Development of a novel sensor for isoniazid based on 2,3-dichloro-5,6-dicyano-p-benzoquinone and graphene: Application in drug samples utilized in the treatment of tuberculosis

• A novel platform for electrocatalysis of Isoniazid based on DDQ/rGO immobilized in a Nafion® membrane was developed;
• The sensor is a sensitive, precise, robust and stable sensor for Isoniazide;
• The sensor was successfully applied for Isoniazide determination in drug samples utilized in the treatment of tuberculosis.

A novel platform for electrocatalysis of isoniazid (INH) based on 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and reduced graphene oxide (rGO) immobilized in a Nafion® membrane was developed. The composite (DDQ/rGO) was characterized by Fourier-transform infrared spectroscopy (FTIR) and the sensor response for the analyte was studied by cyclic voltammetry (CV) and chronoamperometry techniques. The DDQ/rGO/Nafion® modified electrode showed an excellent electrocatalytic activity toward INH oxidation with a decrease of the overpotential of about 660 mV vs Ag/AgCl, compared to the process at an unmodified electrode. Under optimized conditions, the sensor showed a wide linear range for isoniazid from 0.5 up to 380 μmol L− 1 with r2 of 0.999. The sensor was applied for the INH determination in drug samples utilized in the tuberculosis treatment and the results were satisfactory. The detection limit, repeatability, long-term stability, time of response and linear response range were also investigated.