Graphene loaded bimetallic Au@Pt nanodendrites enhancing ultrasensitive electrochemical immunoassay of AFP

A dual enhancing strategy has been employed to develop electrochemical immunosensor for the ultrasensitive detection of AFP, which is enhanced by poly-dopamine functionalized N-doped multi-walled carbon nanotube (PDA-N-MWCNT) and the nanocomposite of graphene loaded Au@Pt mesoporous nanodendrites. The fabricated immunosensor exhibited a wide linear range of 0.1   pg/mL–10   ng/mL, with an ultralow detection limit of 0.05   pg/mL. The good performance of the developed immunosensor could be contributed to (1) PDA-N-MWCNT supplied good biocompatible surface for immobilizing primary antibody (Ab 1 ); (2) PDA-N-MWCNT modified electrode endowed more electrochemical active area, which can effectively improve the sensitivity of the immunosensor; (3) graphene could load high amount of good conductive and high electrocatalytic active Au@Pt nanodendrites for signal amplification . The results imply that the as-fabricated immunosensors have great potential for clinic usage.