Real-time microbe detection based on director distortions around growing immune complexes in lyotropic chromonic liquid crystals

Phys Rev E Stat Nonlin Soft Matter Phys. 2005 Feb;71(2 Pt 1):020702. doi: 10.1103/PhysRevE.71.020702. Epub 2005 Feb 18.

Abstract

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.

Publication types

  • Evaluation Study

MeSH terms

  • Antigen-Antibody Complex / analysis*
  • Bacteria / cytology
  • Bacteria / immunology
  • Bacteria / isolation & purification*
  • Biosensing Techniques / instrumentation
  • Biosensing Techniques / methods*
  • Colony Count, Microbial / instrumentation
  • Colony Count, Microbial / methods*
  • Computer Systems
  • Immunoassay / methods*
  • Microscopy, Fluorescence / instrumentation
  • Microscopy, Fluorescence / methods*
  • Microscopy, Polarization / instrumentation
  • Microscopy, Polarization / methods*
  • Reproducibility of Results
  • Sensitivity and Specificity

Substances

  • Antigen-Antibody Complex