Novel voltammetric electronic tongue approach using polyelectrolyte modifiers to detect charged species

A voltammetric electronic tongue has been devised through modification of electrode surface via a highly robust conducting graphite ink incorporating selected polyelectrolytes. These can be neutral (polystyrene or acrylamide), cationic (polyDADMAC) or anionic (EGMP), providing in this way differentiated electroactivity towards analytes having redox signal but with different net charge. In this manner, a voltammetric electronic tongue of this nature has been setup and used for the resolution of mixtures of acetaminophen, ascorbic acid and uric acid, species with different charge at the studied pHs (2.3, 4.8, 7.5 and 10.3). Final quantification of ternary mixtures of these compounds was achieved using the windowed sliced integral method to reduce the data dimensions followed by an artificial neural network model, achieving correlations r > 0.969 for the external test subset (n=10 samples).