Using liquid crystals to detect DNA hybridization on polymeric surfaces with continuous wavy features

Area of Science:

• Materials Science
• Biophysics
• Nanotechnology

Background:

• Thermotropic liquid crystals (LCs) exhibit orientational behavior sensitive to surface interactions.
• Nanostructured surfaces offer tailored environments for molecular assembly and sensing.
• Deoxyribonucleic acid (DNA) immobilization is a key strategy for creating biospecific surfaces.

Purpose of the Study:

• To investigate the orientational response of liquid crystals (LCs) on DNA-modified nanostructured surfaces.
• To explore the potential of LC-DNA interactions for detecting DNA hybridization events.
• To understand how surface nanostructure and DNA functionalization influence LC behavior.

Main Methods:

• Fabrication of gold-coated, sinusoidally patterned polymer substrates.
• Immobilization of thiol-modified DNA onto the gold surface.
• Hybridization of complementary DNA strands (cDNA).
• Observation of nematic 4-cyano-4'-pentylbiphenyl (5CB) orientation using microscopy.

Main Results:

• Surface-immobilized DNA initially directed 5CB orientation parallel to the surface.
• DNA hybridization with cDNA disrupted the surface nanostructure.
• The disruption led to a random orientation of 5CB, indicating a detectable change.
• LC orientation was sensitive to the presence and hybridization state of surface-bound DNA.

Conclusions:

• Liquid crystals can serve as sensitive indicators for DNA hybridization on nanostructured surfaces.
• The orientational changes in LCs correlate with alterations in the DNA-surface complex.
• This study demonstrates a novel approach for label-free DNA detection using LC-DNA-nanostructure interactions.