A study on fast detection methods for tetracycline antibiotic residues based on magnetic nanoparticles and electrochemical aptasensors

This study presents the development of novel electrochemical aptasensors utilizing magnetic nanomaterials for rapid and sensitive detection of tetracycline (TET) antibiotic residues. Two types of nanocomposites, Cu 2 O@Au octahedral nanoparticles and rGO-Fe 3 O 4 , were synthesized and characterized for aptasensor fabrication. The Cu 2 O@Au-based aptasensor demonstrated a linear detection range from 1 nM to 1 μM, with a limit of detection (LOD) of 0.3 nM. The rGO-Fe 3 O 4 /sodium alginate-based aptasensor exhibited a linear range of 5 nM to 500 nM, with an LOD of 1.5 nM. Both aptasensors showed excellent specificity towards TET, good reproducibility (RSD < 5.6 %), and stability (>90 % response after 2 weeks). The practical applicability of the aptasensors was validated through TET detection in spiked milk samples, achieving recoveries between 88.6 % and 107.8 % with RSDs below 7.2 %. These aptasensors offer advantages such as rapid response, simple fabrication, and potential for on-site detection, making them promising tools for food safety monitoring and environmental surveillance.