Electro-sensing base for hazardous pesticide 2, 4-DCP and its quantification in real samples at ZnO@Cu core-shell nanoparticles in the presence of cationic surfactant.

We developed a novel sensor using carbon paste electrode (CPE) modified with cationic surfactant cetyltrimethylammonium bromide (CTAB) and the core-shell nanoparticles (NPs) of zinc oxide at copper (ZnO@Cu) to study an electrochemical behavior of 2, 4 - dichlorophenol (2, 4 - DCP), a harmful molecule. The core-shell ZnO@Cu NPs/CTAB/CPE is proved to be sensitive because of its sensing features for 2, 4-DCP. The sensor showed excellent electro-catalytic behavior and elevation in peak current in the presence of phosphate buffer solution (PBS) of 0.2 M strength. Advanced techniques like transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDS), and scanning electron microscope (SEM) were employed to ZnO@Cu core-shell NPs characterization. The cyclic voltammetry (CV), as well as square wave voltammetry (SWV) techniques, were applied to study electro-kinetic parameters, including specific heterogeneous rate constant, charge transfer coefficient, accumulation time, scan rate, the effect of temperature, pH, the energy of activation, enthalpy, entropy, Gibb's free energy, and the number of electrons transferred in the 2, 4 - DCP electro-oxidation. By SWV technique, the 2, 4 - DCP molecule was analyzed in vegetables, fruits, water, and soil samples. • The core-shell ZnO @ Cu nanoparticles along with CTAB were used to detect 2, 4-DCP. • The adsorption mechanism was in favour of monitoring an electrochemical process. • The irreversible electrochemical process involved two-electron transfer. • A detection limit value of 2, 4-DCP is 0.227 nM. [ABSTRACT FROM AUTHOR]