Construction, Working, and Applications of E-Tongue: A Versatile Tool for All Tastes?

Abstract

An Electronic Tongue or E-tongue can be defined as a bio-mimicking sensor generally meant to mimic the ability to taste sweet, sour, bitter, and salty compounds and quantify each of these compounds. In an E-tongue, there are counter/sensing electrodes and a reference electrode. The current generated between the electrodes or the change in the resistance of the electrodes is used as an input for a mathematical model and with the help of computer simulations the taste or the nature of the compound is analyzed. This type analysis is usually seen in systems using electrodes modified with advanced nanocomposites such as graphene, PEDOT: PSS, Molybdenum Disulphide, etc. Here the tendency of the sample to resist the flow of electrons from the working electrode to the reference electrode is measured with input signals constantly varying in frequency and amplitude. This article discusses the methods and construction of E-tongues as well as their application across various fields. We shall also discuss the experimental details of various types of E-Tongue used in different solutions and their results. E-tongues have an important role in wine tasting today as their ability to breakdown the compound and individually analyze the components of the compounds with excellent accuracy is unparalleled.