Infrared scanning near-field optical microscopy investigates order and clusters in model membranes

• Published in: Journal of microscopy (Oxford) Vol. 229; no. 2; pp. 259 - 263
• Main Authors: GENEROSI, J, MARGARITONDO, G, SANGHERA, J.S, AGGARWAL, I.D, TOLK, N.H, PISTON, D.W, CASTELLANO, A. CONGIU, CRICENTI, A
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.02.2008
• Subjects: Lipid bilayers; Lipid Bilayers - chemistry; Membrane Lipids - chemistry; membranes; Microscopy, Confocal - instrumentation; Microscopy, Confocal - methods; Models, Biological; Phosphatidylcholines - chemistry; scanning near-field optical microscopy; Spectrophotometry, Infrared - instrumentation; Spectrophotometry, Infrared - methods
• ISSN: 0022-2720; 1365-2818
• DOI: 10.1111/j.1365-2818.2008.01896.x

Due to its surface sensitivity and high spatial resolution, scanning near-field optical microscopy (SNOM) has a significant potential to study the lateral organization of membrane domains and clusters. Compared to other techniques, infrared near-field microscopy in the spectroscopic mode has the advantage to be sensitive to specific chemical bonds. In fact, spectroscopic SNOM in the infrared spectral range (IR-SNOM) reveals the chemical content of the sample with a lateral resolution around 100 nm ( Cricenti et al., 1998a, 1998b, 2003 ). Model lipid membranes were studied by IR-SNOM at several wavelengths. Topographical micrographs reveal the presence of islands at the surface and the optical images indicate the formation of locally ordered multiple bilayers - both critically important features for biotechnology and medical applications.