Voltammetric E-tongues

A. Gutes, F. Cespedes, S. Alegret, and M. del Valle. Sequential injection system with higher dimensional electrochemical sensor signals. Part 1. Voltammetric e-tongue for the determination of oxidizable compoimds. Talanta 66 1187-1196,2005. 

New techniques are being applied to develop miniaturized sensor arrays such as screen printing for thick film and electron beam evaporation, thermal vacuum deposition, and pulsed laser deposition for thin-film technique. Microfabrication techniques were used to prepare a sensor array for use in a voltammetric e-tongue by depositing gold (Au), platinum (Pt), iridium (Ir), and rhodium (Rh) on a silicon wafer. 

Ceto, X., Apetrei, C., del Valle, M. Rodriguez-Mendez, M. L. (2014). Evaluation of red wines antioxidant capacity by means of a voltammetric e-tongue with an optimized sensor array. Electrochim. Acta, 120, 180-186. 

The CV and chronoamperometric data recorded showed that the wearable sensor could be used as a new transcutaneous oxygen sensor, enabling evaluating the oxygen level in the conjunctiva of a rabbit without any thermoregulation. An automatic sequential injection voltammetric E-tongue was described by Gutes et al. (2(X)7) to determine oxidizable compounds of clinical and pharmaceutical interest, such as ascorbic acid, uric acid, and paracetamol. 

Twomey et al. (2011) showed that a four electrodes (Au, Pt, Ir, and Rh) voltammetric E-tongue probe could be used to evaluate different biological fluids, namely gut fluids. CV was used to obtain chemical information (in vivo) from gut model fluids and the different signal profile shapes highlighted the discrimination capability and the potential of such device as a tool for gastrointestinal fluid investigation. 

Apetrei, I.M., Apetrei, C., 2013. Voltammetric e-tongue for the quantification of total polyphenol content in olive oils. Food Res. Int. 54, 2075-2082. 

Apetrei, C., Apetrei, 1. M., Nevares, L, Del Alamo, M., Parra, V., Rodriguez-Mendez, M. L., and De Saja, J. A. (2007). Using an e-tongue based on voltammetric electrodes to discriminate among red wines aged in oak barrels or aged using alternative methods. Electrochhn. Acta 52(7), 2588-2594. 

Gutes, A., Ibanez, A. B., del Valle, M., and Cespedes, F. (2006). Automated SIA e-tongue employing a voltammetric biosensor array for the simultaneous determination of glucose and ascorbic acid. Electroanalysis 18(1), 82-88. 

Ivarsson, P., Kikkawa, Y., Winquist, F., Krantz-Ruelcker, C., Hoejer, N.-E., Hayashi, K., Toko, K., and Lundstroem, I. (2001). A comparison of a voltammetric electronic tongue and a lipid membrane taste sensor with respect to separation of detergent. Chem. Sens. 17 (Suppl. B), 101-103. 

P. Ivarsson, S. Holmin, N.-E. Hojer, C. Krantz-Rulcker and F. Winquist, Discrimination of tea by means of a voltammetric electronic tongue and different applied waveforms, Sens. Actuators B, 76 (2001) 449-454. 

Ivarsson R, Johansson M., Hojer N.-E., Krantz-Rulcker C., Winquist R, and Lundstrom L, Supervision of rinses in a washing machine by a voltammetric electronic tongue, Sens. Actuators B, 108(1-2), 851, 2005. 

E-tongues can be found in different versions according to the detectors employed electrochemical (potentiometric, voltammetric, amperometric, impedimetric, or conduc-timetric), optical, mass and enzymatic sensors (biosensors). One example is a taste sensor made by potentiometric electrodes coated with a lipid layer, another one is a taste analyzer made by ChemFET. 

Some works have been reported concerning the use of voltammetric sensor devices for pharmaceutical applications. SideTnikov et al. (2015) showed the capability of a voltanunetric E-tongue (containing carbon electrodes modified by polyarylene phtha-lides) to identily antiarrhythmic medicines from several producers. Overall, the results highlighted that the voltammograms of medicines could serve as virtual prints and be used for their identification and for quality control. 

Bagnasco, L., Cosulich, M.E., Speranza, G., Medini, L., Oliver , P., Lanteri, S., 2014. Application of a voltammetric electronic tongue and near infrared spectroscopy for a rapid umami taste assessment. Food Chem. 157, 421-428. 

K. Twomey, E. Alvarez de Eulate, J. Alderman, D.W.M. Anigan, Fabrication and chtnacteri-zation of a miniaturized planar voltammetric sensor array for use in an electronic tongue. Sens. Actuators B Chem. 140(2), 532-541 (2009)... 

---