Wine analysis with a flow injection electronic tongue based on porphyrinoids functionalized EGFET sensors

Arrays of cross-selective sensors, or electronic tongues, exploit the olfaction-inspired principle of combinatorial selectivity to classify samples based on their overall chemical profiles. This approach is particularly valuable in applications such as medical diagnostics and food quality control, where rapid and reliable analysis is essential. Here, we present a high-throughput electronic tongue that integrates advanced fabrication techniques—including Laser-Induced Graphene (LIG), conductive ink dispensing, and 3D printing—to construct a flow injection system comprising an array of 16 LIG electrodes each connected to the gate terminal of a Field-Effect Transistor. Fifteen electrodes were functionalized with solid-state porphyrinoid layers. The flow injection design allows minimal sample volumes to be injected into a continuous carrier stream, and under these brief exposure conditions, the sensors demonstrate reproducible and reversible responses, enabling rapid and reliable analysis of liquid samples. The electronic tongue was applied to a set of red wines sourced from a single region but produced from different grape varieties. Chemometrics analysis of the sensor signals enabled both classification of wines by variety and quantification of standard wine quality indicators. Optimal sensor subsets were identified for each task, and the predicted indicators preserved the information content of values obtained via conventional laboratory measurements.