Electrochemical detection of chloramphenicol residues in milk samples using a working electrode modified with Fe3O4 superparamagnetic nanoparticles

Abstract

Antibiotic residues in food, particularly in agricultural and aquaculture products, have become a serious issue requiring effective solutions in Vietnam. This problem is largely attributed to the excessive use of antibiotics in livestock farming, which not only poses risks to public health but also negatively affects the reputation and commercial value of exported products. In this context, electrochemical sensors have been recognised as a potential technological solution due to their advantages, including simple fabrication, low analytical cost, quick response, and high sensitivity and selectivity. In this study, Fe₃O₄ superparamagnetic nanoparticles, characterised by high electron conductivity, low toxicity, good biocompatibility, and strong adsorption capacity for organic compounds such as antibiotics, were used to modify the working electrode of commercial C110 electrochemical sensors (Metrohm, Switzerland) in order to enhance the electrochemical signal and improve sensor sensitivity. The results showed that the electrochemical sensor detected chloramphenicol (CAP) in phosphate buffer solution (PBS) with a low limit of detection (LOD) of 0.06 μM, a relative standard deviation (RSD) of below 5%, and a recovery rate of 94.77%. The sensor was applied for the rapid determination of CAP residues in milk samples at a concentration of 1 μM, achieving recovery rates of 95-109%
and a relative standard deviation of 2.14%. These promising findings serve as a foundation for further research to develop label-free, portable electrochemical sensors for on-site analysis, contributing to food safety monitoring and the protection of consumer health in Vietnam.