Construction and Application of Molecularly Imprinted Film Sensor on Determination of Chlorpyrifos in Water

Molecularly imprinted microspheres for recognition of chlorpyrifos were prepared by thermal initiation and precipitation polymerization, and were characterized using scanning electron microscope and infrared spectroscopy. Binding characteristics of the microspheres were also investigated. Sensitive film electrode of chlorpyrifos was prepared using the microspheres above on the surface of gold electrode by spin coating. Electrochemical sensor was constructed with the electrode prepared above as recognition element, and the response characteristics of the sensor to chlorpyrifos in water were investigated based on constant-current potentiometry. It was shown that a reasonable linear response curve between potential and concentration was obtained from 1.0×10-12mol/L to 2.0×10-8mol/L, with a detection limit of 1.0×10-13mol/L. The suitable pH was 2.2~3.4,and response time was 10 min. The imprinted electrode showed relatively high selectivity to chlorpyrifos and was applied to the analysis of chlorpyrifos in the simulated river samples with recovery rates ranging from 89% to 105%.