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p‐Nitrophenol (p−NP) is a high priority toxic pollutant and that has harmful effects on human, animals and plants. Thus, the detection and determination of p−NP present in the environment is an urgent as well as highly important requisite. The present article, therefore focused on the construction of a novel electrochemical sensor based on NiO nanoparticles/α‐cyclodextrin functionalized reduced graphene oxide modified glassy carbon electrode (NiO−NPs‐α‐CD‐rGO‐GCE) for the selective and sensitive detection of p−NP. UV‐vis, high resolution transmission electron microscopy (HR‐TEM), selected area electron diffraction pattern (SAED) and X‐ray diffraction (XRD) analysis confirms the formation of highly pure NiO nanoparticles. Field emission scanning electron microscopy (FE‐SEM), energy dispersive X‐ray spectroscopy (EDS), and cyclic voltammetry (CV) were used to characterize the step‐wise electrode modification process. DPV was carried out to quantify p−NP within the concentration range of 1−10 μM and found the detection limit of 0.12 nM on the basis of the signal‐to‐noise ratio S/N=3. The electrode can able to detect different isomers of nitrophenols. Interferences of other pollutants such as phenol, p‐aminophenol, o‐ and m‐ nitrophenol, 4‐chlorophenol, 2,6‐dichlorophenol and ions like K+, Cd2+, Cl−, SO42− did not affect the sensing of p−NP. The newly developed sensor exhibited diffusion controlled kinetics and had excellent sensitivity, selectivity and reproducibility for the detection of p−NP. The electrode showed good recoveries in real sample analysis. [ABSTRACT FROM AUTHOR]

The study presents a novel paracetamol (PA) sensor based on Pd nanoparticles (PdNPs) deposited on carboxylated graphene oxide (GO−COOH) and nafion (Nf) modified glassy carbon electrode (GCE). The morphologies of the as prepared composites were characterized using high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), and fourier transform infrared spectroscopy (FTIR). The experimental results demonstrated that Nf/GO−COOPd displayed excellent electrocatalytic response to the oxidation PA. The linear range was 0.04–800 μM for PA with limit of detection of 0.012 μM and excellent sensitivity of 232.89 μA mM−1 cm−2. By considering the excellent performance of Nf/GO−COOPd composite such as wider linear range, lower detection, better selectivity, repeatability, reproducibility, and storage stability, the prepared composite, especially GO−COOH support, with satisfactory electrocatalytic properties was a promising material for the modification of electrode material in electrochemical sensor and biosensor field. [ABSTRACT FROM AUTHOR]