Development of a flow-injection analysis (FIA) enzyme sensor for fructosyl amine monitoring

Abstract

An enzyme-sensor system with flow-injection analysis (FIA) has been developed for the detection of fructosyl amine compounds; the sensor utilizes fructosyl amine oxidase isolated from the marine yeast Pichia sp. N1-1 strain. With this FIA system 0.2 to 10 mmol L(-1) fructosyl valine can be determined. The sensor is approximately five times more sensitive to fructosyl valine, a model compound for glycated hemoglobin HbA1c, than to N(epsilon)-fructosyl lysine, a model compound for glycated albumin. This FIA system can also be used to detect fructosyl dipeptides. The operational stability of the sensor enabled more than 120 consecutive sample injections over a period of approximately 20 h.

Determination of Fructosyl Amino Acids and Fructosyl Peptides in Protease-digested Blood Sample by a Flow-Injection System with an Enzyme Reactor

“…This selectivity for FV differs from that obtained by FAO from the marine yeast Picha sp. N1-1 strain, reported by Ogawa et al 24 The FPOX-CE and FPOX-CET reactors showed the maximum activities for both FV and FVH at pH values around neutrality. Therefore, the FAOX-TE reactor was operated at pH 8.0, while the FPOX-CE and FPOX-CET reactors were operated at pH 7.0 throughout this work.…”

“…Though the characteristics of the FPOX-CET reactor were similar to those of FPOX-CE in the optimum pH and the substrate specificity, the FPOX-CET reactor had a higher thermostability than the FPOX-CE reactor. All of three immobilized enzyme reactors were more stable than the FAO immobilized sensor reported by Ogawa et al 24 When three enzyme reactors were stored at 4˚C in optimum buffer, they retained most of their activities for 90 days. Thus the storage stability was good for three enzyme reactors.…”

“…The lowest concentrations which could be detected were 6.7 μM for the former system and 4.0 μM for the latter system, respectively, when the signal to noise ratio was 3. The proposed FIA systems with enzyme reactors were highly sensitive compared to the insufficient detection limit (0.2 mM) of the FV sensor reported by Ogawa et al 24 The reproducibility of the measurements for the FIA system with the FPOX-CET reactor was 2.5% (n = 16) for 11.6 μM FV and 0.62% (n = 16) for 58.6 μM FV, respectively. It is known that the physiological HbA1c level in blood is 4 to 15% of total hemoglobin (80 -200 g l -1 ).…”

“…Ogawa et al 24 also reported a flow-type fructosyl valine sensor constructed by immobilizing FAO onto a platinum electrode. However, the sensor sensitivity was insufficient for the detection of fructosyl valine released from glycohemoglobin in blood by the protease and the operational stability of the sensor was not good.…”

A Nonenzymatic Amperometric Method for Fructosyl‐Valine Sensing Using Ferroceneboronic Acid

“…Until recently, most Fru-Val electrochemical sensors have followed the work of Sodes group and employed fructosyl amine oxidase (FAO) [6]; such an approach has allowed the fabrication of an FAO based electrode for Fru-Val sensing that directly detects hydrogen peroxide from the enzyme-catalyzed reaction. Given that enzymes are inherently temperature sensitive and labile, a nonenzymatic electrochemical means of detecting this key marker of disease progression represents a new and significant diagnostic advance.…”