Electronic tongues potentiometric based-sensor arrays

An automated electronic tongue consisting of an array of potentiometric sensors and an artificial neural network (ANN) was developed to resolve mixtures of anionic surfactants. The sensor array was formed by five different flow-through sensors for anionic surfactants, based on polyvinyl chloride membranes having cross-sensitivity features. 

FIGURE 2.S Differentiation of beverages of very different nature by means of an electronic tongue based on potentiometric sensor arrays (reproduced from Vlasov et al., 2000, with permission). 

In a further study, Dias et al. (2009) studied the deployment of a potentiometric electronic tongue based on an array of 36 sensors, for the recognition of the basic taste sensations and for the detection of fraudulent additions of bovine milk to ovine milk. The signals were processed by means of PCA and LDA (see Fig. 2.26), and the classification rules were evaluated by means of cross-validation. The results presented are excellent for fitting but not very satisfactory for prediction. 

Legin, A., Rudinitskaya, A., Vlasov, Y., Di Natale, C., Davide, F., and D Amico, A. (1996). Tasting of beverages using an electronic tongue based on potentiometric sensor array. In "Technical Digest of Eurosensors X, Leuven", pp. 427-430. Elsevier, Amsterdam. 

For electronic tongues using an array of potentiometric sensors, the calibration model based on an ANN corresponds to across neuron pattern theory applied to the biological system. 

Electronic tongue systems for remote environmental monitoring applications have been presented in several applications. A new approach in the chemical sensor field consists in the use of an array of nonspecific sensors coupled with a multivariate calibration tool which may form a node of a sensor network. The proposed arrays were made up of potentiometric sensors based on polymeric membranes, and the subsequent cross-response processing was based on a multilayer artificial neural network model as proposed by Mimendia et al. who described environmental monitoring of ammonium as a pollutant plus alkaline ions at different measuring sites in the states of Mexico and Hidalgo (Mexico), and monitoring of heavy metals (Cu ", Pb ", Zn ", and Cd " ) in open-air waste streams and rivers. 

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