Electrochemical polymerization of azure A in H2SO4 solutions and properties of the polymer

The electrochemical polymerization of azure A on a platinum foil has been carried out by using cyclic voltammetry in the potential region of -0.2 and 1.3 V (vs. Ag/AgCl with saturated KCl solution). The electrolytic solution consisted of 5 mmol.dm(-3) azure A and 0.3 mol dm(-3) H2SO4. The temperature for polymerization was controlled at 323K. Poly(azure A) is a blue material. Poly(azure A) film has a electrochemical reversibility, stability and a fast charge transfer ability in the solution of 0.5 mol.dm(-3) Na2SO4 with pH <= 4.0. The conductivity of poly(azure A) is 1.5 x 10(-5) S.cm(-1) at 293K. The absorption peaks of poly(azure A) in the UV-visible spectrum appear at 258, 272 and 614 nm. The monomers are 254, 284 and 602 nm. The absorption peak of polymer at 614 nm is very broad and weak, which are different from that of the monomer. The Raman spectra of poly(azure A) are different from those of azure A. Poly(azure A) could be used for a immobilization of polyphenol oxidase to form a biosensor.