Choice of the functional monomer of molecularly imprinted polymers: Does it rely on strong acid-base or hydrogen bonding interactions?

The choice of the functional monomer is a key point in the design of molecularly imprinted polymers (MIPs) because its directional interactions with template molecules are required to form molecular imprints acting as selective recognition sites for adsorption. Methacrylic acid (MAA) has very often been employed as a functional monomer for imprinting basic template molecules. Strong acid-base interactions lead to H+ transfer and weak hydrogen bonding between the products of the acid-base reaction. The weakly acidic acrylamide (AA) has shown stronger hydrogen-bonding interactions with histamine (HA) than MAA. Interactions between HA and the functional monomers have been investigated by means of H-1 NMR spectroscopy yielding the stoichiometry and complexation constants of their complex species. Adsorption isotherms of HA to both MAA- and AA-based MIPs and their modeling showed a higher selective binding of HA to the AA-based MIP.

Automated summary

The choice of functional monomer in molecularly imprinted polymers (MIPs) is crucial for designing selective recognition sites for adsorption. Studies using H-1 NMR spectroscopy revealed that the weakly acidic acrylamide (AA) showed stronger hydrogen-bonding interactions with histamine (HA) compared to methacrylic acid (MAA). Adsorption isotherms and modeling of MIPs demonstrated a higher selective binding of HA to AA-based MIPs.