Polymeric gels defined as soft and solid-like systems that enable to retain a large volume of solvent and their high molecular weight provides long-term stability without crystallization. Therefore, the use of polymeric gels in the fields of energy and sensor technologies has become advantageous. In this thesis, the polymeric gel is successfully synthesized on the gold surface by Aza-Michael addition reaction of the polyester scaffold with a triple covalent bond and branched polyethyleneimine which is a secondary amine source. The polyester-polyethyleneimine based gel was generated on the isocyanate functionalized gold surface by using the grafting-to methodology. The morphology of the surface and thickness of the coating can be adjusted by layer-by-layer reactive coating on the gold surface of polymer structures. Electroactive properties are acquired for different application areas of the synthesized gels. To provide modular electron transfer, polyethyleneimine was modified with ferrocene carboxaldehyde prior to obtaining gel on the surface. The gel interface on the gold surface will increase the surface area and activity due to its three-dimensional structure and adjustable morphology. The number of the immobilized structures, the electroactive species in a unit area and electron transfer increases. The modified electrode surfaces coating yields and electroactivity examined with electrochemical methods, Cyclic Voltammetry and Electrochemical Impedance Spectroscopy. The morphological properties investigated by Atomic Force Microscopy. Additionally, polyester-based gels lithium-ion conductivity was investigated. Dissociation of lithium perchlorate in the gel and enhancing the conductivity was investigated. Indium tin oxide coated glasses were used as an electrode to characterize lithium ion conductivity.