Dopamine-Imprinted Polymers: Template-Monomer Interactions, Analysis of Template Removal and Application to Solid Phase Extraction

Abstract

A dopamine-imprinted polymer (MIP) was prepared in aqueous methanol solution at 60 o C by free-radical cross-linking polymerization of methacrylic acid in the presence of ethylene glycol dimethacrylate as the cross-linker and dopamine hydrochloride as the template molecule. Its ability to isolate dopamine was evaluated as the basis of a solid phase extraction procedure and compared with that of a non-imprinted polymer (NIP). The binding of dopamine was 84.1% and 29.1% for MIP and NIP, respectively. Various reported post-polymerization treatments to reduce template bleeding were examined. In our case the lowest bleeding was achieved after applying a combined procedure: continuous extraction in a Soxhlet apparatus (CE), followed by microwaveassisted extraction (ME) to a level of 0.061 μg/mL. A simplified model of the templatemonomer complexes allowed rationalization of monomer choice based on the heats of complex formation at a PM3 level of theory.

Molecularly imprinted hydrogels for application in aqueous environment

“…Tyramine (4-(2-aminoethyl)phenol) in contrast to dopamine molecule (4-(2-aminoethyl)benzene-1,2-diol) is not substituted by second hydroxyl group, and it was rather suspected that tyramine would posses high-binding affinity to the binding sites created by dopamine in hydrogels, especially that hydroxyl group at second position of the dopamine probably does not participate in binding template to functional monomer process, because no change in chemical shift was observed for proton signal of this hydroxyl group. The similar conclusions were found by Luliński group on the basis of modelling interactions by the HyperChem program in dopamine cation with methacrylic acid or acrylonitryle complexes [12]. Reduced template to functional monomers molar ratio did not bring enhanced effectiveness and selectivity in dopamine rebinding process.…”

“…Modelling of molecular interactions of the templates with functional monomers is sometimes studied in order to preselect the functional monomers used in the synthesis of MIP. Theoretical analysis of the intermolecular interactions in the prepolymerization complexes between dopamine hydrochloride and functional monomers in different solvent was reported by Luliński et al [12]. Investigations of template-functional monomer complexation by 1 H NMR are also informative and give insights at stoichiometry and association strength of the prepolymerization complexes.…”

“…Determination of some catecholamines as well as their metabolites from biological fluids is important in the diagnosis of catecholamine-secreting tumours such as pheochromocytomas, paragangliomas and neuroblastomas [10]. Dopamineimprinted polymers have been studied earlier by the Sugimoto [11], Suedee [7] and Luliński [12] groups, where N-isopropylacrylamide-acrylic acid and acrylamide-methacrylic acid thermosensitive hydrogels, or not thermosensitive ones based on methacrylic acid, were tested, respectively.…”

Theoretical and Computational Strategies for the Study of the Molecular Imprinting Process and Polymer Performance

“…The use of binding energies obtained from calculations on complexes between the template and a set of different functional monomers has become a more frequently used strategy for choosing functional monomers. This approach was adopted by Luliński et al [25] in the design of a dopamine-imprinted polymer system using a PM3 level of theory. Similarly, an AM1 level of theory was used to design a MIP selective for N,O-dibenzylcarbamate [26], as was the case for studies using theophylline as template [27] in conjunction with the more sophisticated B3LYP/6-31+G**//B3LYP/3-21G level of theory.…”

Simultaneous Determination of Dopamine and Ascorbic Acid Using the Nano‐Gold Self‐Assembled Glassy Carbon Electrode

“…Abnormal DA levels suggest an infective symptom of diseases such as HIV infection, schizophrenia, and Parkinsons disease, among others [5,6]. Until recently, some methods have been reported to monitor DA include spectrophotometry [7], high performance liquid chromatography (HPLC) [8], ion chromatography [9], and molecularly imprinted polymers [10,11]. However, these nonelectrochemical methods require expensive equipment or complicated and timeconsuming pretreatment procedures.…”