Polyaniline/Prussian blue nanolayer enhanced electrochemical sensing of H2O2 in EBC using an integrated condensation facemask

The low concentration of respiratory H2O2 requires high detection sensitivity and stability. In this work, a Polyaniline/Prussian Blue Nanolayer (nano-PANI/PB) coated electrode using a 30 nm porous alumina template was fabricated to enhance the roughness of the electrode surface to improve the sensitivity of H2O2 detection. The limit of detection of 2.52 μM was realized within a detection range of 0–1 mM. In addition, a condensing device that uses microchannel with a secondary flow structure was designed with computational fluid dynamics to downsize the exhaled breath condensing device and improve the condensing efficiency. Increasing the contact area between exhaled breath and condensing materials in the microchannel can obviously increase the amount of condensate. The performance of the condensing device was visualized through the condensing of sodium fluorescein solution. A multichannel condensing device was integrated with screen printing electrode, three-electrode detection circuit and display module into a N95 mask to realize portable Exhaled breath condensate (EBC) detection and showed a favorable feasibility. The application of this portable exhaled breath measurement device could be expanded through modifying the specific biomarker probes on electrode, and may provide some inspirations for the development of wearable and portable non-invasive healthy monitoring devices.