Prompt and portable chemical fingerprinting analysis of complex liquids using diamond-based electronic tongue

Chemical fingerprinting analysis using a diamond-based electronic tongue enables wide-range (>5V) voltammetry scanning with highly sensitive signal detection because of their chemical inertness and a large potential window. To measure the robustness of chemical fingerprints, spectral stability, and similarity were evaluated using complex liquids by cyclic voltammetry. Cyclic voltammograms showed different intensities and peak shapes depending on the sample variety, even among similar types of beverages. The similarity of chemical fingerprints as evaluated by the Euclidean distance was kept as high as >90% among identical liquids and it largely decreased against non-identical solutions. The similarity score dispersion is high enough as fingerprinting information and it could be utilized for data analysis applications including anomaly detection and authenticity determination. The diamond-based electronic tongue designed for single-use concept does not necessitate the recalibration of sensors and it possesses significant potential for prompt and portable fingerprinting analysis which is also attractive as platform devices to obtain rich information for machine learning.