Fabrication and application of functionalized carbon nanotubes for highly sensitive and selective sensing of enrofloxacin

Abstract

This paper introduces an innovative electrochemical sensor that detects enrofloxacin (ENR) utilizing a glassy carbon electrode (GCE) modified with reduced carbon nanotubes (rCNT). The fabrication process involved a simple drop‐coating technique using water‐soluble oxidized CNTs (oCNT), followed by electrochemical reduction to obtain the rCNT/GCE electrode. The electrochemical properties of the modified electrodes, including GCE, CNT/GCE, oCNT/GCE, and rCNT/GCE, were evaluated using cyclic voltammetry and electrochemical impedance spectroscopy. The results demonstrated significantly improved electrochemical surface area and faster electron transfer rate for the rCNT/GCE electrode compared to the other configurations. Consequently, the rCNT/GCE electrode exhibited the highest electrochemical signal for ENR detection. Under optimized conditions, the rCNT/GCE‐based sensor displayed excellent performance for ENR detection. It achieved a low detection limit of 0.002 µm and demonstrated linearity within the ranges of 0.005–0.05 µm and 0.05–1.5 µm. Furthermore, the proposed sensor exhibited good selectivity, as well as excellent repeatability and reproducibility. To assess the sensor's practical utility, a quantitative analysis of ENR in shrimp meat samples was conducted. The results demonstrated the high sensitivity and accuracy of the proposed sensor in quantifying ENR, highlighting its potential as a reliable tool for environmental monitoring of water resources.