▎ 摘　　要

NOVELTY - The gas sensing element has a conductive unit that is set on the substrate, where two electrodes are used for external connection. A sensing layer having polyethylene imine and polyethylene glycol is used for absorbing carbon dioxide gas, set on the conductive unit, and is electrically connected with the electrode. The sensing layer has the polypyrrole and polyaniline. An insulating layer is set on the electrode. The conductive unit has a conductive layer composed of conductive material, where the conductive layer can be selected from conductive macromolecule, graphene, reducing oxidation graphene nanometer carbon tube. The electrode is selected from a carbon electrode. USE - Gas sensing element for use in a detecting system (claimed) for detecting the concentration of carbon dioxide in the breath of a patient suffering from chronic obstructive pulmonary disease (COPD). ADVANTAGE - The gas sensing element can be detachably electrically connected on the electric connection seat and can automatically detect the carbon dioxide concentration in the gas to be tested, and avoid producing the patient pain in the detection process. The sensing layer is selected from the combination of polyethylene imine and polyethylene glycol, so as to effectively improve the reaction rate of the polyethylene imine absorbing carbon dioxide that enhances the sensing sensitivity for carbon dioxide. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a carbon dioxide concentration detecting system. DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of the gas sensing element. Sensing layer (3) Insulating layer (4) Strip-shaped electrode (21) Conductive layer (22) Gas sensing element (100)