Electronic tongue based on modified carbon nanotube electrochemical sensor array

In this work, carbon nanotube based electrochemical sensor array was developed as electronic tongue for beer discrimination without sample pretreatment using chronoamperometry. To form the sensor array, carbon nanotubes were modified by oxygen plasma and electrochemical oxidation using NaOH and KClO₃ to yield electrochemical sensors with distinct characteristics. The current sensitivities from differently functionalized CNTs were analyzed by principal component analysis. Four different brands of beer, including Chang Classic, Heineken, Leo and Cheers, have been successfully distinguished by the developed electronic tongue system with high sensitivity.