Improvement of biological time-of-flight-secondary ion mass spectrometry imaging with a bismuth cluster ion source
Improvement of biological time-of-flight-secondary ion mass spectrometry imaging with a bismuth cluster ion source
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DOI：
10.1016/j.jasms.2005.06.005
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发表时间：
2005-10-01
影响因子：
3.2
通讯作者：
Laprévote, O
中科院分区：
文献类型：
--
作者：
Touboul, D;Kollmer, F;Laprévote, O
在飞行时间二次离子质谱仪（TOF-SIMS）上安装了一种新型填充铋的液态金属离子枪（LMIG）。该光源提供了n = 1-7和q = 1和2的Biq(n)（q+）簇光束。合适的团簇比最近在TOF-SIMS成像中使用的Au-3（+）金团簇具有更好的强度和效率，并且具有更好的横向和质量分辨率。这种离子源发出的不同光束已被用于大鼠脑切片的生物成像测试。结果表明，在可及的质量范围和有用的横向分辨率方面，成像能力有了很大的提高。二次离子产率Y，消失横截面sigma，效率E = Y/sigma和有用的横向分辨率Delta L已经被比较了，使用不同的铋团簇，直接在大鼠脑切片表面上，以及几个正负二次离子，m/z范围从23到超过750。通过考虑一次离子电流的合理采集时间，比较了不同一次离子的效率和成像能力。其中，Bi-3（+）和Bi-2（+）离子的电流是Au-3（+）的5倍以上，是一种适合大面积成像的离子束。Bi-5（2+）离子具有大的二次离子产率和合理的强度，使其适合于小面积图像，具有优异的灵敏度和可能有用的横向分辨率< 400nm。
A new liquid metal ion gun (LMIG) filled with bismuth has been fitted to a time-of-flight-secondary ion mass spectrometer (TOF-SIMS). This source provides beams of Biq(n)(q+) clusters with n = 1-7 and q = 1 and 2. The appropriate clusters have much better intensities and efficiencies than the Au-3(+) gold clusters recently used in TOF-SIMS imaging, and allow better lateral and mass resolution. The different beams delivered by this ion source have been tested for biological imaging of rat brain sections. The results show a great improvement of the imaging capabilities in terms of accessible mass range and useful lateral resolution. Secondary ion yields Y, disappearance cross sections sigma, efficiencies E = Y/sigma, and useful lateral resolutions Delta L have been compared using the different bismuth clusters, directly onto the surface of rat brain sections and for several positive and negative secondary ions with m/z ranging from 23 up to more than 750. The efficiency and the imaging capabilities of the different primary ions are compared by taking into account the primary ion current for reasonable acquisition times. The two best e Bi-3(+) and Bi-2(+) The Bi-3(+) primary ions are ion beam has a current at least five times larger than Au-3(+) and therefore is an excellent beam for large-area imaging. Bi-5(2+) ions exhibit large secondary ions yields and a reasonable intensity making them suitable for small-area images with an excellent sensitivity and a possible useful lateral resolution < 400nm.