Electrochemical immunoassay based on gold nanoparticles and reduced graphene oxide functionalized carbon ionic liquid electrode

► AuNPs and poly(l-Arginine)/graphene composite modified carbon ionic liquid electrode. ► Combined advantages of graphene, AuNPs, poly(l-Arginine) and ionic liquid. ► Enhanced electrochemical response of carcinoembryonic antigen immunosensor. ► The immunosensor has low detection limit and wide linear range.