Graphene oxide obtained through liquid ex-foliation of graphite flakes by improved Hammer's method have been functionalized with stilbene-4, 4'-dicarboxylic acid and aniline and electrochemical performance of covalently functionalized graphene oxide was investigated. All samples were characterized through FTIR, XRD, FESEM, UV-Vis and electrochemical performance was measured through cyclic voltammetry (CV) analyzer. High level of oxidation was observed in graphene oxide and 002 plane of graphene oxide was confirmed at 10.30. It was found that with the functionalization of graphene oxide, the capacitance increased up to four and two times for stilbene-4, 4'-dicarboxylic acid and aniline modified graphene oxide respectively. The optical absorption was red shifted as high as 104 nm wavelength, showing higher conjugation effect in stilbene-4, 4'-dicarboxylic acid modified graphene oxide as compared to 45 nm in the case of aniline modified graphene oxide