Fabrication of electrochemical sensor based on MnO2 nanorods for tetracycline detection

Abstract

ABSTRACT A highly efficient, green and simple method has been reported, for the detection of tetracycline at μM level. An improved redox co-precipitation method was used to make highly MnO2 nanorods from MnCl2.4 H2O and KMnO4. High-resolution transmission electron microscopy (HRTEM) analysis, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett Teller (BET) surface area analysis were used to describe the structure and morphology of the material. The MnO2 material was amorphous and mesoporous, with a surface area of 89.908 m2/g and an average pore size of 6.023 nm. The oxidising property of the produced nano MnO2, as well as its porosity and surface area, have rendered the MnO2 material a potent sensor for tetracycline hydrochloride (TC) detection in an aqueous medium at room temperature. The effect of pH, MnO2 dosage of TC was more favourable at pH 5. The sensor has good electrochemical performance, with a linear response for TC concentration varying from 1 μM to 1 mM and a Limit of Detection (LOD) of 0.513 µM. Furthermore, the prepared sensor exhibited excellent repeatability, portability, reproducibility, specificity, sensitivity and was cost-effective, all of which were the characteristics of a good electrochemical sensor material. The synthesised sensor was employed to determine TC in real-world samples (water and food) to demonstrate its capabilities.