Preparation of an Electrochemical Sensor for Determination of Chlortetracycline Based on Molecularly Imprinted Film

An electrochemical sensor has been developed for the selective determination of chlortetracycline (CTC) using the molecularly imprinted technique. A molecular imprinted polymer (MIP) on the surface of a glassy carbon electrode (GCE) was prepared by electropolymerization of o-aminophenol (OAP) in the presence of CTC in the sodium perchlorate (NaClO4) solution using cyclic voltammetry (CV). The electrochemical performance of the sensor was studied by using differential pulse voltammetry (DPV). A linear relationship between the peak current difference and the CTC concentration was found in the range of 2.0x10(-8)-6.1x10(-7) mol/L with the detection limit of 1.5x10(-8) mol/L (3 sigma). After regeneration by washing with the mixture of methanol and sulfuric acid, the sensor showed excellent reproducibility and good stability. The MIP electrode exhibited almost no response to chloramphenicol and penicillin, and very weak responses to tetracycline and oxytetracycline, proving a good selectivity. Recoveries of standard addition measured in the actual samples of milk and chicken meat were between 86. 4% - 96. 9%. Compared with the reported methods, this sensor showed a low detection limit, simple operation without derivatization, rapid response and low cost.