A robust and practically free of charge intermittent use glucose biosensor

In the past decades, great effort has been put in finding new electrode surface modifiers and enzyme immobilizer agents that prevent the enzyme leakage, minimize the effect of interfering species, retain the enzyme bioactivity, and enhance the sensor sensitivity. In this work, a sandwich-type glucose biosensor that keeps its sensitivity and operational linear range for more than a year is presented. After 5 months of intermittent use, where the biosensor was exposed to more than 500 standard additions, it presented a limit of detection of 5 mu M, and the linear behavior was from 5 mu M to 3 mM with a value of r(2) = 0.999. Besides, after 7 months of its assembling, the biosensor was employed for assessing the glucose concentration of real serum samples and its performance was compared with the response of a commercial autoanalyzer. A year later, the biosensor still exhibited very good performance of its analytical parameters. The performance of identical sandwich-type biosensors is analyzed when they are exposed to three different storage conditions. Simulated curves are compared with experimental data to explain the dependence of sensitivity and response-time on the aging and storage conditions of the biosensors. (C) 2017 Elsevier B.V. All rights reserved.