Clay-based graphite sensor for electrochemical determination of paranitrophenol in water samples

The electrochemical reduction of paranitrophenol (4-NP) has been studied on a carbon paste electrode (CPE) modified with Clay microparticles (Clay-CPE) using cyclic and differential pulse voltammetry. The clay microparticles were synthesized by exploring a new source from Akrach area situated in the west north, Morocco. Physicochemical characterization of the prepared clay was carried out using X−ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), energy dispersive X−ray analysis (EDX), and Fourier transform-infrared spectroscopy (FT−IR). During electrochemical measurements, the reduction current of 4−NP was much higher at Clay−CPE in Britton Robinson buffer solution (BR, pH2). 4-NP yields a well-defined reduction peak at Epc = −0.74 V which gradually increases in height with the concentration of the analyte in the range from 1.0 × 10 −5 mol L −1 to 1.0 × 10 −3 mol L −1 with a detection limit (DL) of 1.50 × 10 −6 mol L −1. The Clay−CPE has been used successfully for the determination of 4−NP in water samples.