Continuous Monitoring of Psychosocial Stress by Non-Invasive Volatilomics

Stress is becoming increasingly commonplace in moderntimes, makingit important to have accurate and effective detection methods. Currently,detection methods such as self-evaluation and clinical questionnairesare subjective and unsuitable for long-term monitoring. There havebeen significant studies into biomarkers such as HRV, cortisol, electrocardiography,and blood biomarkers, but the use of multiple electrodes for electrocardiographyor blood tests is impractical for real-time stress monitoring. Tothis end, there is a need for non-invasive sensors to monitor stressin real time. This study looks at the possibility of using breathand skin VOC fingerprinting as stress biomarkers. The Trier socialstress test (TSST) was used to induce acute stress and HRV, cortisol,and anxiety levels were measured before, during, and after the test.GC-MS and sensor array were used to collect and measure VOCs.A prediction model found eight different stress-related VOCs withan accuracy of up to 78%, and a molecularly capped gold nanoparticle-basedsensor revealed a significant difference in breath VOC fingerprintsbetween the two groups. These stress-related VOCs either changed orreturned to baseline after the stress induction, suggesting differentmetabolic pathways at different times. A correlation analysis revealedan association between VOCs and cortisol levels and a weak correlationwith either HRV or anxiety levels, suggesting that VOCs may includecomplementary information in stress detection. This study shows thepotential of VOCs as stress biomarkers, paving the way into developinga real-time, objective, non-invasive stress detection tool for well-beingand early detection of stress-related diseases.