Development of an Admittance Sensor for Isoniazid using Differential Coulometric FFT Admittance Voltammetry in a Flow Injection Analysis System

In this work, for the first time, a new electrochemical detection system for Isoniazid was developed using combination of modified carbon paste electrode with Coulometric fast Fourier transformation admittance voltammetry (CFFTAV). The sensor was fabricated by using graphite powder, SiC nanoparticles and ionic liquid (CILSiCE), and casting reduced graphene oxide, ionic liquid, SWCNT, and gold nanoparticles. This electrode was characterized by SEM and electrochemical impedance spectroscopy methods. In the optimal conditions, the electrode exhibited a linear response to Isoniazid from 0.5 to 300 nM and detection limit was 0.15 nM. Moreover, the proposed sensor exhibited good accuracy and repeatability (R.S.D value of 2.45%) and long term stability, up to 70 days with a decrease of 4.1% in the response. The proposed method was used to the determination of Isoniazid in real samples, successfully.