Preparation and characterization of silver nanoparticles-reduced graphene oxide on ITO for immunosensing platform

• Main Authors: Jamil, A., Lim, Hong Ngee, Yusof, Nor Azah, Ahmad Tajudin, Asilah, Huang, N. M., Pandikumar, A., Golsheikh, A. Moradi, Lee, Y. H., Andou, Y.
• Format: Article
• Language: English
• Published: Elsevier 2015
• Online Access: http://psasir.upm.edu.my/id/eprint/45959/1/Preparation%20and%20characterization%20of%20silver%20nanoparticles-reduced%20graphene%20oxide%20on%20ITO%20for%20immunosensing%20platform.pdf; http://psasir.upm.edu.my/id/eprint/45959/
• Institution: Universiti Putra Malaysia

We here report the in-situ electrochemical deposition of silver nanoparticles (AgNPs) and a reduced graphene oxide (rGO) nanocomposite on the surface of an indium tin oxide (ITO) electrode. The nanocomposite modified ITO was used as a basic platform for the construction of a novel electrochemical biosensor for the detection of hydrogen peroxide (H2O2); where horseradish peroxidase (HRP) tagged antibodies acted as recognition elements for carcinoembryonic antigen (CEA). The AgNPs-rGO/ITO modified electrode remarkably outperformed a bare electrode because of its enhanced surface area and electrocatalytic activity, resulting in a notably amplified electrical signal for the detection of H2O2. Through a cyclic voltammetric (CV) technique, the detection limit of the sandwich type immunoassay configuration was found to be 214 μM, with a linear range of 25–500 μM, as compared to the non-sandwich system, which was 120 μM with the same linear range. In contrast, the current–time response of the resulting sandwich-type immunoassay configuration showed a wider linear response to H2O2 in the range of 25–1450 μM, with a detection limit of 5.3 μM, while the non-sandwich system exhibited a linear range of 25–1355 μM (R2 = 0.9992), with a detection limit of 10 μM. Therefore, the current–time response provided a more sensitive means of detecting H2O2. The resulting immunosensor also exhibited outstanding stability and reproducibility, as well as selectivity toward H2O2 in the presence of several interferences.