Sensitive and selective electrochemical characterization and analytical determination of linezolid in environmental samples using TiO2 nanoparticles and MWCNT-COOH modified glassy carbon electrode

Abstract

In this study, a sensitive, selective, and applicable electrochemical method based on the oxidation of linezolid active material was developed using a bare glassy carbon electrode (GCE) and modified glassy carbon electrodes treated with titanium dioxide nanoparticles/carboxyl-function multi-walled carbon nanotubes (TiO2/MWCNT-COOH/GCE). The surface characterization of the developed TiO2/MWCNT-COOH/GCE was examined using scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). The electrochemical properties of the linezolid substance were investigated using cyclic voltammetry. Furthermore, drug determination was carried out by differential pulse voltammetry (DPV) and absorptive stripping differential pulse voltammetry (AdSDPV). The linearity range under optimized conditions was determined as 1–20 µM and 0.2–2.0 µM on the bare GCE and TiO2/MWCNT-COOH modified electrode, respectively. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.0365 µM and 0.1215 µM for bare GCE, and 0.00056 µM and 0.00188 µM for TiO2/MWCNT-COOH/GCE, respectively. Interference studies were also performed by the developed sensor with various inorganic and organic substances that could affect LNZ detection. Then, the proposed sensor was applied for the determination of LNZ in real samples such as soil, tap water, and natural spring water samples, and the accuracy of the proposed method was proven in recovery studies, with values of 99.90 %, 100.94 %, and 101.17 %, respectively. In conclusion, a new sensor with high recovery, low relative error, and high selectivity was successfully produced and applied to detect LNZ in actual samples.