Hybrid nanomaterial/catalase-modified electrode for hydrogen peroxide sensing

Conjugation of biomolecules with hybrid nanomaterials offer opportunities in the assembly of (bio)sensors of improved electrochemical performance. This work reports on developing a novel catalase-functionalized hybrid nanomaterial for the detection of hydrogen peroxide (H2O2). The rationally assembled (bio)sensor consists of iron nanoparticles coated with graphene's layers supported on multi-walled carbon nanotubes (Fe@G-MWCNTs), deposited at a screen-printed carbon electrode surface and functionalized with catalase. Transmission electron microscopy, X-ray diffraction-, X-ray photoelectron- and thermogravimetric-analysis were used to characterize the physicochemical properties of the hybrid nanomaterial and better understand its electrochemical behavior. The (bio)sensor response was linear from 0.1 to 7 mM, with a sensitivity of 0.059 ?A/(?M.cm2), a limit of detection of 28.2 ?M, a MichaelisMenten constant of 17.9 mM, and high reproducibility. The graphene flakes acted as a protective layer that prevented the loss of the Fe nanoparticles activity, thus improving the long-term stability of the (bio)sensor.

Automated summary

The development of a novel catalase-functionalized hybrid nanomaterial for H2O2 detection has been reported in this study, demonstrating improved electrochemical performance of the sensor through the rational assembly of iron nanoparticles coated with graphene layers supported on multi-walled carbon nanotubes. The graphene flakes acted as a protective layer to prevent the loss of Fe nanoparticles activity and enhance the long-term stability of the sensor.