Analysis of Biological Structures by Electron Energy Loss Spectroscopy and Imaging

Autor: S. B. Andrews, R. D. Leapman
Rok vydání: 2001
Předmět:
Zdroj: Microscopy and Microanalysis. 7:1166-1167
ISSN: 1435-8115
1431-9276
DOI: 10.1017/s1431927600031901
Popis: As techniques for electron energy-loss spectroscopy (EELS) reach a higher degree of optimization, detection limits for analyzing biological structures are approaching those predicted by theory. in favorable specimens, single atom detection is predicted for elemental maps acquired by means of the scanning transmission electron microscope (STEM) equipped with a field emission source, paralleldetection EELS and a spectrum-imaging system. to obtain such results, the electron detector should have a detective quantum efficiency close to unity and a well behaved point-spread function; such design features are now available with a cooled charge-couple device (CCD) array. The energy-filtering transmission electron microscope (EFTEM) provides a complementary approach to mapping elements occurring at higher concentrations but distributed over larger regions of the specimen. Use of an optimized CCD detector in the EFTEM now enables accurate quantitation in addition to high analytical sensitivity, albeit not at the single atom level.
Databáze: OpenAIRE