One method to create planar lipid bilayers on solid substrates involves the transfer of lipids from liposomes to the support. We have varied the composition of liposomes systematically using factorial experimental designs and analyzed the adsorption behaviour of lipids from these liposomes onto solid supports. The hydrophilic supports were either used plain or modified with a monolayer of a lipid mixture, exposing hydrophobic groups. The monolayer-covered supports were used to identify factors important for adhesion and stability. Lipid adsorption kinetics was primarily studied on plain silicon supports in an ellipsometric cell or on a silicon nitride surface in a resonant mirror system (IAsys), using the systematic approach. Saturated phospholipids were essential for the required stability. Mixtures of dipalmitoylphosphatidylcholine, dipalmitoylphosphatidylglycerol, dipalmitoylphosphatidylethanolamine and cholesterol in combination with proteins were investigated in further detail as regards kinetics. The propensity to form a supported planar bilayer could be manipulated by the presence of calcium ions.
The portable detector ImmunoSMART was combined with the cyclone air sampler to detect the model bioagent E. coli DH5a in bioaerosols. The selected capture antibody was immobilized on gold electrodes, antibody-peroxidase conjugate served as a tracer. In buffer, the amperometric immunosensor measured 10 3 to 10 8 CFU/mL within 30 min. Detection in air was realized in a closed aerosol chamber. Automated dissemination of the cells, sampling and measurement allowed remote testing of the cyclone/immunodetector. The level of 150 CFU/L in air was clearly indicated (20 min analysis including 5 min sampling) and independently confirmed using the slit sampler and agar cultivation. The results seem promising for further extended tests in both aerosol chamber and field trial conditions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.