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-α) 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-α antibody-antigen binding. A quantitative determination of the TNF-α detection performance was achieved by measuring the resistance changes with varying TNF-α 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-α sensor has a 0.43 pg mL-1 minimum detection limit and a linear range of 1-1000 pg mL-1.
Bibliographical noteFunding Information:
This research was supported by the National Research Foundation of Korea (Nos. 2015-022008, 2015-037739).
All Science Journal Classification (ASJC) codes
- Biomedical Engineering
- Materials Science(all)
- Condensed Matter Physics