Graphene oxide supported liposomes for efficient label free electrochemical DNA biosensing

Liposome and graphene are studied towards the development of biocompatible materials for DNA sensing and target delivery applications. In this study, liposomes are supported on various graphene materials on gold surface by physisorption without using thiol self-assembled monolayers. Reduced graphene oxides (rGO) are prepared by chemical (ascorbic acid and hydrazine) and electrochemical reduction methods. Studies indicate that the bilayer formation of cationic 1,2-dioleoyltrimethylammoniumpropane (DOTAP) on the graphite, graphene, graphene oxide and chemically reduced GO is due to thick layers of these materials. The thin layered rGO produced through mild electrochemical reduction in the acidic medium (favors selective reduction of hydroxyl and epoxide functional group) is suitable for the tethering intact vesicle structure of the DOTAP confirmed by different surface characterizing techniques. The intact vesicle structure is applied for label free sensing of DNA in the dynamic range from 10−15 to 10−9 M to demonstrate the feasibility of the sensor for molecular diagnosis.