Abstract: Polypyrrole (PPy) was synthesized by galvanostatic method using (1S)-(+)-10-camphorsulfonic acid ((+)-CSA) as the dopant, and the produced PPy was further overoxidized in the solution of (+)-CSA. Chiral microenvironment was successfully formed in the overoxidized PPy (OPPy) due to the synergistic effects of overoxidation and (+)-CSA, resulting in a twisted helical architecture of the OPPy chains. The formation of optical active OPPy was confirmed from the aspects of morphology (SEM and AFM) and circular dichroism (CD) spectra. Finally, an electrochemical chiral sensor was fabricated based on the resultant OPPy, which exhibits excellent biomolecular homochirality in the discrimination of tryptophan (Trp) enantiomers