Testing Molecular Homogeneity at the Nanoscale with Massive Cluster Secondary Ion Mass Spectrometry

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• 作者：Michael J. Eller ; Stanislav V. Verkhoturov ; Emile A. Schweikert
• 刊名：Analytical Chemistry
• 出版年：2016
• 出版时间：August 2, 2016
• 年：2016
• 卷：88
• 期：15
• 页码：7639-7646
• 全文大小：699K
• 年卷期：0
• ISSN：1520-6882

文摘

This study deals with assessing the homogeneity of a mixture of ultrasmall nanoparticles differing only by their respective functionalization. While measuring the relative abundance of nanoparticles with specific functionalization is feasible with mass spectrometry, the determination of mixed or segregated moieties is beyond current capabilities. Our approach is based on SIMS with massive projectiles, specifically Au<sub class="stack">400sub><sup class="stack">+4sup>. A distinct feature of bombardment with Au<sub class="stack">400sub><sup class="stack">+4sup> is abundant emission of multiple secondary ions from one projectile impact. Their analysis allows for examination of coemitted and thus colocalized molecules within the emission area of a single impact (∼10–15 nm in diameter). It is possible to collect the mass spectrum from each projectile impact, which probes individual nanodomains, allowing for examination of molecular homogeneity at the nanoscale.