| abstract |
A chemical substance-sensing element of the invention has a sensor film on a substrate, the sensor film containing a dye and a compound sensitive to a chemical substance such as water, for example, a hydrophilic compound. The sensor film contains a dye and a chemical substance sensitive compound in a common layer or is composed of a dye film and a film of a chemical substance sensitive compound laminated thereto. The light reflectance of the sensor film changes when the chemical substance sensitive compound bonds with a chemical substance to be detected. The chemical substance can be detected and quantitatively measured by directing light from a light-emitting element toward the sensor film and detecting the reflectance of the sensor film by means of a light-receiving element. |