Abstract
An electrochemical sensor was developed by using poly(3,4-ethylenedioxy thiophene) electrode in presence of different types of surfactants. Voltammetric behavior of isoniazid was studied at this electrode in the presence and absence of SDS and CTAB and interesting electrocatalytic effects were found. The presence of surfactant in the medium plays a key role in the electrostatic attraction and repulsion of isoniazid towards the polymeric surface in different pH values. The electrochemical behavior of isoniazid was investigated by cyclic voltammetry, linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS). The linear response obtained for isoniazid was in the range of 0.1 to 8 µmol L-1 and 10 to 100 μmol L-1 with correlation coefficients of 0.999 and 0.998 and detection limits 32 nmol L-1 and 45 nmol L-1, respectively. The utility of this modified electrode was demonstrated for the determination of INH in human urine.