Development of an aptasensor for electrochemical detection of tetracycline

Developing the rapid, simple and sensitive biosensor system for tetracycline detection is very important in food safety. In this paper, we developed a label-free aptasensor for electrochemical detection of tetracycline. The reorganization of tetracycline binding aptamer was confirmed by Isothermal Titration Calorimetry, Kd = 5.18 × 10−5 mol L−1. According to the electrochemical impendence spectroscopy (EIS) analysis, there was a linear relationship between the log concentration of tetracycline and the charge transfer resistance (ΔRet) from 5.0 to 5.0 × 103 ng mL−1 of the tetracycline conc. The detection limit was 1.0 ng mL−1 within a detection time of 15 min. The average of assemble rate Q was at 82.4% with a differential batches' RSD of 4.6%. The current change of this aptasensor lies within at 8.5% after a storage of 15 days under 4 °C. The result aptasensor had shown a good reproducibility with an acceptable stability in tetracycline detection. The recoveries of TET in spiked milk samples were in the range of 90.0-95.7%.