Self-Assembly of Peptide-Conjugated Forklike Mesogens at Aqueous/Liquid Crystalline Interfaces: Molecular Design for Ordering Transition Induced by Specific Binding of Biomolecules

Self-assembly of functional liquid crystals providesa powerfulapproach to the development of stimuli-responsive materials and interfaces.Here, we have designed and synthesized bioconjugated amphiphilic dendriticmesogens containing arginine-glycine-aspartic acid (RGD)peptide sequence to develop new biofunctional aqueous/liquid crystallineinterfaces. We have found that the RGD peptide-conjugated forklikemesogens induce the homeotropic alignment of liquid crystals at theaqueous interfaces, leading to distinct optical changes caused bythe specific binding of the target proteins. In contrast, no responseto the target protein is observed for the interfaces prepared withthe RGD peptide-conjugated single mesogen. Molecular insights intothe orientation and stimuli-responsiveness of the bioconjugated mesogensat the interfaces are obtained based on measurements of the Langmuirfilms and self-assembled properties of these molecules. These resultsdemonstrate that the number of rodlike cores of the bioconjugatedmesogens affects the monolayer structures formed at the aqueous interfaceas well as the liquid crystalline properties. We propose a new moleculardesign of bioconjugated mesogens to couple biomolecular interactionsat the aqueous interfaces with the ordering transition of the liquidcrystals. These materials have the potential to tailor the responsivenessof liquid crystalline interfaces for biomolecular sensing.

Automated summary

Self-assembled bioconjugated dendritic mesogens with arginine-glycine-aspartic acid (RGD) peptide sequence were synthesized and used to develop new biofunctional aqueous/liquid crystalline interfaces. It was found that RGD peptide-conjugated forklike mesogens induced the homeotropic alignment of liquid crystals at the aqueous interfaces, resulting in distinct optical changes upon specific binding of target proteins. Molecular insights into the orientation and stimuli-responsiveness of these mesogens were obtained based on measurements of Langmuir films and self-assembled properties. A new molecular design of bioconjugated mesogens was proposed to couple biomolecular interactions at the aqueous interfaces with the ordering transition of liquid crystals, with potential applications in biomolecular sensing.