Impedimetric Tumor Necrosis Factor-α Sensor Based on a Reduced Graphene Oxide Nanoparticle-Modified Electrode Array

A surface was prepared by simple electrodeposition of reduced graphene oxide (RGO) coated with gold nanoparticles (AuNP) on an indium tin oxide microelectrode array, and its ability and applicability in a tumor necrosis factor-alpha (TNF-alpha) detection sensor was evaluated by electrochemical impedance spectroscopy (EIS). The AuNP-RGO hybrid structure showed improved electrical conductivity when compared with the conductivities of its individual elements and demonstrated an excellent capturing ability for TNF-alpha antibody-antigen binding. A quantitative determination of the TNF-alpha detection performance was achieved by measuring the resistance changes with varying TNF-alpha concentrations while using a [Fe(CN)(6)](3-/4-) redox probe in EIS. The antibody covered electrode resistance increases approximately linearly (r = 0.969) with increasing antigen concentration. The proposed TNF-alpha sensor has a 0.43 pg mL(-1) minimum detection limit and a linear range of 1-1000 pg mL(-1).