Devices and methods for using changes in the orientation of
micrometer sized dispersed
liquid crystal domains to detect or quantify analytes in a
test sample, including amphiphilic analytes, are disclosed. The dispersed
liquid crystal domains are defined by an interface, and one or more nanoparticles or
nanoparticle-containing complexes are adsorbed to the interface. As a result of the adsorption of the nanoparticles or
nanoparticle-containing complexes at the interface, the microdomains are stabilized, and
resist coalescing for extended periods of time, unlike previously known devices using
liquid crystal emulsions for
analyte detection.When the dispersed liquid
crystal microdomains are exposed to the
test sample, any changes in the orientation of the liquid
crystal microdomains (such as from the bipolar to radial) are detected. Such changes in orientation
signal the presence of
analyte in the
test sample, and the proportion of liquid
crystal microdomains exhibiting the change in orientation is correlated with the quantity of
analyte in the test sample. The
nanoparticle used, the
amphiphile used in the nanoparticle-containing complex, or both may be selected to optimize the sensitivity and / or selectivity of the device for a given analyte.