Applied Spectroscopy December Highlights
This issue’s Focal Point article reviews a powerful new capability which enables the chemical characterization of polymeric and biological samples at nanoscale spatial resolutions via infrared (IR) spectroscopy. The combination of a broadly tunable IR laser source with photothermal detection via the tip of an atomic force microscope (AFM) permits the collection of sub-diffraction-limited IR spectra with band contours identical to those obtained by conventional transmission IR spectroscopy.
The cover images show how the AFM-IRtechnique is used to acquire IR absorption spectra and absorption imageswith spatial resolution on the 50-100 nm scale, including the mapping of an IR-absorbing species in a single bacterium cell and the ability to differentiate the chemical composition of individual polymeric domains in a model pharmaceutical formulation.
Finally, it is shown that by controlling the polarization of the IR excitation laser, it is possible to obtain important information regarding themolecular orientation in electrospun nanofibers. For more information, please see the Focal Point article ‘‘AFM-IR: Combining Atomic Force Microscopy and Infrared Spectroscopy for Nanoscale Chemical Characterization’’, by Alexandre Dazzi, Craig B. Prater, Qichi Hu, D. Bruce Chase, John F. Rabolt, and Curtis Marcott.
See Applied Spectroscopy, Volume 66, Number 12 (2012) for a full list of articles.