(241a) Principles for Biosensing Based on Liquid Crystals

Liquid crystals are fluid yet ordered phases that are well-known to assume orientations near interfaces that reflect the molecular structure and organization of adsorbates. These general characteristics make liquid crystalline phases promising candidates for the design of materials that can amplify the presence of biological molecules and their assemblies into optical outputs for biological sensing. This talk will address several key challenges that we are exploring to realize this potential. A first key challenge relates to the design of amphiphilic molecules that can couple biomolecular interactions to ordering transitions in liquid crystals. This presentation will describe a general approach that revolves around the use of amphiphilic copolymers that integrate monomers with side chains that either encode specific biological interactions or couple the organizations of the polymers to the ordering of liquid crystals. A second key challenge addresses the influence of size and shape of liquid crystalline domains on responses to biomolecular interactions. Specifically, I will describe how the elastic properties of liquid crystals can be manipulated by geometry to create exquisitely sensitive sensors of targeted biological molecules (proteins and lipids). Finally, the challenge of optical transduction will be described. In particular, the use of low-cost, flow focusing and light scattering methods will be shown to permit rapid, quantitative characterization of the internal configurations of micrometer-scale liquid crystalline droplets.