Wisconsin Alumni Research Foundation

Analytical Instrumentation
Analytical Instrumentation
Devices and Methods for Analyte Detection Using Distorted Liquid Crystals
WARF: P05453US

Inventors: Nicholas Abbott, Brian Clare

The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing an alternative means of detecting liquid crystal signals in response to biomolecular interactions.
Previous methods of using liquid crystals to detect post-translationally modified peptides worked by detecting a change in the orientation of liquid crystals in the presence or absence of a target analyte.
The Invention
UW-Madison researchers have developed an alternative means of detecting liquid crystal signals in response to biomolecular interactions. This technique involves determining the anchoring strength of a constrained liquid crystal as a function of the molecules bound to the substrate surface. In the absence of any external force, liquid crystals align along the surfaces of a sample with their optical axis along one direction, defined as the “easy axis.” Anchoring strength can be defined as the amount of force required to cause the liquid crystal to not lie along the easy axis. When a liquid crystal is constrained between two surfaces that have their easy axes in two different directions, the liquid crystal is distorted and strained. In that case, the orientation of the liquid crystal is a compromise between two opposing forces: the anchoring strength and the elastic torque resulting from the strain.

To evaluate the anchoring strength of liquid crystals, the researchers developed a slightly modified version of the optical cells typically used to detect biomolecular interaction using liquid crystals. Previous optical cells included two glass substrates separated by thin spacers on each end. One of the surfaces is a reference surface that the liquid crystal is strongly anchored to. The analyte is placed in or on the other substrate surface. In the modified version, a “wedge” optical cell is created by including a spacer on only one end. The easy axis of the substrate surface and the easy axis of the reference surface are rotated from one another by a known angle. If the analyte is present, the orientation of the liquid crystal deviates from the easy axis of the substrate surface in an analyte-dependent manner. The wedge configuration allows the angle of deviation to be measured, enabling the detection and quantification of the analyte.
  • Detecting post-translationally modified peptides
Key Benefits
  • Provides a potentially more sensitive means of monitoring a captured analyte or a change, such a post-translational modification, of an analyte
  • Enables the quantification of low levels of bound analytes
  • No more complicated to use than previous liquid crystal technologies
  • Uses the same kind of equipment as previous methods, although the consumable cell is constructed differently and a different ratio of signals is evaluated to determine the disruption of the liquid crystals in response to the analyte
  • Successfully used to detect antibody bound to a phosphorylated, but not non-phosphorylated, peptide at a low areal density of 0.1 to 1 percent
Additional Information
For current licensing status, please contact Jennifer Gottwald at [javascript protected email address] or 608-960-9854