SELECTIVE RECOGNITION OF THE HERBICIDE ATRAZINE BY NONCOVALENT MOLECULARLY IMPRINTED POLYMERS

Molecular imprinting was applied to the synthesis of methacrylic acid- ethylene glycol dimethacrylate copolymers specific for the herbicide a trazine. In toluene, these imprints bound atrazine with dissociation c onstant (K-D) values as low as 10(-6) M, and could be used for the dev elopment of a ligand binding assay for the detection of atrazine. The selectivity profile of the imprints for triazines structurally related to atrazine was comparable to those of antibodies. The substituent of carbon C1 is the most important feature determining the level of cros s-reactivity, and the binding affinity decreased in the order Cl > OCH 3 > OH > SCH3 (atrazine, the imprint species, has C1 at this position) . No cross-reaction of structurally unrelated herbicides and other com pounds was detected. Rebinding experiments in phosphate buffer contain ing 0.15% Tween 20 gave similar results. The polymers could be packed into HPLC columns and used for the separation of triazine derivatives. The potential uses of imprinted polymers for the detection of polluta nts in environmental analysis and as sorbents for the specific removal of toxic compounds in waste water treatment are discussed.