Sequence-specific control of azobenzene assemblies by molecular recognition of DNA

We investigated the molecular recognition between the amphiphile AzoAde, which is composed of azobenzene in the hydrophobic and adenine in the hydrophilic portion of the molecule, and oligonucleotides having a homogeneous base (dA(30), dT(30), dG(30), and dC(30)) at the air-water interface. On the basis of the complementary base-pairing of DNA in the duplex, orderly arrangement of AzoAde on templated dT(30) was examined using pi-A isotherm, UV-vis RAS, FT-IR RAS, and XPS measurements. Although there was little interaction between AzoAde and mismatched oligonucleotides (dA(30), dG(30) and dC(30)), AzoAde prepared on a dT(30) interacted with dT(30), subsequently forming a J-form assembly at the air-water interface. AFM observation of the LB films revealed the nanostructure of the J-formed AzoAde monolayer on the dT(30) subphase as well as the domain structures of the H-formed monolayers on the other oligonucleotide subphases. Therefore, dT(30) has a potential application as a template for assembling AzoAde at the air-water interface.