Prospect of increasing secondary ion yields in ToF-SIMS using water cluster primary ion beams
Prospect of increasing secondary ion yields in ToF-SIMS using water cluster primary ion beams
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DOI：
10.1002/sia.5606
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发表时间：
2014-11-01
影响因子：
1.7
通讯作者：
Vickerman, J. C.
中科院分区：
文献类型：
--
作者：
Sheraz (nee Rabbani), S.;Barber, A.;Vickerman, J. C.
飞行时间二次离子质谱（ToF-SIMS）的低电离产率，特别是来自单细胞和组织的低电离产率被证明是允许该技术充分发挥其潜力的显著限制。通过质子介导的反应，包括将样品包埋在水中或在样品表面上喷水的许多方法已经显示出极大的前景，可以将电离产率提高10到100倍。基于这一假设，与Ionoptika Ltd合作开发了一种水团簇初级离子源，使用与氩团簇束类似的超声射流膨胀方法来产生巨大的水团簇离子（H2O）（n）（+）（n=1-10000）。用20 keV的（H_2O）（5000）（+），（H_2O）（3000）（+），Ar-3000（+）和C-60（+）初级离子束，在静态和高剂量条件下，测量了精氨酸、胆固醇、血管紧张素II和脂质混合物的离子产额。在1 × 10（11）ions/cm（2）离子剂量下，与C-60（+）相比，在水团簇撞击下观察到产率提高了约4倍，而在高离子剂量条件下，这增加了约10-50倍。版权所有（c）2014约翰威利父子有限公司
Low ionization yields in time of flight secondary ion mass spectrometry (ToF-SIMS) particularly from single cells and tissues are proving to be a significant limitation in allowing this technique to reach its full potential. A number of approaches including embedding the sample in water or spraying water above sample surface has shown great prospective for increasing the ionization yield by a factor of 10 to 100 through proton mediated' reaction. Based on this hypothesis, a water cluster primary ion source has been developed in collaboration with Ionoptika Ltd to generate giant water cluster ions (H2O)(n)(+) (n=1-10000) using a similar supersonic jet expansion methodology as for argon cluster beams. The ion yields of arginine, cholesterol, angiotensin II and a lipid mix have been measured under static and high ion dose conditions using (H2O)(5000)(+), (H2O)(3000)(+), Ar-3000(+) and C-60(+) primary ion beams at 20keV. An enhancement in yields up to a factor of around 4 is observed under water cluster impact, in comparison with C-60(+) at 1x10(11)ions/cm(2) ion dose, whereas this increases by around 10-50 times at high ion dose conditions. Copyright (c) 2014 John Wiley & Sons, Ltd.