We report a new class of dynamically reconfigurable complex colloids comprising immiscible liquid crystals (LCs) and fluorocarbon oils. Producing stable spherical droplets requires the utilization of appropriately designed surfactants to reduce the high intrinsic surface tension between the LCs and the fluorocarbon oils that initially lead to non-spherical, "snowman-shaped" Janus droplets. After stabilizing the interfaces via surfactants, the LC droplet morphology can be dynamically switch between LC-in-fluorocarbon-in-water double emulsions (LC/F/W), spherical Janus emulsions, and inverted double emulsions (fluorocarbon-in-LC-in-water, F/LC/W) in response to changes in the surrounding surfactants. These stabilization methods can be extended to smectic LCs to create droplets with more complex internal arrangements and expand the range of LC emulsions that can be prepared. In addition, by using new mesogenic surfactants that control the LC director field at each LC-interface, we prepare LC complex colloids exhibiting different internal configurations. The ability to control the LC anchoring conditions made possible to create topological singularities as powerful templates for the precision assembly of antibodies at the droplets' interface. These dynamic LC complex colloids of controllable morphology and LC orientation are rich soft materials platforms that will find utility in a variety of sensing applications.
Herein we describe a highly responsive optical biosensor based on dynamic complex liquid crystal (LC) emulsions. These emulsions are simple to prepare and consist of immiscible chiral nematic liquid crystals (N*) and fluorocarbon oils. In this work, we exploit the N* selective reflection to build a new sensing paradigm. Our detection strategy is based on changes in the LC/ water interfacial activity of boronic acid polymeric surfactants caused by reversible interactions with IgG antibodies at the LC interface. Such biomolecular recognition events can vary the pitch length of the N* organization due to the presence of binaphthyl units in the polymeric structure, which are known to be powerful chiral dopants. We demonstrate that these interface-triggered reflection changes can be used as an effective optical read-out for the detection of the foodborne pathogen Salmonella.
A new class of light-responsive supramolecular amphiphilic block copolymers (BCs) based on the association through multiple H-bonding between 4-isobutyloxyazobenzene motifs and 2,6diacylaminepyridine units is reported. Block copolymers containing 2,6-diacylaminopyridine side units, as hydrophobic block, and poly(ethylene glycol), as a hydrophilic segment, were functionalized with either a carboxylic acid azodendron, via double H-bonding, or a thymine azobenzene, via triple H-bonding. The structural and thermal characterization of these supramolecular azo-copolymers in bulk and solution is presented. The work emphasizes the selfassembly of these supramolecular polymers in water and the study of their UV-light responsive properties by UV-vis spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM), and synchrotron small-angle X-ray (SAXS). The present noncovalent postpolymerization functionalization strategy has provided stable self-assemblies in water with light responsive properties that can be used to load and trigger the delivery of small fluorescent molecules.
We have successfully developed a new strategy for the preparation proton conductive materials using ionic LC dendrimers combined with a crosslinking reaction based on coumarin photodimerization.
DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:
We assess the assembly of supramolecular complexes by hydrogen bonding between azocompounds and a diacylaminopyridine monomer by temperature-dependent Fourier transform infrared spectroscopy (FT-IR) and density functional theory (DFT) calculations. The electronic delocalisation in the supramolecular rings formed by multiple hydrogen bonds stabilises the complexes, which coexist with dimeric species in temperature-dependent equilibria. We show how the application of readily available molecular modelling and spectroscopic techniques can predict the stability of new supramolecular entities coexisting in equilibria, ultimately assessing the success of molecular recognition.
The spread of the COVID-19 pandemic around the world has revealed that it is urgently
important to develop rapid and inexpensive assays for antibodies in general and
anti-SARS-CoV-2 IgG antibody (anti-SARS-CoV-2 spike glycoprotein S1 antibody) in
particular. Herein we report a method to detect the anti-SARS-CoV-2 spike antibody level
by using Janus emulsions or Janus particles as biosensors. Janus emulsions are composed
of two immiscible hydrocarbon and fluorocarbon oils. The hydrocarbon/water interfaces
are functionalized with a secondary antibody of IgG protein and SARS-CoV-2 spike
receptor binding domain (RBD), to produce two different Janus emulsions. Mixtures of
these Janus droplets enable the detection of the anti-SARS-CoV-2 spike IgG antibody in
an agglutination assay caused by the antibody’s binding to both the secondary
antibody of IgG antibody and SARS-CoV-2 spike protein RBD. Both qualitative optical
images and quantitative fluorescence spectra are able to detect the level of
anti-SARS-CoV-2 spike antibody at concentrations as low as 0.2 μg/mL in 2 h. The
detection results of clinical human serum samples using this agglutination assay confirm
that this method is applicable to clinical samples with good sensitivity and
specificity. The reported method is generalizable and can be used to detect other
analytes by attaching different biomolecular recognition elements to the surface of the
Janus droplets.
Efficient syntheses that incorporate thiophene units into different extended conjugation systems are of interest as a result of the prevalence of sulfur-rich aromatics in organic electronics.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.