Provided are a method of electrically modifying an electrode surface with dopamine-hyaluronic acid conjugates and technologies to suppress adsorption of harmful biomaterials and organisms by imparting anti-fouling to the electrode surface using the same and to maintain electrical properties of the electrode. More specifically, provided is a technology of coating an electrode surface via a dopamine functional group by electrochemically oxidizing dopamine-conjugated biocompatible polysaccharide polymers around the electrode. This aims to confirm the capability of suppressing organism adhesion depending on whether or not cells are adsorbed after coating the electrode surface, and to identify that electrochemical performance of the electrode is maintained or a slight increase in electrode resistance is kept, even after the electrode coating. The surface modified electrode according to the present invention can be widely used in the field of biomaterials such as bio-electrodes, bio-sensors and cell supports.
