Related Experiment Video
Updated: Mar 26, 2026

Fluorescence Recovery after Merging a Droplet to Measure the Two-dimensional Diffusion of a Phospholipid Monolayer
Published on: October 15, 2015
Diffusional motion as a gauge of fluidity and interfacial adhesion. Supported alkylphosphonate monolayers
S M Baumler1, Thomas M Reidy1, G J Blanchard1
1Michigan State University, Department of Chemistry, 578 S. Shaw Lane, East Lansing, MI 48824, USA.
Abstract:
We report on the use of diffusion measurements to gauge the fluidity and surface binding properties of a molecular monolayer. The monolayer film consists of octadecyl-1-phosphonic acid (ODPA) and controlled amounts of a lyso-phosphatidic acid tagged with the fluorescent probe BODIPY (BLPA). The monolayer films were formed using a Langmuir-Blodgett (LB) trough and deposited onto a glass slide. Monolayer morphology was characterized during film formation using Brewster angle microscopy (BAM). Fluorescence Recovery After Photobleaching (FRAP) microscopy was used to measure translational diffusion of BLPA and Fluorescence Anisotropy Decay Imaging (FADI) was used to measure rotational diffusion of the BLPA chromophore. These results provide information on the motional freedom of the probe and, importantly, on the strength of interaction between the probe and the support. Compositional variations in the monolayer give rise to changes in constituent dynamics that reflect intermolecular interactions.
Related Concept Videos
Membrane Fluidity
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is...
Membrane Fluidity
Protein Diffusion in the Membrane
Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model
Surface Tension of Fluid
Surface tension varies...
Fluid Mosaic Model

