Gold nanoparticles coated zinc oxide nanorods as the matrix for enhanced L-lactate sensing.

•Au nanoparticles were coated on ZnO nanorods via electrostatic self-assembly.•The electro-catalytic properties of electrode were enhanced by Au nanoparticles.•Au/ZnO based biosensor exhibited improved sensing performance for l-lactate.•The electrode with Au modification displays better affinity of LOx to l-lactate.•The present method can be used for detecting other biological and chemical species.