文摘
With the progressive understanding of liquid crystal materials that rely on the interface interactions, optical properties of liquid crystal are attracting attention as a detector for chemicals and biomolecules. In this work, a recently reported liquid crystal sensing system based on the competitive inclusion effect of β-cyclodextrin (β-CD) was studied. Quantum mechanical calculations were applied to study different β-CD inclusion complexes of methyl blue (MB), 4-cyano-4′-pentyl biphenyl (5CB), sodium dodecyl sulfonate (SDS), dopamine (DA) and their inclusion processes. The work shows that DA cannot be an analyte for the liquid crystal sensor as it could not compete for the cavity of β-CD with SDS. However, MB molecule can push SDS out of the β-CD cavity so as to induce the change in optical appearance when MB forms a 1:2 inclusion complex. The simulated absorption spectrum is in agreement with experiment results, implying that MB molecule may exist in both 1:1 and 1:2 inclusion complexes in the system of liquid crystal sensor.
