3D printed electrochemical dual-sensor biodevice for the simultaneous determination of glucose and ethanol in wines

The sustainable and affordable fabrication and direct use of integrated electrochemical biosensors in point of need settings support the decentralization of food and beverage quality monitoring from centralized laboratories. Leveraging the digital simplicity, cost-effectiveness, and laboratory-free advantages of 3D printing, we present a compact, fully integrated, 3D printed dual-sensor enzymatic biodevice for the simultaneous amperometric determination of ethanol (ETH) and glucose (GLU) in wine samples via a single assay using a portable bi-potentiostat. The device was fabricated through a one-step process and comprised four carbon black/polylactic acid (CB/PLA) electrodes—two working electrodes (WEs), one reference, and one counter electrode—embedded in a small biodegradable PLA cell. Each WE was modified with a Prussian Blue mediator layer, the respective oxidase enzyme, and a Nafion film to enable selective biocatalytic oxidation and simultaneous detection of both analytes from a single drop of wine. The developed method exhibited high sensitivity (limits of detection: 0.4 mM ETH and 9.5 μM GLU), excellent selectivity against common interferences, and reproducibility, confirming operational and fabrication robustness. The concentrations of ETH and GLU in three wine samples were determined and validated against standard chromatographic methods. The device can be easily produced at the point of need, and the results demonstrate its ability for rapid, direct, sensitive, and selective on-site simultaneous measurements of ETH and GLU in wines, while also offering prospects for extension to the monitoring of other chemical markers relevant to the food and beverage industry.