Sensitive electrochemical immunosensor for platelet-derived growth factor in serum with electron transfer mediated by gold nanoparticles initiated silver enhancement

Abstract

Sensitive electrochemical immunosensor for the detection of platelet-derived growth factor BB (PDGF-BB) based on metal nanoparticles mediated electron transfer was reported. The immunosensor was prepared on insulating self-assembled monolayer (SAM) modified gold electrode using gold nanoparticles (AuNPs) as electrochemical label. The attachment of AuNPs onto the electrode through the formation of the sandwich immuno-complex altered the insulating properties of the electrode, and in return mediates electron transfer between electrode and a redox indicator, Fe3(CN)63-, resulting in redox current. The redox current was further enhanced with the deposition of silver nanoparticles onto electrode using AuNPs acts as nuclei. Under optimized experimental conditions, the redox current is dependent on the amount of metallic silver deposited onto the electrode surface, which in return is proportional to the concentration of PDGF-BB detected. The immunosensor has high sensitivity, selectivity and wide linear range (0.005–10ng/mL). This immunosensor preparation method may find wide applications for the detection of other proteins.