Incorporation of aptamer in mixed Langmuir-Blodgett films between lipid and graphene oxide sheets

Interaction between different molecules during formation of complex nanostructured films, which can be used as matrixes for fixing of macromolecules, plays important role in formation of sensitive films for biosensors. The Langmuir-Blodgett technique was used to obtain mixed films of dimethyldioctadecylammonium bromide (DODAB) and graphene oxide sheets (GO). Specific aptamers were subsequently attached. The obtained results after characterization of films on the air/water interface show that incorporation of GO sheets between lipid monolayers takes place. Transfer rates for mixed films indicates the formation of Z-type films after GO incorporation. Quartz Crystal Microbalance measurements of films density clearly demonstrated the presence of GO sheets in films. After drop casting method with the solution of aptamer marked with Cy5 fluorophores on the surface of the mixed films, measurements of fluorescence microscopy and contact angle were performed demonstrating the presence of these macromolecules even after cleaning procedures. (C) 2019 Elsevier Ltd. All rights reserved.