Magnetic nanoparticles-based electrochemical aptasensor for the detection of enrofloxacin in chicken

Enrofloxacin (ENR) is widely applied in preventing and treating animal diseases and hence directly passed into animal-derived foods. Therefore, the detection of this drug in food samples must be strengthened to ensure food safety. In this work, a simple, sensitive electrochemical aptasensor for the detection of ENR was fabricated by using magnetic nanoparticles (MNPs) as carriers. The ENR aptamer was modified on the surface of MNPs to capture the ENR target or a biotin-complementary strand and then recognize streptavidin-horse radish peroxidase. Subsequently, the resulting MNPs were easily transferred onto the surface of magnetic glassy carbon electrode with the help of its integral magnet. Under optimal experimental conditions, a linear relationship between the variable of LSV current and the logarithm of ENR concentration in the range of 0.01-100 ng/mL was obtained with the limit of detection at 4.9 pg/mL. In addition, this method exhibited good stability, selectivity, reproducibility and was successfully applied in detecting ENR in spiked chicken samples with recoveries of 100.70%-108.96%. The proposed method is easy to fabricate and process; it is particularly suitable for food sample pretreatment and is beneficial in removing the interference of a complex matrix.