Adsorption and hybridisation of DNA-surfactants at fluid surfaces and lipid bilayers

Abstract

In this paper, we explore the properties of a novel class of functional surfactants based on DNA. These DNA-based surfactants are short chain DNA oligonucleotides covalently attached to a large hydrophobic group, which makes the modified DNA molecules amphiphilic and allows DNA chains to be adsorbed and oriented at fluid surfaces. We show that these materials are surface-active at various fluid surfaces, including air–water and oil–water interfaces, as well as lipid bilayers. We demonstrate that once adsorbed the DNA-surfactants used remain on the liquid surface upon hybridisation with a complementary DNA chain. We use complementary DNA-surfactants to functionalise fluid surfaces and to program the interactions between them based on Watson–Crick pairing. By selecting the appropriate DNA base sequences the interaction between the fluid surfaces functionalised with DNA-surfactants can be programmed with the level of specificity of the enzyme–substrate interaction. We also suggest a novel type of aqueous ink based on DNA-functionalised small liposomes for micropatterning of solid surfaces with DNA by a microcontact printing technique. We illustrate the capabilities of this technique by specific deposition of complementary DNA-functionalised liposomes onto DNA-micropatterned solid surfaces.