Cobalt phthalocyanine substituted with tetrabenzimidazole (CoTBIPc) moieties has been synthesized by novel method using tetracarboxylicacid phthalocyanine. The synthesized substituted phthalocyanines were characterized by absorption spectroscopy, FTIR, XRD and TGA. The synthesized benzimidazole compound was stable upto 500 degrees C and showed amorphous nature. The CoTBIPc complex was characterized by cyclic voltametry and exhibited the redox behavior corresponding to the central metal (Co+2/Co+1) of the CoTBIPc. The secondary amine of the benzimidazole ring undergoes electropolymerization on the glassy carbon electrode (GCE) during potential cycling. The electropolymerized film of CoTBIPc on GCE (GCE/poly(CoTBIPc) was used for the detection of H2O2. Further, in order to enhance the surface area, conductivity and sensitivity, the electropolymerization of CoTBIPc was performed on graphene oxide (GO) coated GCE (GCE/GO/poly(CoTBIPc). The GCE/GO/poly(CoTBIPc) showed enhanced catalytic behavior compared to GCE/poly(CoTBIPc) and the H2O2 detection is linear in the concentration range of 3 to 160 mu M and 2 to 300 mu M on GCE/poly(CoTBIPc) and GCE/ GO/poly(CoTBIPc) respectively. The amperometric sensor was fabricated using GCE/poly(CoTBIPc) and GCE/ GO/poly(CoTBIPc) and it showed linear response for the detection of H2O2 in the concentration range 3 to 140 mu M and 2 to 200 mu M respectively. The LOD values for H2O2 detection on GCE/poly(CoTBIPc) and GCE/GO/poly(CoTBIPc) by amperometry are 0.8 and 0.6 mu M respectively. The modified GCE/GO/poly(CoTBIPc) shows greater reproducibility, repeatability and high stability, without losing its catalytic property. The modified electrode has high selectivity for H2O2 even in the presence of interfering species in solution.