Novel Electrochemical Method for the Characterization of the Degree of Chirality in Chiral Polyaniline

A novel method to indicate the degree of chirality in polyaniline (PANI) was developed. The ( d ‐camphorsulfonic acid)‐ and (HCl)‐PANI‐based electrodes exhibited significantly different electrochemical performances in d ‐ and l ‐Alanine (Ala) aqueous solution, respectively, which can be used for the characterization the optical activity of chiral PANI. Cyclic voltammogram, tafel, and open circuit potential of PANI‐based electrodes were measured within d ‐ and l ‐Ala electrolyte solution, respectively. The open circuit potentials under different reacting conditions were analyzed by Doblhofer model formula, in which C⁺]_poly1/C⁺]_poly2 was used as a parameter to characterize the degree of chirality in chiral PANI. The results showed that C⁺]_poly1/C⁺]_poly2 can be increased with increasing concentrations of (1S)‐(+)‐ and (1R)‐(?)‐10‐camphorsulfonic acid. In addition, we detected that appropriate response time and lower temperature are necessary to improve the degree of chirality. Chirality 25:39‐42, 2013.© 2012 Wiley Periodicals, Inc.