Low-potential Electrochemical Sensor based on Hollow Molybdenum Carbide/Carbon Spheres for Detection of Oxytetracycline in Tap Water and Milk

Abstract

Accurate and rapid detection of oxytetracycline (OTC) in real samples, which is one of the most used and typical tetracycline antibiotics, is of crucial importance for protecting ecological health and supporting effective environmental monitoring. However, achieving free-interference and detection of OTC is a formidable challenge. Herein, a high-performance and low potential electrochemical sensor (Mo2C/GCE) based on hollow molybdenum carbide (Mo2C)/carbon spheres modified glassy carbon electrode (GCE) is reported to achieve free-interference, accurate for detection of OTC. The hollow Mo2C/carbon spheres not only exhibited enzyme like activity, along with a significantly higher specific surface area and a greater density of accessible active sites compared to conventional two-dimensional carbon-based materials. In addition, Mo2C was subjected to high potential oxidation during electrocatalysis, resulting in the formation of numerous surface defects and carbonyl functional groups on its carbon material surface. These defects and carboxyl groups provide more electrochemical active sites and reduce the oxidation overpotential of OTC, facilitating the interface electron transfer. Thus, the electrochemical oxidation potential of OTC on Mo2C/GCE decreased from 0.78 V to 0.64 V compared with the GCE. Mo2C/GCE for the detection of OTC using amperometry analysis exhibited a wide linear range of 0.01∼2000 μM as well as a low limit of detection (LOD) of 0.01 μM. Ultimately, the developed sensor was demonstrated for measurement of OTC in tap water and milk at low potential. Considering the excellent analytical performance and of the prepared electrochemical sensor, its potential for detection of OTC in environmental monitoring and public health, is demonstrated.