Effect of minimizing amount of template by addition of macromolecular crowding agent on preparation of molecularly imprinted monolith

Abstract

One of the main challenges in the preparation of molecularly imprinted polymers (MIPs) is the substantial initial amount of template needed because of the requirement of high load capacities for most applications. A new strategy of macromolecular crowding was suggested to solve this problem by reducing the amount of template in the polymerization recipe. In a ternary porogenic system of polystyrene (PS) (crowding agent), tetrahydrofuran, and toluene, an imprinted monolithic column with high porosity and good permeability was synthesized using a mixture of ellagic acid (template), acrylamide, and ethylene glycol dimethacrylate. The effect of polymerization factors, including monomer-template molar ratio and the molecular weight and concentration of PS, on the imprinting effect of the resulting MIP monoliths was systematically investigated. At a high ratio of monomer-template (120:1), the greatest imprinting factor of 32.4 was obtained on the MIP monolith with the aid of macromolecular crowding agent. The PS-based imprinted monolith had imprinting even at the extremely high ratio of functional monomer to template of 1510:1. Furthermore, an off-line solid-phase extraction based on the ground MIP was conducted, and the purification recovery of ellagic acid from pomegranate-rind extract was up to 80 %. In conclusion, this approach based on macromolecular crowding is simple, and is especially valuable for those applications of MIP preparation for which a rare template is used.

Cost‐effective imprinting combining macromolecular crowding and a dummy template for the fast purification of punicalagin from pomegranate husk extract

“…Recently, macromolecular crowding effect was found to be able to minimize the consumption of the template molecule, in imprinting procedure without obvious loss of imprinting effect . In the present study, this effect was demonstrated again.…”

“…In contrast, imprinted polymer synthesized without crowding agent, did not show any imprinting effect at so low template amount (P2, IF = 0.26), suggesting that the dramatic improvement of imprinting effect had been derived from the addition of crowding agent in the polymerization system (Supporting Information Table S1). Normally, imprinting effect decreased rapidly with decreasing the consumption of template, which could be attributed to the left‐shift of equilibrium in template and monomer after reducing the template . Prepolymerization composed of template and monomer with a lower ratio of 1:1564 was prepared and then initiated to form a MIP (P3).…”

“…The crude pomegranate extract were prepared using the method presented in the earlier work . 5.0 mg of the crude pomegranate extract was dissolved in acetonitrile/sodium acetate (pH 3.6, 200 mM) (93:7, v/v) and filtered, and then loaded into the SPE column and went through the optimum SPE procedure obtained in Section .…”

“…A protocol based on a biological concept named “macromolecular crowding” was expected to provide an approach for solving these problems . In a living system such as biological cell, biological macromolecules like lipids, nucleic acids, and proteins often cause “crowding” environment, which could effectively affect the stability of high‐order structures of biopolymers and promote the association of biomolecules.…”

Effect of polyethylene glycol as a molecular crowding agent on reducing template consumption for preparation of molecularly imprinted polymers

“…Using a high concentration of linear polymer, the formation of hydrogen bonds between the template and the monomer at the pre-polymerization stage is promoted, and thus the resultant polymers have a superior affinity or number of binding sites for the template. Although a number of crowding-assisted MIPs have been successfully developed, such as MIP monoliths [14][15][16][17][18] and microparticles, [19][20][21] the molecular crowding agents used in the literature are limited to polystyrene (PS) 14,19 and methyl methacrylate (PMMA). 13 Recently, an effect of minimizing the amount of template by addition of macromolecular crowding agents on preparation of the imprinted monolith was observed.…”