1. Instituto de Física de São Carlos, USP, CP 369, 13560-970, São Carlos/SP, Brazil;2. Depto de Física, Química e Biologia, FCT-UNESP, CP 467, 19060-900, Presidente Prudente/SP, Brazil;3. EMBRAPA Instrumentação Agropecuária, CP 741, 13560-970, São Carlos/SP, Brazil;4. Laboratório de Microeletrônica, Departamento de Engenharia de Sistemas Eletrônicos, EPUSP, 05508-900, São Paulo/SP, Brazil
Abstract:
Chitosan is alternated with sulfonated polystyrene (PSS) to build layer‐by‐layer (LBL) films that are used as sensing units in an electronic tongue. Using impedance spectroscopy as the principle method of detection, an array using chitosan/PSS LBL film and a bare gold electrode as the sensing units was capable of distinguishing the basic tastes – salty, sweet, bitter, and sour – to a concentration below the human threshold. The suitability of chitosan as a sensing material was confirmed by using this sensor to distinguish red wines according to their vintage, vineyard, and brands.
PCA Plot for red wine samples obtained from impedance measurements at 1 kHz for the sensor array comprising a 3‐bilayer chitosan/PSS film and a bare gold electrode.
