Selective Recognition of the Herbicide Atrazine by Noncovalent Molecularly Imprinted Polymers

Abstract

Molecular imprinting was applied to the synthesis of methacrylic acid-ethylene glycol dimethacrylate copolymers specific for the herbicide atrazine. In toluene, these imprints bound atrazine with dissociation constant (K D ) values as low as 10 -6 M, and could be used for the development 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 cross-reactivity, and the binding affinity decreased in the order Cl > OCH 3 > OH > SCH 3 (atrazine, the imprint species, has Cl at this position). No cross-reaction of structurally unrelated herbicides and other compounds was detected. Rebinding experiments in phosphate buffer containing 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 pollutants in environmental analysis and as sorbents for the specific removal of toxic compounds in waste water treatment are discussed.

Molecularly imprinted polymers by reversible addition–fragmentation chain transfer precipitation polymerization for preconcentration of atrazine in food matrices

“…For RAFT-MIP1, K d and Q max were calculated to be 0.0136 mg L −1 and 2.89 mg g −1 , respectively, whereas the values for TR-MIPs were 0.026 mg L −1 and 1.53 mg g −1 , respectively, which was consistent with the experimental observation. However, the K d value was different from the old paper by Mosbach's group (10 −6 M) [25] and Takeuchi's group (12 M) [31]. Perhaps, this phenomenon can be explained as follows: (1) the preparation methods were different.…”

“…mental results [24,25]: MAA displayed the best effectiveness as functional monomer when used to imprinting atrazine because they can form double hydrogen bond with atrazine, which leads to an understanding that a functional monomer is required to have both strong binding and multiple binding capacity.…”

“…For NIPs, the nonspecific binding is higher for more polar compounds. This phenomenon can be attributed to the presence of carboxylic acid groups on the polymer surface, which can be involved in hydrogen bonding with polar molecules [25]. The recognition mechanism could be explained as follow: in preparation process, many specific recognition sites with respect to template were generated in imprinted polymers, so the template could strongly bound to the polymers in binding process.…”

From 3D to 2D: A Review of the Molecular Imprinting of Proteins

“…Commonly these systems have utilized polar noncovalent interactions to establish polymer-template reciprocal functionality on which MIP function relies. Examples of this type of strategy includes amino acids (21), drugs such as theophylline and diazepam (22), nucleotides (23), and pesticides (24). An alternative approach relies initially on covalent interactions to establish reciprocal functionality, while subsequent rebinding has been demonstrated through either the re-establishment of covalent linkages or via a noncovalent mechanism (25).…”

Design and Preparation of Molecularly Imprinted Atrazine-Receptor Polymers: Investigation of Functional Monomers and Solvents

“…1,2 The polymer receptor exhibited a dissociation constant of 10 -5 M and excellent selectivity to atrazine. Two other independent groups also reported on atrazine-imprinted polymers prepared by a similar procedure 3,4 , where radio-ligand assay was demonstrated using atrazine-imprinted polymers as reagents alternative to antibodies. As another application of a molecularly imprinted polymer, solid phase extraction using an atrazine-imprinted polymer has been reported.…”