶分析物所需的有机基质相关的缺点。实际上，SALDI-MS 中常用的纳米材料作为惰性表面来促进解吸/电离（D/I），确保了样品的直接简单沉积，同时提供了仅与感兴趣化合物相关的离子的质谱。本研究的目的是开发一种基于钢板的新型 SALDI-MS 方法，该方法可以快速且轻松地调节钢板表面，以尽可能高效地检测肽。为了比较这些金属基底的 SALDI 效果，根据钢板制造工艺评估了 D/I 效率和沉积均匀性。
研究的表面是经过化学修饰的纳米结构化钢板，用全氟硅烷进行修饰，并根据不同的频率和激光写入功率进行纹理化。通过 MALDI-TOF 仪器对标准肽混合物（m/z 600-3000）进行比较分析，对每个测试的 100 个表面的能力进行了证明，这些实验可以进行 MALDI、SALDI 和成像实验。
使用肽混合物根据其 D/I 效率和确保样品均匀沉积的能力来筛选不同的表面。为此，通过重构来自构成标准混合物的 10 种肽的所有质子化或钠化离子的离子图像来可视化沉积均匀性。
然后选择了满足所需 D/I 效率和沉积均匀性标准的七个表面。然后将从这些最佳表面获得的结果与用作参考的 MALDI-MS 分析记录的结果进行比较。
