Voltammetric study on a condensed monolayer of a long alkyl cyclodextrin derivative as a channel mimetic sensing membrane

Abstract

For a fundamental study on the development of slgnal-ampWylng chemical sensors that mimic biological Ion channels, a control of membrane permeability based on the blocking of an Intramolecular channel by host-guest complexatlon has been Investigated for a condensed monolayer of a long alkyl derivative of /3-cyclodextrin having a channel-like structure (6

Reversal of charge selectivity in transmembrane protein pores by using noncovalent molecular adapters

“…In another study, a condensed monolayer of ␤CD with all seven 6-positions modified with long alkyl chains was deposited on a graphite electrode. The modified surface was permeable to the electroactive marker p-quinone (44). Transport through the central cavity was invoked because it could be blocked with guest molecules.…”

Factors Affecting Background Permeabilities of Ordered Mono-, Bi- and Multilayers as Channel Mimetic Sensing Membranes

“…The amounts (mole) of permeated marker obtained by graphical integration of the peak-shaped cyclic voltammograms are summarized in Table 2. The marker permeation increased with the hydrophobicity of markers: [Fe- The above results show that the leak of permeability markers through the uncharged t-OcCal [4]Et and tBuCal [6]Et membranes is markedly affected by the hydrophobicity and steric bulkiness of the markers used.…”

“…A monolayer of t-BuCal [6]Et or t-OcCal [4]Et was obtained by spreading a chloroform solution of the host on water (unbuffered). After the layer was allowed to stand for 20 min, the subphase was thermostated at a given temperature (5° C for valinomycin and crown ether systems and 20° C for calixarene systems).…”

“…For the depositions of mono-or multilayers, the surface was compressed up to a given surface pressure: 55 mN m ' for the lipid membranes without a host, 22 mN m ' for the valinomycin/didodecyl phosphate system, 20 mN m ' for the bis(12-crown-4)/ dioctadecyl phosphate system, l l mN m ' for the bis(15-crown-5)/didodecyl phosphate system and 25 mN m ' for t-BuCal [6]Et. The resultant monolayer was transferred at a rate of 2 mm min' onto a GC electrode by the horizontal lifting method.…”

“…The effects of hydrophobicity and bulkiness of three kinds of markers, i.e., [Fe(CN)6]4-, p-quinone and [Ru(bpy)3]2+, on the permeability through a t-OcCal [4]Et monolayer membrane at the air-water interface and through a t-BuCal [6]Et membrane transferred on a GC electrode by the LB method were examined by horizontal touch and conventional CV, respectively. The amounts (mole) of permeated marker obtained by graphical integration of the peak-shaped cyclic voltammograms are summarized in Table 2.…”