Highly sensitive and selective colorimetric sensing of CO 2 for biomedical applications

The concentration of carbon dioxide (CO ) in unhealthy people differs greatly from healthy people. High-precision CO detection with a quick response time is essential for many biomedical applications. A major focus of this research is on the detection of CO , one of the most important health biomarkers. We investigated a low-cost, flexible, and reliable strategy by using dyes for colorimetric CO sensing in this study. The impacts of temperature, pH, reaction time, reusability, concentration, and dye selectivity were studied thoroughly. This study described real-time CO analysis. Using this multi-dye method, we got an average detection limit of 1.98 ppm for CO , in the range of 50-120 ppm. A portable colorimetric instrument with a smartphone-assisted unit was constructed to determine the relative red/green/blue values for real-time and practical applications within 15 s of interaction and the readings are very similar to those of an optical fiber probe. Environmental and biological chemistry applications are likely to benefit greatly from this unique approach.