Two chiral poly(N-(tert-butoxycarbonyl)-Lphenylalayl (3,4-ethylenedioxythiophene-2'-yl)methylamide) (PEDOT-Boc-L-Phe) and poly(L-phenylalayl (3,4ethylenedioxythiophene-2'-yl)methylamide) (PEDOT-L-Phe) were synthesized by electrochemical polymerization, and their properties as an immobilization platform for biosensor application were explored. After covalent immobilization of ascorbate oxidase (AO) on the polymeric matrixs, their applications for ascorbic acid (AA) biosensing were investigated in detail. Importantly, optimized biosensors showed very good linear relationships between [AA] and the steady-state current response (I) in the concentration range of 0.03 μM to 7 mM (y = 0.08972 x + 0.5785, r = 0.9954, (PEDOT-Boc-Phe)) and 0.07 μM to 7 mM (y = 0.0397x + 0.59381, r = 0.9928 (PEDOT-Phe)), respectively. Satisfactory results implied that the as-formed polymer films were realized the immobilization of biologically active species and could be candidates in the development of biosensing performance.