A novel non-enzymatic H2O2 sensor was fabricated by electrodepositing 5–16 nm AuNPs onto porous GaN electrode. As far as I know, this is the first time to report porous GaN based electrochemical H2O2 biosensor. Our work focuses on the design of simply prepared and good practicability H2O2 biosensor. There is no doubt that our work has wider societal impact.