Direct electrochemistry and electrocatalysis of myoglobin immobilized in calcium alginategraphene microsphere films

In the present work, calcium alginate-graphene (CA-graphene) microspheres have been prepared and used to immobilize myoglobin (Mb) for fabricating electroactive Mb-CA-graphene microsphere thin films on the electrode surface. The morphology and structure of Mb-CA-graphene microsphere films were characterized by scanning electron microscopy (SEM) and UV-vis spectroscopy. These structural merits with the synergistic effect of CA microspheres and graphene sheets lead to a high electrochemical and electrocatalytic activity performance for Mb. The direct electrochemistry of Mb immobilized on this blend, CA microspheres containing graphene, was realized, and demonstrated good electrocatalytic properties toward reduction of various substrates, such as hydrogen peroxide (H2O2), sodium nitrite (NaNO2) and trichloroacetic acid (TCA). CA-graphene microsphere films will find wide potential applications in environmental analysis and biomedical detection.