A single-use, disposable iridium-modified electrochemical biosensor for fructosyl valine for the glycoslated hemoglobin detection

A single-use, disposable biosensor prototype of fructosyl valine (FV) was developed in this study. FV was a model compound for the glycosylated hemoglobin (HbA_1c) detection and the measurement of HbA_1c level was important for the long-term management of diabetic patients. Therefore, the detection of FV would be important for diabetic patient management as a means for HbA_1c biosensing, particularly if this biosensor could be a single-use, disposable and manufactured cost effectively. This single-use, disposable FV electrochemical biosensor was fabricated using thick film screen-printing technique. Iridium nano-particle catalysts were incorporated in the carbon-based working and counter electrodes enhancing the performance of the biosensor for the FV detection. The enzyme fructosyl amine oxidase (FAO, EC 1.5.3, 0.45 U mg^-1 of solid from recombinant Escherichia coli) was immobilized on the working electrode of the biosensor prototype. This biosensor operated at a relatively low electrochemical potential (+0.25 V versus Ag/AgCl) at ambient temperature to detect the enzymatically produced H₂O₂ from FV. This biosensor responded well to the FV level in a physiological range and the sensor output could be modeled by the Michaelis-Menton relationship. Thus, this biosensor prototype could be used effectively as the basis for a single-use, disposable HbA_1c detection for diabetic patient management.