Surface potential study of selective interaction of potassium ions with valinomycin in Langmuir-Blodgett films

Langmuir-Blodgett films composed of valinomycin bilayers and protective bilayers of barium salt of disuccinilated glycerol-dialkylglycerol tetraether, which have been produced from lipid extract of thermophilic archaeon Sulfolobus solfataricus, are deposited and studied by the surface potential technique. The formation of K+-valinomycin complexes after immersion of the samples in solutions containing potassium ions is proved. Interaction of valinomycin molecules with sodium ions is absent. The lower limit of the surface density of complexes formed in the film via selective interaction is evaluated. The efficiency of the system is at least 6%. The development of sensing elements for potassium ions on the basis of such films seems to be possible.