Graphene oxide arrays for detecting specific DNA hybridization by fluorescence resonance energy transfer

The unique properties of graphene oxides (GO) such as water dispersibility, versatile surface modification, and photoluminescence make them suitable for biological applications. In this study, we explored the use of GO sheets as a novel DNA biosensor by applying the GO in an array format to recognize specific DNA-DNA hybridization interaction. When the probe DNA linked to the surface of GO by using carbodiimide chemistry is hybridized with a gold nanoparticle (Au NP) labeled complementary DNA strand, the fluorescence emission intensity of the GO array is drastically reduced. TEM data reveal that the Au NPs are dispersed on the GO surface, particularly at edges and folded structures upon hybridization with a density of approximately 80 Au NPs per microm(2). This leads to ca. 87% fluorescence quenching as a consequence of fluorescence energy transfer between Au NPs and the GO sheets. These results suggest that the GO nanomaterials, which are readily synthesized on a large scale from a cheap graphite source, could have a wide range of bioapplications in the fields of biosensors, molecular imaging and nanobiotechnology.