RGO modified mediator free paper for electrochemical biosensing platform

Here, a novel, simple, cost-effective, environment-friendly, non-invasive and mediator free, reduced graphene oxide (RGO) modified paper-based biosensing platform was reported. A conductive platform was generated over the ivory paper sheet via in-situ reduction of graphene oxide. The conductivity of the RGO paper was found as 0.86 S cm−1. This substrate was used for deposition of cysteine capped gold nanoparticles (Cys-AuNPs) using electrophoretic deposition technique at 60 V for biosensing application. Scanning electron microscopic images show the deposition of Cys-AuNPs in the spherical bunch on the RGO paper. The Cys-AuNPs deposition on RGO paper was confirmed by energy-dispersive x-ray spectroscopy and X-ray photoelectron spectroscopy and used for immobilization of monoclonal antibodies. This paper-based immunosensor based on chronoamperometry technique has the ability of direct electron transfer without using any mediator. This platform can replace commercially available electrodes [Indium Tin Oxide (ITO) and fluorine-doped tin oxide (FTO)] coated glass substrate, glassy carbon and gold] for electronic and electrochemical applications including point-of-care (POC) devices.