Paper-based electrochemical sensor for on-site exhaled breath analysis - Measurement setup

This high-resolution version of the "On-chip CRISPR/Cas13a cleavage" video visualizes the “one-for-all” sensor chip handling and cleavage process and is the Supplementary video of article "Toward Continuous Monitoring of Breath Biochemistry: A Paper-Based Wearable Sensor for Real-Time Hydrogen Peroxide Measurement in Simulated Breath", published in ACS Sensors (https://doi.org/10.1021/acssensors.9b01403).

Here, we report the first disposable paper-based electrochemical wearable sensor that can monitor exhaled hydrogen peroxide (H₂O₂) in artificial breath calibration-free and continuously, in real time, and can be integrated into a commercial respiratory mask for on-site testing of exhaled breath. To improve precision for sensing H₂O₂, we perform differential electrochemical measurement by amperometry in which screen-printed Prussian Blue-mediated and nonmediated carbon electrodes are used for differential analysis. We were able to measure H₂O₂ in simulated breath in a concentration-dependent manner in real time, confirming its functionality. This proposed system is versatile, and by modifying the chemistry of the sensing electrodes, our method of differential sensing can be extended to continuous monitoring of other analytes in exhaled breath.