Wetting films of lipids in the development of sensitive interfaces. An electrochemical approach

The potential of manganese in construction of electrodes modified with thin liquid films of lipids

“…Although the phosphate group is shown to be the main site of ion binding [30][31][32][33][34], some new EPR studies [35] show that, due to transient water-filled defects within the lipid layer, Mn 2þ diffuses even deeper into the acyl chain region. Thus it is not strange that, unlike species which are incapable of penetrating the film (e.g., ascorbate, Fe(CN) 3À=4À 6 , iodide I À [16][17][18][19][20]), manganese oxidation by the GCE is not hampered and can be used for mediation of redox reactions in the surrounding electrolyte. Furthermore, the above impedance data reveal an improvement of the dielectric properties of the film under the influence of divalent cations.…”

“…The arrangement of this interface required a sufficient period of time in which the two liquids were in contact, hence allowing a reliable value of the lipid surface concentration and the development of an adsorbed monolayer to be achieved. Such conditions could be achieved by an appropriate choice of the bulk lipid concentration and incubation of the system [17]. This turned out to be a prerequisite for the generation of a stable film.…”

“…As described earlier [16,17], the preparation technique of the films was based on a gradual approach of the working GCE to a preformed liquidjliquid interface between the electrolyte and the forming solution of lipid. The arrangement of this interface required a sufficient period of time in which the two liquids were in contact, hence allowing a reliable value of the lipid surface concentration and the development of an adsorbed monolayer to be achieved.…”

“…Depending on the conditions of wetting (the kind of substrate, lipid solution, applied potential, etc.) films with different thicknesses could be obtained in this way [15][16][17]. These films feature the durability of the supported layers, but possess higher fluidity.…”

Membrane surface functionalization via theophylline derivative coating and streptavidin immobilization

“…The modification of solid substrates, including membranes, using bioactive materials is an attractive field of research for developing new devices such as biosensors, structured multilayers or controlled-release delivery systems [1][2][3]. Membrane grafting, atomic layer deposition, photolithography and deep coating are typical surface modification techniques depending on membrane materials and specific applications [4][5][6][7].…”