Scaly Graphene Oxide/Graphite Fiber Hybrid Electrodes for DNA Biosensors

The demand for a highly sensitive and stable DNA biosensor that can be used for implantable or on-time monitoring is constantly increasing. In this work, for the first time graphene oxide (GO) sheets are synthesized in situ at the surface of graphite fibers to yield scaly GO/graphite fiber hybrid electrodes. The partially peeled GO sheets, directly connected with the graphite fibers, not only provide a large number of binding sites for single-stranded DNA, but also favor high electron transfer rates from GO to the graphite fibers. Cyclic voltammetry (CV) confirms that the scaly GO/graphite fi ber hybrid electrode has excellent electrochemical activity. As a working electrode in an electrochemical impedance DNA biosensor, the fi ber hybrid electrode exhibits high selectivity, sensitivity, and stability. Due to its simplicity, low cost, high stability, small size, and unique microfiber morphology, the scaly GO/graphite fi ber hybrid electrode is an excellent candidate for an implantable biosensor. The method developed here could have a profound impact on the design of GO-based biosensors for DNA detection.