Electrochemical Preparation of Poly(acriflavine) Film‐Modified Electrode and Its Electrolcatalytic Properties Towards NADH, Nitrite and Sulfur Oxoanions

Abstract

AbstractElectrochemical polymerization of acriflavine (AF) was carried out onto glassy carbon electrodes (GCE) from the aqueous buffer solution containing 1.5×10−3 M AF monomer (pH 3.5) which produced a thin electrochemically active film. This is noted as poly(AF) film modified electrodes (PAF/GCE). This modified electrode was shown a stable reversible redox couple centered at +0.22 V in pH 3.5 buffer solutions. PAF/GCE was found to be more stable in acidic solutions and its formal potential was found to be pH dependent with a slope close to −60 mV/pH. The electrochemical deposition kinetics of poly(AF) onto gold coated quartz crystal was studied by using electrochemical quartz crystal microbalance (EQCM) combined with cyclic voltammetry (CV). PAF/GCE was found be good mediator for electrochemical oxidation of reduced nicotinamide adenine dinucleotide (NADH) in pH 5 buffer solutions. The electrocatalytic oxidation of SO$\rm{ _3^{2 - } }$ and electrocatalytic reduction of NO$\rm{ _2^ - }$, SO$\rm{ _5^{2 - } }$ and S2O$\rm{ _8^{2 - } }$ were carried out at PAF/GCE electrode in acidic aqueous solutions. The electrocatalytic oxidation of NADH was also investigated by using amperometric method.