Multifunctional materials with excellent biocompatibility and electron-transport properties are critical for the pursuit of point-of-care biosensing devices. The authors report the synthesis of zinc oxide-reduced graphene oxide (ZnO-rGO) nanocomposite for the fabrication of an electrochemical immunosensing test-bed for noninvasive onsite detection of oral cancer biomarker (interleukin-8, IL8). The immunosensor showed successful detection of IL8 at low concentration ranges, i.e., 100 fg/mL-5 ng/mL with a sensitivity of 12.46 +/- 0.82 mu A mL/ng and a detection limit of 51.53 +/- 0.43 pg/mL. These results have been validated through in vitro investigations using real saliva samples spiked with IL8
