Flexible, Bifunctional Sensing Platform Made with Biodegradable Mats for Detecting Glucose in Urine

Abstract

We report on a flexible, bifunctional platform made with solution-blow spinning fiber mats of polylactic acid (PLA) and polyethylene glycol (PEG). The PLA/PEG mats were designated bifunctional because they were used as a substrate for screen-printed carbon electrodes (SPCEs) and as a matrix to attach glucose oxidase (GOx) covalently. By attaching GOx only on the fiber mats, and not on the SPCE, the detection of hydrogen peroxide generated from glucose oxidation by the enzyme was efficient, especially with Prussian blue (PB) nanoparticles electrodeposited on the SPCE surface. The bifunctional device detected hydrogen peroxide (H2O2) in synthetic and human urine at a low applied potential (0 V vs Ag/AgCl) in the range from 1.0 to 6.0 mM, with a detection limit of 0.197 mM, being also interference-free. The biosensor whose cost is <US$ 0.25 per unit (estimated from the price of the materials used) had performance comparable to the gold standard method while measuring glucose in human urine samples, in addition to exhibiting a rapid response and long lifetime. The design of the bifunctional device is generic and may be extended to other biosensors for on-site monitoring as well as for wearable devices and in monitoring the environment and water in varied resources.