Electrochemical properties of seamless three-dimensional carbon nanotubes-grown graphene modified with horseradish peroxidase

•Seamless 3D MWNTs-graphene hybrid employed as conductive nanoscaffold for enzymes•Electrochemical properties of HRP-modified 3D hybrid investigated•Compared with graphene-HRP 3D hybrid-HRP gives higher reduction currents to H2O2.•Direct electron transfer kinetics from 3D hybrid to HRP compound I and II analyzed

Horseradish peroxidase (HRP) was immobilized through sodium dodecyl sulfate (SDS) on the surface of a seamless three-dimensional hybrid of carbon nanotubes grown at the graphene surface (HRP-SDS/CNTs/G) and its electrochemical properties were investigated. Compared with graphene alone electrode modified with HRP via SDS (HRP-SDS/G electrode), the surface coverage of electroactive HRP at the CNTs/G electrode surface was approximately 2-fold greater because of CNTs grown at the graphene surface. Based on the increase in the surface coverage of electroactive HRP, the sensitivity to H2O2 at the HRP-SDS/CNTs/G electrode was higher than that at the HRP-SDS/G electrode. The kinetics of the direct electron transfer from the CNTs/G electrode to compound I and II of modified HRP was also analyzed.

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