Microfluidic Electronic Tongue Made with Nanostructured Films of Proteins from Renewable Sources to Detect H5N1 Antibodies from Avian Influenza Virus

High Resolution Image Download MS PowerPoint Slide Avian influenza viruses, particularly the H5N1 subtype, represent a major global threat due to their high transmissibility and mortality rates. Rapid, low-cost, and reliable detection is essential for controlling viral spread in both avian and human populations. This work presents a microfluidic electronic tongue composed of interdigitated electrodes functionalized with one-layer, nanostructured films from renewable sources zein, jacalin, concanavalin A, and sericin-modified gold nanoparticles (AuNP-SER) for the detection of anti-H5N1 antibodies. Electrical impedance spectroscopy was employed to monitor the interaction between antibodies and molecular architectures, supported by contact angle and polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS) analyses to elucidate the detection mechanism. The sensors exhibited high sensitivity and selectivity, with limits of detection ranging from 0.42 to 0.56 ng/mL and no false positives when tested against common avian disease antibodies. Information visualization techniques demonstrated strong discrimination among analytes, with silhouette coefficients up to 0.81 for the electronic tongue. Using the multidimensional calibration space (MCS) approach with decision-tree models, the system achieved 78% accuracy in multiclass classification of 10 antibody concentrations and 98.6% accuracy in distinguishing positive from negative samples. The MCS revealed that the 2154 Hz frequency from the AuNP-SER unit was influential in both scenarios. These results confirm the potential of the electronic tongue proposed as a robust, interpretable, and low-cost diagnostic tool for H5N1-related diseases in veterinary and clinical contexts.