Matrix-assisted laser desorption/ionization (MALDI) mechanism revisited
Matrix-assisted laser desorption/ionization (MALDI) mechanism revisited
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DOI：
10.1016/j.aca.2006.08.062
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发表时间：
2007-01-16
影响因子：
6.2
通讯作者：
Chen, Chung Hsuan
中科院分区：
文献类型：
--
作者：
Chang, Wei Chao;Huang, Ling Chu Lora;Chen, Chung Hsuan
虽然基质辅助激光解吸电离（MALDI）技术发展至今已有十多年的历史，并已成功地应用于临床，但其详细的作用机制仍不清楚。两大模式;即光化学电离（PI）和团簇电离（CI）机制已被提出来解释许多实验结果。利用光化学电离模型，分析物离子被认为是由质子化或去质子化过程产生的，该过程涉及分析物分子与气相中的基质离子碰撞。在团簇电离模型下，带电粒子被基质分子以强的光吸收脱附。分析物离子随后通过基质从簇离子中去溶剂化而产生。尽管如此，许多观察仍然不能用这两个模型来解释。在这项工作中，我们认为伪质子转移过程中的结晶作为一个主要的机制，用于生产分析物离子在MALDI。我们提出了一个能量转移诱导反离子化（ETID）模型来解释观察到的等量的正离子和负离子产生的MALDI大生物分子。一些实验结果用于各种模型的比较。(c)2006 Elsevier B. V.保留所有权利。
Although matrix-assisted laser desorption/ionization (MALDI) was developed more than a decade ago and broad applications have been successfully demonstrated, detailed mechanism of MALDI is still not well understood. Two major models; namely photochemical ionization (PI) and cluster ionization (CI) mechanisms have been proposed to explain many of experimental results. With the photochemical ionization model, analyte ions are considered to be produced from a protonation or deprotonation process involving an analyte molecule colliding with a matrix ion in the gas phase. With the cluster ionization model, charged particles are desorbed with a strong photoabsorption by matrix molecules. Analyte ions are subsequently produced by desolvation of matrix from cluster ions. Nevertheless, many observations still cannot be explained by these two models. In this work, we consider a pseudo proton transfer process during crystallization as a primary mechanism for producing analyte ions in MALDI. We propose an energy transfer induced disproportionation (ETID) model to explain the observation of an equal amount of positive and negative ions produced in MALDI for large biomolecules. Some experimental results are used for comparisons of various models. (c) 2006 Elsevier B.V. All rights reserved.