SUMMARY: Scientists are trying to create electronic tongues (eT) and noses (eN) that act like human tongues and noses. These artificial sensors are different from traditional sensors in that they don’t recognize individual molecules, but heterogeneous liquids and gases. In this article, scientists were able to use a combination of surface plasmon resonance imaging (imaging using metal atoms and the changes in electron excitation states) and cross-reactive sensor array (using pattern recognition to sense mixtures) and artificial intelligence to train their eT. They started with pure samples, then moved on to common liquids (milk, wine, etc). Researchers found that their eT was able to recognize different liquids (results are shown in both 3D and 2D graphs) and was even able to recognize milk going bad. This type of technology could be very useful in figuring out water quality or air quality.
LESSON COMMENTS: This article is a great example of the application of all disciplines of science. Biology teachers can mix this with engineering projects, asking students to model or draw up design plans for their own electronic tongue or nose. Chemistry teachers can go in-depth into how surface plasmon resonance imaging works. More advanced biology or biochemistry classes can look at the difference between the Western blot versus the cross-reactive sensor array. Computer programming classes can look at the methodology to see how machine learning works and create their own projects with various open source codes. Environmental science classes can use this article to talk about the new technologies being developed that can help monitor pollution levels in water and air. Feel free to break down the article into its various parts as well, it can easily be used in chunks.
Garçon, L. A., Genua, M., Hou, Y., Buhot, A., Calemczuk, R., Livache, T., … Hou, Y. (2017). A Versatile Electronic Tongue Based on Surface Plasmon Resonance Imaging and Cross-Reactive Sensor Arrays-A Mini-Review. Sensors (Basel, Switzerland), 17(5), 1046. doi:10.3390/s17051046