Potentiometric urea biosensor based on poly(glycidylmethacrylate)-grafted iron oxide nanoparticles

► Urea biosensor is fabricated with immobilization of urease on PGMA-grafted Fe3O4 on Au electrode. ► The biosensor seems to be fast to respond and sensitive. ► The PGMA-grafted Fe3O4 NPs could be used to construct a range of biosensors.