title: Liponucleoside thin films: the special behaviour of guanosine.
abstract: We performed a comparative study of self-assembling properties of liponucleoside materials containing different nucleobases in their hydrophilic headgroups, but possessing the same type of lipophilic moiety in their hydrophobic tails. Surface pressure versus area isotherms (π(A)) of monolayers formed at the air-water interface show that guanine-based materials form stable monolayer films exhibiting a profound first order phase transition from the liquid expanded to the condensed phase. Materials based on other nucleobases form less stable films exhibiting a liquid-like behaviour. Analysis of surface structures of Langmuir films with Brewster angle microscopy (BAM) and of Langmuir-Blodgett (LB) films deposited on mica surface by atomic force microscopy (AFM) confirms surface organization as resolved from the isotherms. The specific behaviour of molecules with a guanine head group is attributed to their optimal hydrophilic/hydrophobic balance, which is associated with the low water solubility of guanine derivatives.
authors.affiliation: Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, SI-1000 Ljubljana, Slovenia. lucija.coga@fmf.uni-lj.si
authors.forename: Lucija
authors.initials: L
authors.lastname: Čoga
authors.forename: Tina
authors.initials: T
authors.lastname: Ilc
authors.forename: Miha
authors.initials: M
authors.lastname: Devetak
authors.forename: Stefano
authors.initials: S
authors.lastname: Masiero
authors.forename: Lucia
authors.initials: L
authors.lastname: Gramigna
authors.forename: Gian Piero
authors.initials: GP
authors.lastname: Spada
authors.forename: Irena
authors.initials: I
authors.lastname: Drevenšek-Olenik
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D003839:Deoxyadenosines / Q000737:chemistry; D003849:Deoxyguanosine / Q000737:chemistry; D006147:Guanine / Q000737:chemistry; D006151:Guanosine / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D011312:Pressure; D013499:Surface Properties; D013696:Temperature
chemical_list: D000538:Aluminum Silicates; D003839:Deoxyadenosines; D008055:Lipids; D006151:Guanosine; D006147:Guanine; D003849:Deoxyguanosine; C011934:mica