[Host-guest molecular recognition involving membrane potential changes].

Studies on host-guest molecular recognition at membrane surfaces, which involves changes in the membrane potential, are described. A special focus was placed on basic approaches for the potentiometric discrimination of organic guests in liquid membrane systems. The following modes of host-guest interaction have been exploited for the structure discrimination based on membrane potential changes. (i) Electrostatic interaction by protonated polyamine hosts to discriminate organic anion guests. (ii) Complementary base pairing by hosts having a cytosine residue to discriminate nucleotide guests bearing guanine and adenine bases. (iii) Inclusion of nonpolar moieties of guests by a calix[6]arene hexaester or a beta-cyclodextrin derivative to discriminate amine guests having different steric structures. Some characteristic aspects of host-guest molecular recognition at membrane surfaces are discussed in comparison with those in homogeneous solutions.