Trans 4 hydroxy l proline trans hyp

Sunset Yellow (SSY,
Sigma-Aldrich) was used as received. At room temperature, it is a
red powder and shows a nematic phase if dissolved in water above 28%
in weight. Chirality is induced doping the SSY with a proper amount
of trans-4-Hydroxy-l-proline (Trans-Hyp)
from Sigma-Aldrich. Paraffin oil and Span80 were purchased from Sigma-Aldrich.
A mixture of paraffin oil and Span80 was used as an oil matrix in
the microfluidic device. Nonchiral SSY liquid crystal mixtures were
prepared using deionized water (18.2 MΩ cm) to make a solution
of known concentration and phase (30% wt for SSY). For chiral mixtures,
we added 16% wt and 26% wt Trans-Hyp (dissolved in water) to 30% wt
SSY.

DSCG (Figure 1a) was purchased from Sigma-Aldrich (Steinheim, Germany) and used without further purification. When dissolved in water it stacks in cylinder formations, the length of which depends on temperature and concentration; the cylinders then give rise to a nematic phase. At room temperature, the nematic phase exists between 12 and 16 wt% (Figure 1b) [20 (link)].
Trans-4-Hydroxy-L-proline (Trans-Hyp) was purchased from Sigma-Aldrich (Figure 2a), and a solution of 26% of Trans-Hyp in ultrapure water was used to prepare chiral DSCG.
L-alanine, a non-polar left-hand amino acid, was purchased from Sigma-Aldrich (Figure 2b). For the chiral mixture, DSCG was dissolved in 10% w/w L-alanine water solution.
Oxazine 725 (Exciton, Lockbourne, OH, USA) is a fluorescent dye, with a positive charge. In water, it has an absorption peak at 650 nm and an emission peak at 725 nm. Its molecular structure is shown in Figure 2c. It was added to chromonic solution in a percentage less than 1‰.