Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan.
Institute of Physics, Academia Sinica, Taipei 11529, Taiwan.
Analyst. 2021 May 4;146(9):2936-2944. doi: 10.1039/d0an02478c.
In this work, we report the development of a focused macromolecular ion beam with kinetic energy of up to 110 keV. The system consists of a quadrupole ion trap (QIT), einzel lens and linear accelerator (LINAC). Based on the combination of matrix-assisted laser desorption ionization (MALDI) and quadrupole ion trapping (QIT), ions were desorbed from the surface and trapped with an ion trap to form biomolecular ion packets. Positive- and negative-pulsed voltages were applied on each end-cap electrode of the QIT to extract the ion packets and form an ion beam that was subsequently focused via an einzel lens and accelerated by stepwise pulsed voltages. The tabletop instrument was designed and successfully demonstrated via measurements of molecular ions of insulin, cytochrome c and bovine serum albumin (BSA) with mass-to-charge ratios (m/z) ranging from ∼5.8 to 66.5 k. This is the first report of both a focused and high-kinetic-energy protein ion beam. In addition, both secondary ions and electrons were observed from the surface by hypervelocity ion beam bombardment. This focused macromolecular ion beam has demonstrated its potential in the study of interactions between large molecular ions with other molecules either in the gas phase or upon a surface.
在这项工作中，我们开发了一种能量高达 110keV 的聚焦大分子离子束。该系统由四极离子阱（QIT）、单透镜和直线加速器（LINAC）组成。基于基质辅助激光解吸电离（MALDI）和四极离子阱（QIT）的组合，离子从表面解吸并被离子阱捕获，形成生物分子离子包。正脉冲和负脉冲电压施加在 QIT 的每个端盖电极上，以提取离子包并形成离子束，然后通过单透镜聚焦，并通过逐步施加的脉冲电压加速。该台式仪器经过胰岛素、细胞色素 c 和牛血清白蛋白（BSA）的分子离子测量进行了设计和成功验证，其质荷比（m/z）范围为 5.8 至 66.5k。这是首次报道聚焦和高动能蛋白质离子束。此外，通过超高速离子束轰击还从表面观察到次级离子和电子。这种聚焦的大分子离子束已经证明了它在气相或表面上研究大分子量离子与其他分子之间相互作用的潜力。
