In this work, a simple and sensitive electrochemical method was developed to determine ethyl violet (EV) dye in aqueous systems by using square wave anodic stripping voltammetry (SWASV) employing a glassy carbon electrode modified with acidic-functionalized carbon nanotubes (COOH- f CNTs). In square wave anodic stripping voltammetry, EV exhibited a well-defined oxidation peak at 0.86 V at the modified GCE. Impedance spectroscopy and cyclic voltammetry were used to examine the charge transduction and sensing capabilities of the modified electrode. The influence of pH, deposition potential, and accumulation time on the electro-oxidation of EV was optimized. Under the optimum experimental conditions, the limit of detection with a value of 0.36 nM demonstrates high sensitivity of COOH- f CNTs/GCE for EV. After detection, it was envisioned to devise a method for the efficient removal of EV from an aqueous system. In this regard a photocatalytic degradation method of EV using Ho/TiO 2 nanoparticles was developed. The Ho/TiO 2 nanoparticles synthesized by the sol–gel method were characterized by UV–vis, XRD, FTIR, SEM, and EDX. The photocatalytic degradation studies revealed that basic medium is more suitable for a higher degradation rate of EV than acidic and neutral media. The photodegradation kinetic parameters were evaluated using UV–vis spectroscopic and electrochemical methods. The results revealed that the degradation process of EV follows first-order kinetics.

The presence of organic pollutants in water and food samples is a risk for the environment.

The discharge of dye loaded effluents from textile and food industries into natural water has skyrocketed in the last few years due to booming industrialization needed to serve a mushrooming population. The adulterated water poses a serious threat to human and aquatic life. The present work aims to engage electrochemical methods by designing an electrochemical sensor using a modified glassy carbon electrode with amine functionalized multi-walled carbon nanotubes (NH2-fMWCNTs) to detect nanomolar concentration of Metanil Yellow (MY) which is an azo dye used illegally in food industry. Various experimental conditions, such as the supporting electrolyte, pH of the electrolyte, deposition potential, and deposition time were optimized for the best performance of the designed sensing platform by square wave anodic stripping voltammetry (SWASV). Under optimized conditions, the limit of detection of MY was found to be 0.17 nM. The catalytic degradation of the dye was also probed by the designed nanosensor electrochemically and the results were supported by UV-visible spectroscopic technique. The dye was found to follow pseudo first order kinetics with a degradation extent of 98.7 %. The obtained results hold great promise for safeguarding human and aquatic lives from the effects of toxic dye effluents.