In this study, a new type of two-dimensional (2D) hybrid heterostructure was demonstrated by electrostatic assembling the anionic sulfonated graphene sheets (SGS) and positively charged gold nanoparticles (GNPs). In this strategy, water-dispersible sulfonated graphene dispersions were synthesized by covalently binding sulfonic acid groups in reduced graphene oxide. Then, the negative charge of SGS was strong enough to drive the formation of the 2D nanomaterials with positively charged GNPs through electrostatic interaction. Furthermore, we utilized the as-prepared GNPs/SGS nanocomposites as the electrochemical enhanced material for H2O2 sensing (as the model analyte). The GNPs/SGS-modified glassy carbon electrode showed improved electrochemical catalytic ability toward electrochemical reaction of H2O2, and thus a rapid response, wide linear range and low detection limit were obtained using the chronoamperometry technique. This work might find promising applications in developing a new type of enzymeless biosensor.