Phonon-Assisted Field Emission in Silicon Nanomembranes for Time-of-Flight Mass Spectrometry of Proteins

详细信息    查看全文

• 作者：Jonghoo Park ; Zlatan Aksamija ; Hyun-Cheol Shin ; Hyunseok Kim ; Robert H. Blick
• 刊名：Nano Letters
• 出版年：2013
• 出版时间：June 12, 2013
• 年：2013
• 卷：13
• 期：6
• 页码：2698-2703
• 全文大小：352K
• 年卷期：v.13,no.6(June 12, 2013)
• ISSN：1530-6992

文摘

Time-of-flight (TOF) mass spectrometry has been considered as the method of choice for mass analysis of large intact biomolecules, which are ionized in low charge states by matrix-assisted-laser-desorption/ionization (MALDI). However, it remains predominantly restricted to the mass analysis of biomolecules with a mass below about 50鈥?00 Da. This limitation mainly stems from the fact that the sensitivity of the standard detectors decreases with increasing ion mass. We describe here a new principle for ion detection in TOF mass spectrometry, which is based upon suspended silicon nanomembranes. Impinging ion packets on one side of the suspended silicon nanomembrane generate nonequilibrium phonons, which propagate quasi-diffusively and deliver thermal energy to electrons within the silicon nanomembrane. This enhances electron emission from the nanomembrane surface with an electric field applied to it. The nonequilibrium phonon-assisted field emission in the suspended nanomembrane connected to an effective cooling of the nanomembrane via field emission allows mass analysis of megadalton ions with high mass resolution at room temperature. The high resolution of the detector will give better insight into high mass proteins and their functions.

Keywords:

NEMS; nanomembrane; phonons; mass spectrometry