Ayat Mohammad‑Razdari, Mahdi Ghasemi‑Varnamkhasti,   Sajad Rostami,  Zahra Izadi,  Ali A. Ensafi

Journal of Food Measurement and Characterization (2021) 15:3387–3396, https://link.springer.com/article/10.1007/s11694-021-00917-7

Abstract : Tetracycline (TET) is one of the most conventional antibiotics with a widespread application in veterinary medicine and livestock like mastitis. Detection of this antibiotic in milk is far important because its presence reduces the dairy products and also can increase the antibiotic resistance in human body. In current study, an electrochemical aptamer-based biosensor was designed for TET residues detection as a sensitive, selective, and rapid way based on a pencil graphite electrode (PGE) using magnetic nanoparticles (MNP) and gold nanoparticles (GNP) composite. The linear concentration range and detection limit values of the aptasensor was obtained as 1.0 pM to 1.0 μM, and 0.03 pM toward TET, which is lower than the value determined as allowable by the European Union (225 nM). A high selectivity for TET was shown by aptasensor over the other antibiotics including Sulfadiazine, Ampicillin, Penicillin G, and Streptomycin. The results of the TET-spiked in milk samples suggested reasonable recoveries between 92 and 102%. As a result, 90 min was the optimization time for aptasensor response. The relative standard deviation (RSD) was obtained as 5.9%, indicating an acceptable reproducibility for the aptasensor. The obtained results showed that the fabricated aptasensor is an efective, selective, and rapid assay for TET detection in milk and food quality control

Keywords Magnetic nanoparticles · Gold nanoparticles · Electrochemical aptasensor · Antibiotic residues · Label-free impedimetric detection