L -Cysteine functionalized Nd 2 O 3 /rGO modified glassy carbon electrode: A new sensing strategy for the rapid, sensitive and simultaneous detection of toxic nitrophenol isomers

A simple, efficient and selective sensor was successfully developed for the rapid, simultaneous detection and quantification of nitrophenol isomers i.e. o-nitrophenol and p-nitrophenol using L -cysteine functionalized Nd 2 O 3 /rGO nanocomposite. Structural and morphological properties of L -cysteine functionalized Nd 2 O 3 /rGO was studied by various advanced characterization techniques including X-ray diffraction technique (XRD), UV–visible spectroscopy (UV-Vis.), Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM) and Energy dispersive X-ray studies (EDX). The electrochemical features of the novel sensor were studied via electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Whilst, square wave voltammetric mode was used to quantify environmentally harmful nitro phenolic contaminants i.e. o-NP and p-NP under optimized conditions. The developed sensor induced remarkable electrocatalytic activity and conductivity to the reduction of nitrophenol isomers with wide linear response range from 0.05 to 50 µM along with low detection limit of 0.01 µM and 0.02 µM for o-NP and p-NP respectively. Furthermore, the fabricated electrochemical sensor showed good selectivity over some likely interferents. The practical applicability of developed electrode material was also tested in tap water and satisfactory results were obtained. These results suggested that the developed protocol can also be used for ultrasensitive electrochemical determination of other toxic environmental pollutants in water samples.