Structures of Biomolecular Ions in the Gas Phase Probed by Infrared Light Sources

Infrared (IR) spectroscopy of biomolecular ions combines mass spectrometry's high sensitivity and ability to analyze complex mixtures with the enhanced structural information available from vibrational spectroscopy. IR spectroscopy is in principle well placed to distinguish isomers and allow chemical classification of unknown molecules. This review gives an outline of current instrumentation, spectroscopic approaches, and potential bottlenecks. We discuss the most promising applications in bioanalytical mass spectrometry in view of recent experimental results, as well as future applications based on bioinformatics.