Molecular imprinting of fructose using a polymerizable benzoboroxole: Effective complexation at pH 7.4

Covalent molecularly imprinted polymers against d-fructose employing 5-methacrylamido-2-hydroxymethylphenylboronic acid as functional monomer and trimethylpropane trimethacrylate (TRIM) as the crosslinking agent were prepared by a conventional radical bulk polymerization (MIP-BX(Fru)). Batch binding studies for fructose in aqueous buffers containing 10% methanol revealed that the binding capability of MIP-BX(Fru) is paramount compared to a MIP prepared with vinylphenylboronic acid MIP-BA(Fru). Especially, at the biological important pH-value of 7.4 the rebinding of fructose to the MIP-BX(Fru) is with 60 nmol per mg polymer about 3.2 higher compared to the MIP-BA(Fru). A pinacol imprinted polymer was also investigated and showed in case of MIP-BX still an imprinting of 1.7 at pH 7.4 whereas MIP-BA did not show a difference. Cross-reactivity studies at pH 7.4 show the shape-selectivity of the MIP-BX(Fru) in the order of l-fructose, sorbitol, glucose and sucrose.