A Structural Mass Spectrometry Strategy for the Relative Quantitation of Ligands on Mixed Monolayer-Protected Gold Nanoparticles

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• 作者：Kellen M. Harkness ; Brian C. Hixson ; Larissa S. Fenn ; Brian N. Turner ; Amanda C. Rape ; Carrie A. Simpson ; Brian J. Huffman ; Tracy C. Okoli ; John A. McLean ; David E. Cliffel
• 刊名：Analytical Chemistry
• 出版年：2010
• 出版时间：November 15, 2010
• 年：2010
• 卷：82
• 期：22
• 页码：9268-9274
• 全文大小：298K
• 年卷期：v.82,no.22(November 15, 2010)
• ISSN：1520-6882

文摘

It is becoming increasingly common to use gold nanoparticles (AuNPs) protected by a heterogeneous mixture of thiolate ligands, but many ligand mixtures on AuNPs cannot be properly characterized due to the inherent limitations of commonly used spectroscopic techniques. Using ion mobility−mass spectrometry (IM-MS), we have developed a strategy that allows measurement of the relative quantity of ligands on AuNP surfaces. This strategy is used for the characterization of three samples of mixed-ligand AuNPs: tiopronin:glutathione (av diameter 2.5 nm), octanethiol:decanethiol (av diameter 3.6 nm), and tiopronin:11-mercaptoundecyl(poly ethylene glycol) (av diameter 2.5 nm). For validation purposes, the results obtained for tiopronin:glutathione AuNPs were compared to parallel measurements using nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) without ion mobility separation. Relative quantitation measurements for NMR and IM-MS were in excellent agreement, with an average difference of less than 1% relative abundance. IM-MS and MS without ion mobility separation were not comparable, due to a lack of ion signals for MS. The other two mixed-ligand AuNPs provide examples of measurements that cannot be performed using NMR spectroscopy.