Non-enzymatic electrochemical detection of hydrogen peroxide on highly amidized graphene quantum dot electrodes

•Infrared (IR) method was used to synthesize amidized graphene quantum dots (GQDs).•The GQDs served as metal-free catalysts for electrochemically detecting H2O2.•The catalytic cycle involved adsorption of H2O2 and two-stage charge transfer step.•Substitutional N atoms provided additional electroactive sites for adsorbing H2O2.•The GQD electrode exhibited a high selectivity of 1.83 μA mM−1 cm−2 in 0.5–40 mM.