Silver‐Copper Oxide Core‐Shell Nanoparticles/β‐Cyclodextrin Functionalized Single‐Walled Carbon Nanotubes Based Electrochemical Sensor for 4‐Chloro‐3‐Methylphenol Detection

Abstract

Chlorophenols are high‐priority organic pollutants that harm the environment and human health. Therefore, it is crucial and urgent to detect and quantify chlorophenols in the environment selectively and sensitively. For this, the introduction of smart nanomaterials to create electrochemical sensors is a noteworthy development. In the present article, a glassy carbon electrode was fabricated by Agcore‐CuOshell nanoparticles (Ag@CuO) and β‐cyclodextrin functionalized single‐walled carbon nanotubes (β‐CD‐fSWCNT) through drop‐casting method (Ag@CuO‐β‐CD‐fSWCNT‐nafion‐GC) and applied for the selective and sensitive detection of chlorophenols, particularly 4‐chloro‐3‐methylphenol (CMP). The Ag@CuO nanoparticles with core‐shell configuration were synthesized and characterized by using various analytical techniques like UV–vis spectroscopy, X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), high‐resolution transmission electron microscopy (HR‐TEM), selected area electron diffraction pattern (SAED), and energy dispersive X‐ray spectroscopy (EDS). The electrode fabrication steps were monitored and confirmed by using field‐emission scanning electron microscopy (FE‐SEM), attenuated total reflectance – Fourier transform infrared spectroscopy (ATR‐FTIR), and cyclic voltammetry (CV) studies. The electrochemical sensing of CMP was done by using differential pulse voltammetry (DPV) and the results showed that the peak current is linear with increasing concentration in the range of 10–50 µM at the modified electrode. The detection limit of 1.4 nM (S/N = 3) was obtained with a correlation coefficient of 0.998. The electrode showed good reproducibility with a relative standard deviation (RSD) of 1.56% and sensitivity of 15.67 µAcm−2µM−1 toward CMP. The sensor showed anti‐interference properties and long‐term stability. The real sample analysis results indicated that the sensor electrode could be used to detect low concentrations of CMP in wastewater with a recovery of 103.3% and has good potential for use in practical applications.