Electrochemical Properties of Poly(Azure A) Films Synthesized in Sodium Dodecyl Sulfate Solution

Abstract

Radicalization of azure A monomers, a phenothiazines class heterocyclic compound, was carried out by cyclic voltammetry in sodium dodecyl sulfate micellar aqueous solutions for the first time, which allowed poly(azure A) films (PAA(DS)) to be deposited on the electroactive surface of different electrodes. In particular, this work focused on the electrochemical behavior of PAA(DS) films deposited on screen-printed carbon electrodes. To this end, electrochemical techniques, including cyclic voltammetry and electrochemical impedance spectroscopy were employed. The Ru(NH3)63+/2+ redox probe was used to characterize the electroactive area of the PAA(DS)-modified electrodes, with the support of SEM images. The PAA(DS) electrochemical mechanism involves anions transfer and protons transfer in KCl solutions, where the anion transfer is probably slower than the proton transfer. The electrochemical reactivity of PAA(DS) films toward reduced nicotinamide adenine dinucleotide (β-NADH) was compared with other PAA films synthesized in the presence of different inorganic anions under identical experimental conditions. The obtained data showed that PAA(DS) films had better electrocatalytic properties than the same polymer electrogenerated with other inorganic anions, such as Cl−, F−, HPO2 −4, H2PO−4, NO−3 and SO2 −4. This opens up the possibility for further applications as new electrochemical sensing platforms with enhanced capabilities.