Starch-iodine films respond to water vapor Original Research Article

Starch-iodine indicator films were found to have useful spectroscopic properties for the detection of water vapor. The large colorimetric response of these easily prepared films was easily detected by the absorption of 632.8 nm HeNe laser light, using a planar integrated optical waveguide (IOW) platform. The detection limit of a prototype sensor was found to be below 5% relative humidity (RH), with response times of the order of seconds.