An Amperometric Sensor Based on Gold Electrode Modified by Soluble Molecularly Imprinted Catalyst for Fructosyl Valine

An amperometric sensor based on a soluble molecularly imprinted catalyst (MIC) has been developed for the detection of fructosyl amine compounds. A soluble MIC containing water-soluble functional monomers, an imidazole catalyst, and small amounts of a hydrophilic cross-linker is developed and used as a fructosyl amine oxidase mimic and for amperometric sensor construction. Fructosyl valine (Fru-val), a model compound of glycated hemoglobin, HbA1c, is used as the template. The MIC specifically oxidizes Fru-val in the presence of 1-methoxyphenazine methosulfate (electron acceptor) and reacts with the glycated peptide, fructosyl-valine-histidine sequence at the N-terminal of the beta-globin in HbA1c. The biosensor was fabricated by immobilizing the soluble MIC on Au electrodes via 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC)-mediated amidation coupling. Using the soluble MIC-based sensor, 0.05 to 0.6 mM Fru-val could be determined at 40 degrees C and neutral pH. The steady-state current increase for this sensor was 33 nA in the presence of 0.05 mM Fru-val. The sensor showed 1.4 times higher sensitivity to Fru-val than to Fru-epsilon-lys, the competitor in HbA1c detection. (C) The Electrochemical Society of Japan, All rights reserved.