Synthesis and electropolymerization of a new conjugated dithieno(3,2-b:2′,3′-d) pyrole (DTP) derivative, namely, 2-(2-(2-(4H-dithieno[3,2-b:2′,3′-d]pyrrol-4-yl)ethoxy)ethoxy)ethanamine, (DTP-alkoxy-NH2) monomer are presented. The electrochemical, spectroelectrochemical effects and biosensor capability towards to glucose oxidase enzyme of P(DTP-alkoxy-NH2) polymer film are investigated in detail during the placement of alkoxy-NH2 functional unit in the polymer. Electrochemical and optical results between neutral and oxidized states of the polymer film show that (P(DTP-alkoxy-NH2)) has reversibly multielectrochromic behaviors. Furthermore, glucose oxidase enzyme (GOx) is covalently immobilized on Au electrodes modified with P(DTP-alkoxy-NH2) conducting polymer. This enzyme is entrapped into conducting polymer during electropolymerization of DTP monomer on the electrodes. Some characterization parameters (Maximum reaction rate, Michaelis–Menten constants, temperature, pH and operational stabilities) for this kind of biosensor application is also determined.