Surface plasmon microscopy measurements of lipid vesicle adsorption on a micropatterned self-assembled monolayer

This paper presents a novel method of measuring the adsorption of egg-phosp hatidylcholine (egg-PC) vesicles onto a micropatterned heterogeneous self-a ssembled monolayer (SAM). Microcontact printing (mu CP) was used to make an array of mercaptoethanol patches surrounded by an octadecanethiol (ODT) SA M. Surface plasmon microscopy (SPM) followed the change in the different pl asmon minima of the mercaptoethanol and ODT SAMs with respect to lipid adso rption time. Gray scale analysis (GSA) of the two domains showed clear diff erences in the kinetics of lipid adsorption, which were equated to a very d ifferent mechanism of lipid vesicle fusion on microcontact printed (mu CP) SAMs compared with homogeneous SAMs. Surface plasmon microscopy combined wi th GSA has allowed us to spatially deconvolute the adsorption of lipid on a patterned surface, giving a unique insight into the lipid adsorption proce ss. Conventional surface plasmon resonance measurements were made on the ho mogeneous SAM moieties in order to quantify the gray scale analysis in term s of adsorbed lipid thickness.