Mechanism research of SDBS-functionalized polypyrrole to improve electrochemical performance of screen-printed graphene electrode

•A novel method to enhance the response sensitivity of screen-printed graphene electrode (SPGE) by modifying functionalized polypyrrole (PPy) is proposed.•The sensitivity mechanism was investigated by experimental characterization and density functional theory calculations.•The doping of DBS-ions improves the dispersion of SDBS-functionalized polypyrrole.•The synergistic effect of PPy and DBS-ions enhanced the response sensitivity of SPGE to potassium ferricyanide.