| Abstract
| - The aim of this investigation was to determine whether relatively weak interactions, such as hydrogenbonds to aromatic chlorine atoms and interactions involving aromatic π electrons could be exploited withinartificial receptors, constructed using the technique of molecular imprinting. For the purposes of this investigationwe chose 2,3,7,8-tetrachlorodibenzodioxin (TCDD) as the model target. Imprinted polymers have been preparedwith two new templates designed to create recognition sites for TCDD. The first of these, the bis-N-(4-vinylphenyl)urea derivative of 2,8-dichloro-3,7-diaminodibenzodioxin, employed a carbonyl spacer to introducearomatic amines into the polymer after reductive cleavage of the template. The second, N-(2-(3,7,8-trichlorodibenzodioxinyl))-2-methacryloyloxybenzamide, incorporated a salicylic acid spacer and introduceda methacrylic acid residue into the polymer following hydrolysis. Both amine and acid groups were positionedin such a way as to interact with TCDD through the formation of weak hydrogen bonds to aromatic chlorineatoms. A second recognition element was introduced into the binding sites by the inclusion of a polymerizable,electron-rich, aromatic ether capable of forming π−π interactions with the electron-deficient dioxin molecule.Polymers imprinted with either template showed significantly higher uptake of TCDD than the correspondingnonimprinted controls, even at concentrations as low as 2 nM.
|
