Porous Poly(3,4-ethylenedioxythiophene)-Based Electrodes for Detecting Stress Biomarkers in Artificial Urine and Sweat

When danger is perceived, the human body responds to overcome obstacles and survive a stressful situation; however, sustained levels of stress are associated with health disorders and diminished life quality. Hence, stress biomarkers are monitored to control stress quantitatively. Herein, a porous sensor (4l-COP/p) composed of poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,4-ethylenedioxythiophene-co-N-methylpyrrole) (COP), which is prepared in a four-layered fashion to detect dopamine (DA) and serotonin (5-HT), is presented. Specifically, the detection is conducted in phosphate-buffered saline (PBS), as well as artificial urine and sweat, by applying cyclic voltammetry. The limit of detection values obtained are as low as 5.7 x 10(-6) and 1.4 x 10(-6) m for DA and 5-HT, respectively, when assessed individually in artificial urine. When mixed in PBS, 4l-COP/p detects both biomarkers with a resolution of 0.18 V and a sensitivity of 40 and 30 mu A mm(-1) for DA and 5-HT, respectively. Additionally, by theoretical calculations, the interaction pattern that each stress biomarker establishes with the PEDOT outer layer is elucidated. Whereas DA interacts with the pi-system of PEDOT, 5-HT forms specific hydrogen bonds with the conducting polymer chains. The resolution value obtained depends upon such interactions. Overall, 4l-COP/p electrodes display potential as stress sensing devices for healthcare technologies.

Automated summary

When danger is perceived, the human body responds by releasing stress hormones to help overcome obstacles and ensure survival. However, prolonged exposure to stress can lead to health disorders and reduced quality of life. Therefore, it is important to monitor stress biomarkers to quantitatively control stress levels. In this study, a porous sensor composed of PEDOT and COP is developed to detect the stress biomarkers dopamine (DA) and serotonin (5-HT). The sensor exhibits low detection limits and high sensitivity when tested in artificial urine and phosphate-buffered saline. The interaction patterns between the biomarkers and the sensor material are elucidated through theoretical calculations. Overall, the 4l-COP/p electrodes show promising potential as stress sensing devices in healthcare technologies.