Impedance analysis of valinomycin activity in nano-BLMs

摘要

Nano-black lipid membranes (nano-BLMs) were obtained by functionalization of highly ordered porousalumina substrates with an average pore diameter of 60 nm based on a self-assembled alkanethiol sub-monolayer followed by spreading of 1,2-diphytanoyl-sn-glycero-3-phosphocholine dissolved in n-decaneon the hydrophobic substrate. By means of impedance spectroscopy, we analyzed the influence of theself-assembled alkanethiol submonolayer on the electrical properties of the nano-BLMs as well as theirlong-term stability. We were able to stably integrate nano-BLMs into a flow through system, which allowedus to readily exchange buffer solutions several times and accounts for mass transport phenomena. Theionophore valinomycin was successfully inserted into nano-BLMs and its transport activity monitored asa function of different potassium and sodium ion concentrations reflecting the specificity of valinomycinfor potassium ions.