Studies of bilayers and vesicle adsorption to solid substrates: Development of a miniature streaming potential apparatus (SPA)

Younjin Min, Noshir Pesika, Joe Zasadzinski, Jacob Israelachvili

Research output: Contribution to journalArticlepeer-review

17 Scopus citations

Abstract

A new miniature streaming potential apparatus (SPA) was developed to determine the streaming potentials (Ψstr.) and zeta potentials (ζ) of substrates under different ionic conditions while simultaneously visualizing the state of the surfaces, such as the adsorption of surfactants or polymers, using fluorescence microscopy and/or fluorescence recovery after photobleaching (FRAP). Experimental results with different surfaces show that the new SPA provides streaming potential values (hence zeta potentials) that agree with results obtained using traditional electrokinetic analyzers. Using the new SPA, the formation of supported lipid bilayers (SLBs) on glass from fluorescently labeled, unilamellar (∼100 nm diameter), charge neutral dimyristoyl-sn-glycero-3-phosphocholine (DMPC) vesicles was studied in aqueous electrolyte solutions at different lipid concentrations. Simultaneous zeta potential measurements and fluorescence imaging for measuring diffusion coefficients by confocal microscopy enabled us to precisely monitor the changes in the surface charge as well as in the surface morphology during SLB formation from vesicles. For a fixed incubation time of 5 min, both results revealed that the adsorption of intact vesicles and/or discrete bilayer patches were observed below a threshold concentration, above which the formation of continuous SLBs occurred leading to an estimate for the ζ-potential and for the diffusion coefficient of -9.1 ± 1.6 mV and (1.1 ± 0.02) x 10-12 m2/s, respectively.

Original languageEnglish (US)
Pages (from-to)8684-8689
Number of pages6
JournalLangmuir
Volume26
Issue number11
DOIs
StatePublished - Jun 1 2010

Fingerprint Dive into the research topics of 'Studies of bilayers and vesicle adsorption to solid substrates: Development of a miniature streaming potential apparatus (SPA)'. Together they form a unique fingerprint.

Cite this