Electrochemical immunosensor based on AuNPs/PDDA-GO for detection of SirT1

AuNPs/PDDA-GO nanocomposite was produced by combining poly(diallyldimethylammonium chloride)(PDDA) functionalized graphene oxide nanosheets(PDDA-GO) and gold nanoparticles(AuNPs) through self-assembly method, which offered an efficient platform for antibody immobilization with good biocompatibility. A new type of electrochemical immunosensor based on AuNPs/PDDA-GO nanocomposite for the detection of SirT1 was then developed. The immunosensor construction consisted of the immobilization of the hybrid architecture, the immunoreaction of target antigen SirT1 and capture antibody(Ab₁), followed by the binding of HRP-Ab₂. The designed immunoassay showed an excellent analytical performance, and exhibited a wide dynamic response range for SirT1 from 0.1 ng/mL to 100 ng/mL with a detection limit of 0.029 ng/mL. Overall, this developed strategy is proved as a simple, cost-effective method, and can be easily extended to other protein analysis.