Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States.
Anal Chem. 2011 Nov 15;83(22):8448-53. doi: 10.1021/ac201481r. Epub 2011 Oct 18.
In the present work, the advantages of a new, 100 kV platform equipped with a massive gold cluster source for the analysis of native biological surfaces are shown. Inspection of the molecular ion emission as a function of projectile size demonstrates a secondary ion yield increase of ~100× for 520 keV Au(400)(4+) as compared to 130 keV Au(3)(1+) and 43 keV C(60). In particular, yields of tens of percent of molecular ions per projectile impact for the most abundant components can be observed with the 520 keV Au(400)(4+) probe. A comparison between 520 keV Au(400)(4+) time-of-flight-secondary ion mass spectrometry (TOF-SIMS) and matrix assisted laser desorption ionization-mass spectrometry (MALDI-MS) data showed a similar pattern and similar relative intensities of lipid components across a rat brain sagittal section. The abundant secondary ion yield of analyte-specific ions makes 520 keV Au(400)(4+) projectiles an attractive probe for submicrometer molecular mapping of native surfaces.
在本工作中，展示了一种新的 100 kV 平台的优势，该平台配备了大量的金团簇源，可用于分析天然生物表面。检查作为射弹尺寸函数的分子离子发射，与 130 keV 的 Au(3)(1+)和 43 keV 的 C(60)相比，520 keV 的 Au(400)(4+)的二次离子产率增加了约 100×。特别是，用 520 keV 的 Au(400)(4+)探针可以观察到最丰富的成分的每个射弹撞击产生的数十个分子离子的产率。520 keV 的 Au(400)(4+)飞行时间二次离子质谱（TOF-SIMS）和基质辅助激光解吸电离质谱（MALDI-MS）数据之间的比较显示了大鼠脑矢状切片上脂质成分的相似模式和相似的相对强度。分析物特异性离子的丰富二次离子产率使得 520 keV 的 Au(400)(4+)射弹成为用于天然表面的亚微米分子映射的有吸引力的探针。
