Wearable Electronic Tongue for Non-Invasive Assessment of Human Sweat

Abstract

Sweat is a promising biofluid in allowing for non-invasive sampling. Here, we investigate the use of a voltammetric electronic tongue, combining different metal electrodes, for the purpose of non-invasive sample assessment, specifically focusing on sweat. A wearable electronic tongue is presented by incorporating metal electrodes on a flexible circuit board and used to non-invasively monitor sweat on the body. The data obtained from the measurements were treated by multivariate data processing. Using principal component analysis to analyze the data collected by the wearable electronic tongue enabled differentiation of sweat samples of different chemical composition, and when combined with 1H-NMR sample differentiation could be attributed to changing analyte concentrations.

Bacteria-Infected Artificial Urine Characterization Based on a Combined Approach Using an Electronic Tongue Complemented with 1H-NMR and Flow Cytometry

“…A possible explanation could be that compounds produced due to the bacterial metabolism may adsorb on the surface and change the electrocatalytic properties of these materials. Similar behavior was recently observed when saliva samples were investigated [35]. To confirm that the differences in the voltammograms were based on altered bacterial metabolism and its redox-active behavior rather than from cell adsorption, the supernatant from all three bacterium types was also electrochemically investigated (Figure S5, Supplementary Materials), where a similar behavior was observed as with bacterial cells in solution [59].…”

“…Principal component analysis (PCA) is commonly used to analyze the response of an e-tongue, which is a method to reduce (big) data sets without losing essential information [28][29][30]32,33]. This approach facilitates the analysis of complex multicomponent fluids like juice, milk, drinks, food and flavors [28,34], and has also recently been used to analyze physiological fluids like virus detection in saliva [35], oral cavity cancer diagnostic in saliva [36], compositional change in sweat [37], urea, creatinine, and ion detection in dialysate fluid [38]. While some efforts have been made to deploy e-tongues for urine analysis, such as different potentiometric electronic tongues for ion analysis as well as the possible use in cancer diagnosis, as far as we know, no studies have been made using electronic tongues for UTI classification [39][40][41][42].…”

Electronic Tongue for Direct Assessment of SARS-CoV-2-Free and Infected Human Saliva—A Feasibility Study

“…So far, e-tongues have been employed for various applications, e.g., the analysis of foodstuff [25,26], beverages including wine [27][28][29][30], and chemicals. E-tongues have also found a use in environmental monitoring [31,32], in the assessment of pharmaceutical formulations [33][34][35], and for the analysis of physiological fluids, like saliva [36,37]), sweat [38], and dialysate fluid [39]. However, regarding COVID-19 detection, only one report was found in the literature.…”

Transducer Technologies for Biosensors and Their Wearable Applications

“…In line with this progress, the continuous tracking of body outputs is now provided by wearable biosensors [ 5 , 21 ]. The breakthrough advantages of wearable technology compared to the conventional bio-analytical methods or POC testing devices are that their continuous monitoring does not require an invasive way to collect samples from the person of interest and can be performed in a user-friendly operation at a low cost [ 22 , 23 , 24 , 25 ]. The academic and industrial interest in wearable technologies greatly attracted the development of new mobile devices advancing biosensors by combining them with new materials and compact electronics.…”