Journal
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
Volume 21, Issue 1, Pages 19-25Publisher
ROYAL SOC CHEMISTRY
DOI: 10.1039/b514401a
Keywords
-
Categories
Ask authors/readers for more resources
Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been established as a powerful surface analytical method for local elemental analysis on metallic.. ceramic, geological or biological sample surfaces. Here we show a new way of nanometre scale analysis of elements on sample surfaces by near-field LA-ICP-MS (NF-LA-ICP-MS). This technique uses the near-field enhancement effect on the tip of a thin silver needle in a laser beam (Nd:YAG laser, wavelength 532 nm) on the sample surface. The thin silver needle was etched electrolytically in an electrochemical cell using a droplet of citric acid as electrolyte. For nanolocal analysis by NF-LA-ICP-MS on soft matter (e.g., on 2-D gels and biological samples) a small volume transparent laser ablation chamber was constructed and coupled to a double-focusing sector field inductively coupled plasma mass spectrometer (ICP-MS). A small amount of soft sample material is ablated at atmospheric pressure by a single laser shot in the near-field of the silver tip in the defocused Nd:YAG laser beam. The ablated material is transported with argon as carrier gas into the inductively coupled plasma (ICP) ion source of the sensitive double-focusing sector field mass spectrometer with reverse Nier-Johnson geometry. By single-shot analysis on 2-D gels and biological surfaces doped with uranium in the mu g g(-1) range using NF-LA-ICP-MS all enhancement of ion intensities of transient signals in comparison with the background signal of up to factor 60 was observed. In gels doped with isotopically enriched Cu-65 and Zn-67 spikes by NF-LA-ICP-MS (single shot analysis) ion intensities up to the n x 10(5) cps range and isotope ratios (U-235/U-238, Cu-65/Cu-63 and Zn-67/Zn-64) were measured at a lateral resolution ill the nanometre scale. Using the near-field effect in LA-ICP-MS, it was demonstrated that nanolocal analysis is possible in single-shot measurements of elements oil biological samples and on a eel surface with spatial resolution at the hundreds of nanometres range. This first experiment on near-field LA-ICP-MS opens up a new, challenging path for future applications ill nanoimaging of elements in life science, biology and medicine, e.g., for analyses of single cells, cell organelles or biological structures at nanometre range in order to detect neurodegenerative diseases, but also in material science, nanotechnologies and nanoelectronics.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available