Disposable chemical sensor arrays and breath monitoring system

A device for detecting one or more gases of ammonia (NH3), trimethylamine (TMA), and hydrogen sulfide (H2S), comprising:

• a substrate,
• an interdigitated electrode layer mechanically coupled with the substrate, the interdigitated electrode layer including multiple pairs of electrodes;
• a gas sensor array including multiple gas sensing films electronically coupled with the interdigitated electrode layer, a respective gas sensing film of the multiple gas sensing films configured to chemically interact with a target gas, wherein:
• one or more pairs of electrodes of the interdigitated electrode layer are mechanically coupled to the respective gas sensing film of the gas sensor array,
• the one or more pairs of electrodes are configured to measure resistance changes across the respective gas sensing film upon chemical interaction with the target gas, and
• the multiple gas sensing films include one or more of:
• polyaniline (PANI)-based conducting polymer doped with camphor sulfonic acid (CSA) for chemically interacting with NH3 and/or TMA;
• PANI-based conducting polymer doped with 4-dodecylbenzenesulfonic acid (DBSA) for chemically interacting with TMA and/or NH3;
• and
• metal salt-doped PANI with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) composite for chemically interacting with H2S.