Simultaneous assessment of volatile organic compound-based urinary and exhaled breath tests for diabetes diagnosis by using E-nose and VE-tongue systems

Diabetes is a lifelong condition that may cause death and seriously affects the quality of life of a rapidly growing number of individuals. Thanks to their advantages, such as sensitivity, economic cost and ease of handling, the use of electrochemical devices could be very useful for the early, non-invasive and real-time diagnosis of diseases. The aim of this study is to compare breath and urine profiles of diabetes patients (DM) and healthy controls (HC) by using an electronic nose (E-nose) and a voltammetric electronic tongue (VE-tongue) combined with appropriate pattern recognition methods. The E-nose is based on five tin oxide (SnO2) sensors, while the VE-tongue consists of five metal electrodes. To this end, data gathered from both devices are treated by chemometric tools including principal component analysis (PCA), and discriminant function analysis (DFA) for easy visualization, interpretation and discrimination. As a result, PCA showed good discrimination between data-points of breath samples of DM patients and HC, with cumulative PCA scores of 98.17%. Furthermore, the DFA method revealed a clear separation among urine samples corresponding to DM patients and HC. Based on these results, the two proposed devices could be considered as a non-invasive tools for screening of diabetes diagnosis.