Probing Phospholipid Bilayer Structure and Interaction Using ATR-FTIR Spectroscopy.

The cell membrane plays a critical role in maintaining cellular integrity and regulating interactions between the cell and its environment. The understanding of many biological processes relies on obtaining molecular level information on the structure and dynamic behaviour of membranes, interactions between molecules within the membrane, as well as interactions between membrane and external compounds. Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy has emerged as a powerful analytical technique for investigating biological membranes due to its surface sensitivity and minimal sample preparation requirements. The technique enables the characterization of lipid bilayers, protein secondary structures, and membrane interactions with external molecules such as drugs or antimicrobial peptides. This mini-review summarizes the principles of ATR spectroscopy and highlights its applications in the study of lipid bilayers, including lipid organization, protein-lipid interactions, and membrane structural changes. The advantages, limitations, and future perspectives of ATR-based approaches in membrane research are also discussed.