Construction of a molecular imprinting catalyst using target analogue template and its application for an...

Molecular imprinting technology is becoming a versatile tool for preparing tailor-made molecular recognition elements. However, inherent problems of the molecular imprinting technology include the availability and preparation of template molecules. We recently reported artificial enzyme sensors for fructosylamines constructed by imprinting with fructosyl valine (Fru-val), a model compound for HbA1c (Anal. Lett., 2003). However, because the availability of Fru-val is limited, we attempted to construct a Fru-val-oxidizing molecularly imprinted catalyst (MIC) utilizing the analogue molecule methyl valine (m-val) as template molecule. An electrode employing the m-val-imprinted polymer showed 1.2-fold higher sensitivity toward Fru-val compared with the control polymer-employing electrode. We also used the positively charged functional monomer allylamine as functional monomer in order to increase the selectivity of the MIC toward Fru-val. The selectivity of the electrode immobilizing the allylamine-containing polymer showed 1.7-fold higher response toward Fru-val than toward Fru-epsilon-lys. By combining the use of both allylamine as the functional monomer and m-val as the template molecule, an even better MIC-immobilized electrode was produced with a Fru-val selectivity comparable to that constructed by imprinting with Fru-val.