Specific, reversible, and wide-dynamic range sensor for real time detection of carbon dioxide

A pocket-sized multifunctional CO2 detector for use in predicting pulmonary disease comprising:

• a non-invasive CO2 detection chamber including a gas inlet and a gas outlet;
• a CO2 sensor housed in the CO2 detection chamber in direct fluid communication with the gas inlet, where the sensor includes a reversible and selective pH-sensitive nanocomposite sensor element including m-cresol purple, thymol blue, or bromothymol blue for CO2 detection, and a porous hydrophobic surface with microstructures, wherein the porous hydrophobic surface includes a plurality of microstructures made of fluorinated polymers or fluorinated surfaces that have large surface-to-volume ratio providing dense reactive sites to promote the formation of nano-sized reaction clusters;
• a flowmeter;
• a thermistor;
• a humidity sensor;
• at least one light source coupled to receive signals from the CO2 sensor and respond to color changes in the sensor by transducing the color change into a light intensity change;
• at least one photodiode coupled to receive signals from the at least one light source and which responds to light intensity changes by transducing the light intensity changes into electronic signals representing varying degrees of light intensity;
• a power source coupled to power the CO2 detector elements;
• and
• a microcontroller electronically coupled to the flowmeter, thermistor, the humidity sensor and the photodiode.