Artificial Receptor Layer for Herbicide Detection Based on Electrosynthesized Molecular Imprinting Technique and Capacitive Transduction

Abstract

A new artificial receptor layer was successfully electrosynthesized on the gold electrode to fabricate a chemosensor. Based on the molecular imprinting technique and capacitive transduction, the sensor was applied for herbicide detection. The dielectric property of the receptor layer was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The relative capacitive shift depended on the concentration of mefenacet at the range of 1–50 µM. The kinetic aspects of the recognition process were evaluated. A two‐step kinetic model was derived to describe the recognition process. Fitted results were well in agreement with the corresponding experimental results. The selectivity was evaluated by capacitance selective coefficient of mefenacet and other herbicides. The chemosensor exhibited a selective response to herbicide mefenacet. The nonimprinted polymer modified electrode did not show selective response to mefenacet, thus, indicating that the imprinted polymer acts as recognition element of mefenacet sensor.

Keywords:

• Artificial receptor layer
• Capacitive transduction
• Herbicide
• Molecularly imprinted polymer

Acknowledgments

The work was supported by Doctorate Fund (no. 20020532007) and by the Key Sci./Tech. Res. (no. 03123) of Education Department, China.