A simple and sensitive electrochemical immunosensor for the detection of protein biomarker interleukin-6 (IL-6) based on gold nanoparticles (AuNPs) as label was reported. The signal of the immunosensor was originated from enlarged and positively charged AuNPs mediated electron transfer between insulating self-assemble monolayer (SAM) modified electrode and K 3 Fe(CN) 6 solution. The gold electrode was first modified with SAM to block the electron transfer between the electrode and K 3 Fe(CN) 6 solution. After the preparation of the immunosensor, the AuNPs attached onto electrode was enlarged and positively charged when treated in solution containing HAuCl 4 , ascorbic acid and cetyltrimethylammonium bromide (CTAB). The enlarged and positively charged AuNPs then mediated electron transfer between the electrode and K 3 Fe(CN) 6 solution, creating redox current that is proportional to the concentration of IL-6 detected. The reported immunosensor has high sensitivity and wide linear range. This novel signal amplification strategy can be applied to the detection of different kinds of protein biomarkers. © 2011 Elsevier B.V. All rights reserved.
Deng, C., Qu, F., Sun, H., & Yang, M. (2011). Sensitive electrochemical immunosensor based on enlarged and surface charged gold nanoparticles mediated electron transfer. Sensors and Actuators, B: Chemical, 160(1), 471–474. https://doi.org/10.1016/j.snb.2011.08.010