Sizing by Weighing: Characterizing Sizes of Ultrasmall-Sized Iron Oxide Nanocrystals Using MALDI-TOF Mass Spectrometry

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• 作者：Byung Hyo Kim ; Kwangsoo Shin ; Soon Gu Kwon ; Youngjin Jang ; Hyun-Seok Lee ; Hyunjae Lee ; Samuel Woojoo Jun ; Jisoo Lee ; Sang Yun Han ; Yong-Hyeon Yim ; Dae-Hyeong Kim ; Taeghwan Hyeon
• 刊名：The Journal of the American Chemical Society
• 出版年：2013
• 出版时间：February 20, 2013
• 年：2013
• 卷：135
• 期：7
• 页码：2407-2410
• 全文大小：368K
• 年卷期：v.135,no.7(February 20, 2013)
• ISSN：1520-5126

文摘

We present a rapid and reliable method for determining the sizes and size distributions of <5 nm-sized iron oxide nanocrystals (NCs) using matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (MS). MS data were readily converted to size information using a simple equation. The size distribution obtained from the mass spectrum is well-matched with the data from transmission electron microscopy, which requires long and tedious analysis work. The size distribution obtained from the mass spectrum is highly resolved and can detect size differences of only a few angstroms. We used this MS-based technique to investigate the formation of iron oxide NCs, which is not easy to monitor with other methods. From ex situ measurements, we observed the transition from molecular precursors to clusters and then finally to NCs.