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

Abstract

An electronic tongue is a powerful analytical instrument based on an array of non-selective chemical sensors with a partial specificity for data gathering and advanced pattern recognition methods for data analysis. Connecting electronic tongues with electrochemical techniques for data collection has led to various applications, mostly within sensing for food quality and environmental monitoring, but also in biomedical research for the analyses of different bioanalytes in human physiological fluids. In this paper, an electronic tongue consisting of six electrodes (viz., gold, platinum, palladium, titanium, iridium, and glassy carbon) was designed and tested in authentic (undiluted, unpretreated) human saliva samples from eight volunteers, collected before and during the COVID-19 pandemic. Investigations of 11 samples using differential pulse voltammetry and a principal component analysis allowed us to distinguish between SARS-CoV-2-free and infected authentic human saliva. This work, as a proof-of-principle demonstration, provides a new perspective for the use of electronic tongues in the field of enzyme-free electrochemical biosensing, highlighting their potential for future applications in non-invasive biomedical analyses.

Controlled Insertion of Silver Nanoparticles in LbL Nanostructures: Fine-Tuning the Sensing Units of an Impedimetric E-Tongue

“…and beers [32,33], among others [34][35][36][37][38]. These devices are particularly interesting in scenarios where human assessment is impractical, such as continuous monitoring of industrial processes and analysis of hazardous or unpleasant samples, including drugs [39,40], viruses [41], bacteria [29], toxins [42], and pollutants [43][44][45][46][47].…”

Heterogeneous-Nucleation Biosensor for Long-Term Collection and Mask-Based Self-Detection of SARS-CoV-2

“…Infectious diseases cause serious health and social problems [ 1 ], as is evident from the pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). To date, various state-of-the-art technologies have been established for the precise detection of SARS-CoV-2 [ 2 , 3 ], including the golden standard quantitative reverse transcription-polymerase chain reaction (RT-PCR) [ 4 ] for viruses, serological tests for determining a previous infection, computed tomography or nuclear magnetic resonance methods for diagnosis at hospitals [ 5 ], and antigen-based biosensing for spike proteins or viruses [ 6 ]. Despite their multiple advantages, these technologies are still far from being desirable.…”