Avidin–Biotin Technology in Gold Nanoparticle-Decorated Graphene Field Effect Transistors for Detection of Biotinylated Macromolecules with Ultrahigh Sensitivity and Specificity
Shiyu Wang, Md. Zakir Hossain, Tao Han, Kazuo Shinozuka, Takaaki Suzuki, Anna Kuwana, Haruo Kobayashi
Abstract
/Si substrate. The sensing performance of AuNP-GFET was characterized by the real-time two-terminal electrical current measurement upon injection of the analyte solution into a silicone pool preattached onto the electrodes. Avidin, a tetrameric biotin-binding protein with strong affinity and specificity, immobilized on AuNP-decorated single-layer graphene, was used as the sensing platform and transduced the electrical signal upon binding to the analyte macromolecules. The sensing capability of the AuNP-GFET was tested with the biotinylated protein A. Sensitivity of the present biosensor was estimated to be ∼0.4 pM. The specificity and applicability of the biosensor were confirmed using both synthetic and real samples. Because the biotin label can retain its binding capability to avidin with strong affinity and specificity even after conjugating with varieties of proteins and nucleotides, the present AuNP-GFET biosensor is expected to promote the research in developing different biosensors.