Preparation and characterization of bismuth oxide nanoparticles-multiwalled carbon nanotube composite for the development of horseradish peroxidase based H2O2 biosensor

► Bi2O3-MWCNT nanocomposite was prepared by simple two-step solution phase approach. ► Direct electrochemistry of HRP was revealed at Bi2O3-MWCNT surface. ► 1% nafion coating was optimum for best biosensor response. ► Nanocomposite matrix decreased over potential for H2O2 reduction.