Air-permeable redox mediated transcutaneous CO₂ sensor

Standard clinical care of neonates and the ventilation status of human patients affected with coronavirus disease involves continuous CO₂ monitoring. However, existing noninvasive methods are inadequate owing to the rigidity of hard-wired devices, insubstantial gas permeability and high operating temperature. Here, we report a cost-effective transcutaneous CO₂ sensing device comprising elastomeric sponges impregnated with oxidized single-walled carbon nanotubes (oxSWCNTs)-based composites. The proposed device features a highly selective CO₂ sensing response (detection limit 155 ± 15 ppb), excellent permeability and reliability under a large deformation. A follow-up prospective study not only offers measurement equivalency to existing clinical standards of CO₂ monitoring but also provides important additional features. This new modality allowed for skin-to-skin care in neonates and room-temperature CO₂ monitoring as compared with clinical standard monitoring system operating at high temperature to substantially enhance the quality for futuristic applications.