We describe director distortions in the nematic liquid crystal (LC) caused by a spherical particle with tangential surface orientation of the director and show that light transmittance through the distorted region is a steep function of the particle's size. The effect allows us to propose a real-time microbial sensor based on a nontoxic lyotropic chromonic LC (LCLC) that detects and amplifies the presence of immune complexes. A cassette is filled with LCLC, antibody, and antigen-bearing particles. Small and isolated particles cause no macroscopic distortions of the LCLC. Upon antibody-antigen binding, the growing immune complexes distort the director and cause detectable optical transmittance between crossed polarizers.
Physical Review E
Copyright 2005 American Physical Society. Available on publisher's site at http://dx.doi.org/10.1103/PhysRevE.71.020702
Shiyanovskii, Sergij V.; Schneider, T.; Smalyukh, Ivan I.; Ishikawa, T.; Niehaus, G. D.; Doane, K. J.; Woolverton, Christopher J.; Lavrentovich, Oleg (2005). Real-time microbe detection based on director distortions around growing immune complexes in lyotropic chromonic liquid crystals. Physical Review E 71(2) 020702. doi: 10.1103/PhysRevE.71.020702. Retrieved from https://oaks.kent.edu/cpippubs/201