**Introduction to Infrared Spectroscopy in Life and Biomedical Sciences**

Theophile Theophanides

*National Technical University of Athens, Chemical Engineering Department, Radiation Chemistry and Biospectroscopy, Zografou Campus, Zografou, Athens Greece* 

#### **1. Introduction**

By 1950 IR spectroscopy was applied to more complicated molecules such as proteins by Elliot and Ambrose [1]. The studies showed that IR spectroscopy could also be used to study complex biological molecules, such as proteins, DNA and membranes and thus, IR could be also used as a powerful tool in biosciences [2, 3].

The FT-IR spectra of very complex biological or biomedical systems, such as, atheromatic plaques and carotids were studied and characterized as it will be shown in chapters of this book. From the interpretation of the spectra and the chemistry insights very interesting and significant conclusions could be reached on the healthy state of these systems. It is found that FT-IR can be used for diagnostic purposes for several diseases. Characteristic absorption bands of proteins, amide bands, O-P-O vibrations of DNA or phospholipids, disulfide groups, e.t.c. can be very significant and give new information on the state of these molecules.

Furthermore, with the addition of micro-FT-IR spectrometers one can obtain IR spectra of tissue cells, blood samples, bones and cancerous breast tissues [4-7]. Samples in solution can also be measured accurately. The spectra of substances can be compared with a store of thousands of reference spectra. IR spectroscopy is useful for identifying and characterizing substances and confirming their identity since the IR spectrum is the "fingerprint" of a substance.

Therefore, IR has also a forensic purpose and is used to analyze substances, such as, alcohol, drugs, fibers, hair, blood and paints [8-12].In the sections that are given in the book the reader will find numerous examples of such applications.

#### **2. References**


**Section 1** 

**Brain Activity and Clinical Research** 

