Model multilayer structures for three-dimensional cell imaging

doi:10.1016/j.apsusc.2006.02.209

2006-07-01

PRE

Christopher Szakal

Michael E. Kurczy

Nicholas Winograd *

DOI：10.1016/j.apsusc.2006.02.209

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摘要

En 中文

The prospects for SIMS three-dimensional analysis of biological materials were explored using model multilayer structures. The samples were analyzed in a TbF-SIMS spectrometer equipped with a 20 keV buckminsterfullerene (C-60(+)) ion source. Molecular depth information was acquired using a C-60(+) ion beam to etch through the multilayer structures at specified time intervals. Subsequent to each individual erosion cycle, static SIMS spectra were recorded using a pulsed C-60(+) ion probe. Molecular intensities in sequential mass spectra were monitored as a function of primary ion fluence. The resulting depth information was used to characterize C-60(+) bombardment of biological materials. Specifically, molecular depth profile ;studies involving dehydrated dipalmitoyl-phosphatidylcholine (DPPC) organic films indicate that cell membrane lipid materials do not experience significant chemical damage when bombarded with C-60(+) ion fluences greater than 10(15) ions/cm(2). Moreover, depth profile analyses of DPPC- sucrose frozen multilayer structures suggest that biomolecule information can be uncovered after the C-60(+) sputter removal of a 20 nm overlayer with no appreciable loss of underlying molecular signal. The experimental results support the potential for three-dimensional molecular mapping of biological materials using cluster SIMS. (c) 2006 Elsevier B.V. All rights reserved.

Keyword:

ToF-SIMS

polyatomic projectile

C-60(+)

molecular depth profiling

3D imaging