Enzymatically synthesized polyaniline film deposition studied by simultaneous open circuit potential and electrochemical quartz crystal microbalance measurements

• Published in: Journal of colloid and interface science 2012-03, Vol.369 (1), p.103-110
• Main Authors: Carrillo, Norma, León-Silva, Ulises, Avalos, Tatiana, Nicho, M.E., Serna, Sergio, Castillon, Felipe, Farias, Mario, Cruz-Silva, Rodolfo
• Format: Article
• Language: English
• Subjects: Chemistry; Conducting polymers; Deposition; Electrochemical impedance spectroscopy; Electrochemistry; Electrodes; Enzymatic polymerization; Exact sciences and technology; General and physical chemistry; Microorganisms; Open circuit potential; Polyanilines; Polymerization; Quartz crystal microbalance; Quartz crystals
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2011.12.021

[Display omitted] ► Aniline enzymatic polymerization proceeds at remarkably low oxidation potential. ► A new method to monitor oxidoreductase enzymatic reactions is shown (OCP+QCM). ► PANI films were grown by in situ enzymatic polymerization and the mechanism was studied. The chemical and enzymatic deposition of polyaniline (PANI) films by in situ polymerization was studied and the resulting films were characterized. The film formation and polymerization processes were simultaneously monitored by the evolution of the open circuit potential and quartz-crystal microbalance measurements. Different substrates, such as Indium-Tin oxide electrodes and gold-coated quartz-crystal electrodes were used as substrates for PANI deposition. Electroactive PANI films were successfully deposited by in situ enzymatic polymerization at low oxidation potential. The electrogravimetric response of the enzymatically deposited PANI film was studied by cyclic voltammetry in monomer-free acidic medium. The morphology of the films was observed by scanning electron microscopy, revealing a granular structure in enzymatically deposited PANI. The PANI films were also characterized by thermogravimetric analysis, electrochemical impedance spectroscopy, and X-ray photoelectron and Fourier-transformed infrared spectroscopy. The simultaneous use of quartz crystal microbalance and open circuit potential is presented as a very useful technique to monitor enzymatic reactions involving oxidoreductases.