Non-Invasive Fourier Transform Infrared Microspectroscopy and Imaging Techniques: Basic Principles and Applications

The current paper describes rather new and straightforward non-invasive mid infrared spectroscopic techniques for the position sensitive identification of sample components. These techniques include mid infrared (MIR) microspectroscopy, mapping as well as imaging approaches e.g. in transmission, reflection-absorption, or attenuated total reflection mode. The basic principles of the different infrared microspectroscopy and imaging techniques are presented, with a critical evaluation of the technique compared to currently utilized other imaging techniques. The presented examples are focussed on applications in life science, e.g. exploration of the heterogeneity of a single sample, identification and biochemical characterisation of biological samples, ex-vivo monitoring the distribution of drugs in tissues. Additional applications are briefly discussed to illustrate the potentials and limitations of the presented techniques for medical diagnostics.