Chiral Liquid Crystal Microdroplets for Sensing Phospholipid Amphiphiles

Area of Science:

• Materials Science
• Biophysics
• Nanotechnology

Background:

• Developing simple, sensitive, fast, and inexpensive readout devices for biological molecules and biomarkers is critical for early diagnosis and treatment.
• The interface between chiral liquid crystals (CLCs) and biomolecules presents an opportunity for novel sensing mechanisms.

Purpose of the Study:

• To investigate the interaction between chiral liquid crystal (CLC) droplets and a specific phospholipid (1,2-diauroyl-sn-glycero3-phosphatidylcholine, DLPC).
• To understand how CLC molecular ordering within droplets is affected by DLPC concentration and chirality.
• To explore the potential of CLC-biomolecule interactions for developing advanced biosensing applications.

Main Methods:

• Preparation of CLC droplets with varying chirality (high and low) using microfluidic devices.
• Utilizing cross-polarized optical microscopy to observe molecular reorientation.
• Employing spectrometry and image analysis to monitor changes in Bragg reflection and correlate them with molecular structure.

Main Results:

• Chiral LC droplets undergo a multistage transition from planar to homeotropic ordering upon interaction with DLPC.
• The molecular reconfiguration process in low-chirality droplets is approximately three times faster than in high-chirality droplets.
• Changes in the Bragg reflection of chiral droplets are directly correlated with the interactions between CLCs and DLPC.

Conclusions:

• The study demonstrates a controllable molecular reorientation in chiral LC droplets induced by phospholipids.
• The observed difference in reconfiguration speed between low and high chirality droplets offers a tunable parameter for biosensor design.
• The correlation between Bragg reflection changes and CLC-DLPC interactions provides a basis for sensitive detection of biomolecules.