Fabrication of a very sensitive electrochemical sensor for determination of trace amounts of 2,4-dichhlorophenoxyacetic acid in soil and water samples

An indirect and very sensitive electrochemical determination of herbicide 2,4‒ dichlorophenoxyacetic acid was developed based on application of the molecularly imprinted polymer concept and using double stranded deoxyribonucleic acid as a biospecific substance. The sensor was prepared by electropolymerization of ortho-phenylendiamine on a modified pencil graphite electrode with chitosan and multiwall carbon nanotubes in the presence of DNA and also 2,4‒dichlorophenoxyacetic as a template molecule. The current variations the concentration of 2,4‒ dichlorophenoxyacetic in the range of 0.01 to 10 pM and the detection limit was obtained as 0.4×10- 14 M. This method has been successfully applied to the determination of 2,4‒dichlorophenoxyacetic in the environmental water and soil samples with recovery rates ranging from 96% to 113%.