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

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.