Detection of Ascorbic Acid in Tears with an Extended-Gate Field-Effect Transistor-Based Electronic Tongue Made of Electropolymerized Porphyrinoids on Laser-Induced Graphene Electrodes

Porphyrinoids are suitable sensitive materials for potentiometric electronic tongues. In this paper, we take advantage of these properties to develop an electronic tongue using an extended-gate field-effect transistor as a signal transducer. The sensitive films were made of different porphyrins and corroles electropolymerized in situ onto laser-induced graphene electrodes. The electronic tongue was duly characterized with respect to ascorbic acid, a common natural antioxidant. The sensors were shown to be sensitive and selective with respect to common interferents, such as dopamine and uric acid. Finally, the sensors were tested to detect ascorbic acid in artificial tears.