Abstract:The serious impact of the improper use of antibiotics in food-related fields such as animal husbandry and fishery on the environment and human body has attracted widespread attention of many researchers. In this study, a magnetic beads-kanamycin complex was prepared, and a simple, rapid and sensitive competitive colorimetric aptamer sensing strategy was developed by competing for the aptamer in the system between kanamycin on the surface of magnetic beads and kanamycin in the sample. The synthesis of magnetic beads-kanamycin and the biological recognition between the aptamer and the target were characterized by scanning electron microscope and ultraviolet-visible spectrophotometer. The successful synthesis and recognition provide a strong guarantee for the sensing strategy construction. The sensor has good colorimetric performance in the detection range of kanamycin molar concentration of 0.05~500 nmol/L, and the limit of detection is 0.21 nmol/L. In addition, by comparing with other aminoglycoside antibiotics detection experiment, it could be concluded that the sensor has a good selectivity to kanamycin. In short, the colorimetric aptasensor is easy to operate without large-scale instruments, providing a good idea for the rapid detection of other antibiotics and other chemical contaminants affecting food safety.
