Self-assembled quantum dot microstructure guided by a microemulsion approach for immunoassays

Quantum dot microstructures were fabricated through a convenient microemulsion approach in this study. A polymer solution containing a stabilizer was mixed with a quantum dot aqueous solution, to prepare a reversed microemulsion, through shaking. Then, the microemulsion was cast on a solid substrate followed by evaporating steps, resulting in the formation of an ordered porous film. Interestingly, the quantum dot microstructure can be produced at the same time. The immunoassay experiment could be realized by the fluorescent microstructures. The green fluorescence microstructure specifically bound with antigens marked with red color quantum dots, resulting in the enhancement of red fluorescence domains and the decrease of green fluorescence. With the addition of unlabeled antigens, the green fluorescence microstructure was recovered. This strategy implies that the quantum dot pattern has potential on biochip, biosensor, and imaging analysis.

Ordered nanocrystal microstructures are conveniently prepared via a microemulsion which can further be applied for immunoassays.

Self-organized nanocrystal rings formed by microemulsion for selective recognition of proteins and immunoassays

A simple and cheap method to fabricate a nanocrystal ring pattern was developed by utilization of a microemulsion in this study. The mixture of polystyrene and stabilizer dichloromethane solution that contained nanocrystal aqueous solution, prepared through shaking, was applied to fabricate a reverse microemulsion. After spreading and evaporating the solvent of microemulsion on a glass slide, an ordered honeycomb film was produced, accompanied by the formation of a nanocrystal ring pattern. The nanocrystal pattern could be readily applied for immunoassays and recognition of proteins. The pattern with antibody marked by a green colored nanocrystal specifically bound with antigen labeled by a red colored nanocrystal, leading to the enhancement in red fluorescent ring pattern and decrease in green fluorescent pattern. When the unlabeled antigen was added, the green fluorescent pattern was recovered. In addition, the ring pattern with immunocomplex could selectively recognize antigen and transferrin proteins. This strategy reveals that these patterns have potential applications in biochips, biosensors, imaging analysis and so forth.

Ordered nanocrystal rings were conveniently prepared by a microemulsion, which can further be applied for the recognition of proteins and immunoassays.

Assembly of heteropoly acid into localized porous structures for in situ preparation of silver and polypyrrole nanoparticles

A simple and facile method to fabricate porous films which were locally patterned by heteropoly acid was developed in this study. The mixture of poly(methyl methacrylate) and stabilizer dichloromethane solution which contains heteropoly acid aqueous solution, prepared through shaking, was applied to fabricate a reversed microemulsion. After spreading and evaporating the solvent of microemulsion on a glass slide, an ordered honeycomb film was produced by incorporation of heteropoly acid in the cavities. The locally anchored heteropoly acid could be readily applied for the selective modification of the porous films through the in situ chemical reactions in the cavities with the additive agents. The silver nanoparticles were in situ prepared via the reduction of silver ions by reduced state H₃PW₁₂O₄₀, and the polypyrrole spheres were locally obtained through the oxidative polymerization of pyrrole catalyzed by H₃PMo₁₂O₄₀ in the cavities. Considering that water-soluble molecules and nanoparticles were universally suitable for the present strategy, the reported approach opened up an efficient way for patterning organically incompatible components on porous polymer films via the assembly of microemulsion droplet carriers to fabricate multi-functional hybrid surface structures.

An ordered heteropoly acid patterned porous structure is prepared which can be applied to the preparation of silver and polypyrrole nanoparticles.

Porous membranes based on poly(ether imide)-graft-poly(vinyl acetate) as a scaffold for cell growth

A series of poly(ether imide)-graft-poly(vinyl acetate) copolymers with different molecular weights were synthesized successfully and characterized using Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, proton nuclear magnetic resonance, gel permeation chromatography, differential scanning calorimeter, thermogravimetric analysis, and X-ray photoelectron spectroscopy analyses. These copolymers were used to fabricate honeycomb-structured porous films using the breath figure templating technique. The surface topology and composition of the highly ordered pattern film were further characterized using a scanning electron microscopy. The results indicated that the poly(ether imide)-graft-poly(vinyl acetate) graft molecular weight ratio influenced the breath figure film surface topology. A model was proposed to elucidate the stabilization process of the poly(ether imide)-graft-poly(vinyl acetate)-aggregated architecture on the water droplet–based templates. In addition, cell viability has been investigated via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test, and the cell morphology on the honeycomb-structured poly(ether imide)-graft-poly(vinyl acetate) porous film has been evaluated using a fluorescence microscope. This porous film is shown to be suitable as a matrix for cell growth.

Preparation of Organometal Halide Perovskite Photonic Crystal Films for Potential Optoelectronic Applications

Herein, a facile method for the preparation of organometal halide perovskite (OHP) thin films in photonic crystal morphology is presented. The OHP photonic crystal thin films with controllable porosity and thicknesses between 2 μm and 6 μm were prepared on glass, fluorine-doped tin oxide (FTO), and TiO2 substrates by using a colloidal crystal of polystyrene microspheres as a template to form an inverse opal structure. The composition of OHP could be straightforwardly tuned by varying the halide anions. The obtained OHP inverse opal films possess large ordered domains with a periodic change of the refractive index, which results in pronounced photonic stop bands in the visible light range. By changing the diameter of the polystyrene microspheres, the position of the photonic stop band can be tuned through the visible spectrum. This developed methodology can be used as blueprint for the synthesis of various OHP films that could eventually be used as more effective light harvesting materials for diverse applications.

Honeycomb porous films of pentablock copolymer on liquid substrates via breath figure method and their hydrophobic properties with static and dynamic behaviour

The peeled film obtained on the isopropanol substrate through breath figure method exhibits the best hydrophobic properties, and the water droplet impact behavior shows an obvious rebound tendency and a weak maximum spreading diameter.

Multiple interfaces in self-assembled breath figures

Progress in the breath figure method is reviewed by emphasizing the role of the multiple interfaces and the applications of honeycomb films in separation, biocatalysis, biosensing, templating, stimuli-responsive surfaces and adhesive surfaces.

Polystyrene with hydrophobic end groups: synthesis, kinetics, interfacial activity, and self-assemblies templated by breath figures

Polystyrenes with hydrophobic end groups are synthesized from a series of alkyl or fluorinated ATRP initiators to fine-tune the surface morphologies of honeycomb films prepared by the breath figure method.

Synthesis of polystyrene with cyclic, ionized and neutralized end groups and the self-assemblies templated by breath figures

Polymers with functional end groups are synthesized using a cyclic lactone ATRP initiator for honeycomb-patterned porous films by the breath figure method.

Facile synthesis of biomimetic honeycomb material with biological functionality

A microfluidic approach to a honeycomb-structure material based on the synergistic effects of polymer rapid precipitation, double emulsion templating, and internal effervescent salt decomposition is reported. The delicate honeycomb structure exhibits unique characteristics with an external nanopore membrane and internal multiple cavities. The biological functionality of the artificial structure is explored to serve as microcarriers for cell culture and drug release, indicating their attractive properties for potential biomedical applications.