Tuning polyelectrolyte-graphene interaction for enhanced electrochemical nonenzymatic hydrogen peroxide sensing

Highlights: • Polyelectrolyte-assisted noncovalent functionalization of graphene with good dispersion was reported. • Polyelectrolyte-graphene interaction can be efficiently tuned due to the occurrence of the intermolecular charge transfer. • The influence of the adsorbed polyelectrolytes on the redox of H₂O₂ and the related mechanism was investigated. • The resultant PDDA-graphene exhibited good electrocatalytic activity toward enzymeless hydrogen peroxide reduction. -- Abstract: Herein, tuning polyelectrolyte-graphene interaction was demonstrated to enhance electrocatalytic activity for non-enzymatic hydrogen peroxide detection. The introduction of positively charged poly(diallyldimethylammonium chloride) (PDDA) onto graphene surface not only prevent the aggregation of graphene sheets through electrostatic repulsion but also create net positive charge on adjacent carbon atoms in the graphene due to the occurrence of the intermolecular charge transfer by virtue of the robust electron-withdrawing ability of PDDA. Notably, we revealed the influence of the adsorbed polyelectrolytes on the redox of H₂O₂ and the related mechanism was discussed in detail. In a word, the catalytic activities of the graphene could be effectively tuned via the induction of the polyelectrolytes with different attributes. It was expected that this finding could be favorable for the tuning graphene electronic structure and further developing the novel graphene-based electrochemical sensing platforms.