Functionalization of quartz crystal microbalances with liposomes containing the N-hydroxysuccinimide ester of palmitic acid.

We developed a fast and simple method to functionalize a quartz crystal microbalance (QCM) with liposomes composed of phosphatidylcholine lipid and the N-hydroxysuccinimide (NHS) ester of palmitic acid. The liposome was applied directly to a bare gold surface of a QCM to prepare the lipid bilayer presenting NHS groups on the surface. The whole functionalization process was completed within 1 h using stored lipid films. Streptavidin immobilization efficiency of the method was comparable to the 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC)/NHS chemical method, and the activity of the biotinylated antibody immobilized through the streptavidin was stably retained in repeated surface regeneration with the dissociation buffer.