Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 363 (6426), 525-528

Identification of Site-Specific Isotopic Labels by Vibrational Spectroscopy in the Electron Microscope

Affiliations

Identification of Site-Specific Isotopic Labels by Vibrational Spectroscopy in the Electron Microscope

Jordan A Hachtel et al. Science.

Abstract

The identification of isotopic labels by conventional macroscopic techniques lacks spatial resolution and requires relatively large quantities of material for measurements. We recorded the vibrational spectra of an α amino acid, l-alanine, with damage-free "aloof" electron energy-loss spectroscopy in a scanning transmission electron microscope to directly resolve carbon-site-specific isotopic labels in real space with nanoscale spatial resolution. An isotopic red shift of 4.8 ± 0.4 milli-electron volts in C-O asymmetric stretching modes was observed for 13C-labeled l-alanine at the carboxylate carbon site, which was confirmed by macroscopic infrared spectroscopy and theoretical calculations. The accurate measurement of this shift opens the door to nondestructive, site-specific, spatially resolved identification of isotopically labeled molecules with the electron microscope.

Similar articles

See all similar articles

Cited by 1 PubMed Central articles

Publication types

LinkOut - more resources

Feedback