Abstract: Methods for monitoring catalytic chemical reactions are provided. Such a method may comprise (a) exposing a solid surface to conditions to induce a chemical reaction of reactants at an interface formed between the solid surface and a liquid crystal, wherein the solid surface catalyzes the chemical reaction and the liquid crystal is characterized by an anchoring orientation that changes during the chemical reaction; and (b) measuring the anchoring orientation of the liquid crystal at one or more time points and at one or more locations on the solid surface during step (a). Systems for carrying out the methods are also provided.

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: In accordance with some embodiments, methods, systems, and media for detecting the presence of are provided. In some embodiments, a method of detecting an analyte is provided, the method comprising: capturing an image of liquid crystals; determining one or more features based on the brightness of the pixels in the image; providing the one or more features to a trained support vector machine, wherein the support vector machine was trained using images captured of other liquid crystals when exposed to a first analyte and the other liquid crystals exposed to a second analyte; and receiving an indication from the support vector machine indicating whether the liquid crystals have been exposed to the first analyte.

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: In accordance with some embodiments, methods, systems, and media for detecting the presence of are provided. In some embodiments, a method of detecting an analyte is provided, the method comprising: capturing an image of liquid crystals; determining one or more features based on the brightness of the pixels in the image; providing the one or more features to a trained support vector machine, wherein the support vector machine was trained using images captured of other liquid crystals when exposed to a first analyte and the other liquid crystals exposed to a second analyte; and receiving an indication from the support vector machine indicating whether the liquid crystals have been exposed to the first analyte.