Amperometric detection of glucose in fruit juices with polypyrrole-based biosensor with an integrated permselective layer for exclusion of interferences

•Bilayer glucose biosensor with permselective layer for interference reduction.•Rejects interferences from ascorbic acid, glycine, glutamic acid and uric acid.•Highly stable reponse for more than 2 months.•Wide linear range of 0.5-24 mM and a detection limit of 26.9 μM.•Enabled reliable glucose determination in fruit juices and non-alcoholic beverages.

A novel polypyrrole (PPy)-based bilayer amperometric glucose biosensor integrated with a permselective layer has been developed for detection of glucose in the presence of interferences. It comprises of a PPy-GOx film grown, in the absence of electrolyte, as an inner layer, and a permselective PPy-Cl film as an outer layer. The PPy-GOx/PPy-Cl bilayer biosensor was effective in rejecting 98% of ascorbic acid and 100% of glycine, glutamic acid and uric acid. With an outer layer thickness of 6.6 nm, the bilayer biosensor gave nearly identical glucose response to that of a single layer PPy-GOx biosensor. The biosensor also exhibited good reproducibility (1.9% rsd, n = 10), high stability (more than 2 months), wide linear range (0.5-24 mM), low Km (8.4 mM), high Imax (77.2 μA cm−2), low detection limit (26.9 μM) and good sensitivity (3.5 μA cm−2 mM−1). The bilayer biosensor was successfully employed for glucose determination in various fruit juices.