Abstract: Liquid crystal-based devices for detecting a target contaminant in air, including hydrogen, nitrogen dioxide, ozone, ammonia or carbon monoxide, and methods of using such devices to detect the target contaminant are disclosed. Such devices have a substrate surface that includes one or more metals or metal alloys that is in contact with a liquid crystal composition. When the device is contacted with a sample that contains the target contaminant, an observed change in the orientational ordering of the liquid crystal signals the presence of the target contaminant. In the absence of the target contaminant, no change in orientational ordering occurs.

Abstract: Liquid crystal-based devices for detecting chlorine in a sample and methods of using such devices to detect chlorine are disclosed. Such devices have a substrate surface that includes either metal cations or a metal that is in contact with a composition that includes a liquid crystal. When the device is contacted with a sample that contains chlorine, an observed change in the orientational ordering of the liquid crystal signals the presence of the chlorine. In the absence of chlorine, no change in orientational ordering occurs.

Abstract: Liquid crystal-based devices for detecting chlorine in a sample and methods of using such devices to detect chlorine are disclosed. Such devices have a substrate surface that includes either metal cations or a metal that is in contact with a composition that includes a liquid crystal. When the device is contacted with a sample that contains chlorine, an observed change in the orientational ordering of the liquid crystal signals the presence of the chlorine. In the absence of chlorine, no change in orientational ordering occurs.