ELECTROCHEMICAL DETECTION OF PICRIC ACID USING GLASSY CARBON ELECTRODE MODIFIED REDUCED GRAPHENE OXIDE BY SINGLE-DROP MICROEXTRACTION METHOD.

The reduced graphene oxide composite-modified glassy carbon electrode (rGO/GCE) was developed as a simple, selective and sensitive electrochemical sensor for determination of picric acid (PA). The rGO was obtained by reduction of graphene oxide obtained via Hummer?s method. The synthesisedrGO was characterized using Fourier transform infrared spectroscopy (FTIR) and transmission Electron microscopy (TEM). GCE was modified with rGO and the electrochemical properties of the bare and modified electrode were investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results obtained showed that the modified electrode exhibited more excellent electrochemical properties than the bare GCE. The optimum conditions for detection of PA in water using CV and EIS were as follows: deposition potential at 100 mV/s, pH 2, and 0.5 M H2SO4was used as supporting electrolyte. The linear regression equation obtained was I (μA) = 0.6432C + 7.2359 and the detection limit were calculated to be 0.65 μg L−1.