An approach to construct displays based on magnetochromatic microcapsules with narrow size distribution has been proposed. These magnetochromatic microcapsules are fabricated by a microfluidic technology. The shell layer of the obtained microcapsule is composed of transparent photocurable ethoxylated trimethylolpropane triacrylate (ETPTA) resin while the core is formed by the aqueous droplet containing monodisperse magnetic nanospheres. The capsule size, shell thickness, and morphology can be easily controlled by the flow rates during the fabrication. In the multipixel array formed by these microcapsules, each microcapsule acts as an individual display unit. The nanospheres in the core droplet can be influenced by an external magnetic field, forming ordered structures which determine light diffraction; therefore, various distinct colors are observed according to the intensity of the external magnetic field. These microcapsules have the advantage of long time stability, viewing angle independence, and dynamic tunable optics.

Colloidal PbS quantum dots (QDs) with tunable photoemission throughout the near-infrared (NIR) region (ca. 750–1000 nm) were synthesized by a two-phase approach. Here, oil-soluble lead oleate formed by a reaction of lead acetate and oleic acid (OA, the capping agent) in n-decane at 130 °C was used as lead precursor, and water-soluble Na₂S, thioacetamide (TAA), and thiourea, each having a different reactivity, were used as sulfur sources. When an n-decane solution of lead precursor and an aqueous solution of sulfur precursor were mixed at the appointed temperature, oil-soluble, near-infrared-emitting PbS QDs were achieved. In this study, we investigated the influence of the reactivity of water-soluble sulfur sources on the synthesis of PbS QDs. The morphology and crystal structure of the as-prepared PbS QDs were characterized by (high-resolution) transmission electron microscopy (TEM), selected area electron diffraction (SAED), and X-ray diffraction (XRD).

In this article, a new method for simultaneous determination of six phthalate esters was developed by a combination of electrospun nylon6 nanofibers mat-based solid phase extraction with high performance liquid chromatography-ultraviolet detector (HPLC-UV). The six phthalate esters were dimethyl phthalate (DMP), diethyl phthalate (DEP), butyl benzyl phthalate (BBP), di-n-butyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP) and dioctyl phthalate (DOP). Under optimized conditions, all target analytes in 50 mL environmental water samples could be completely extracted by 2.5 mg nylon6 nanofibers mat and eluted by 100 µL solvent. Compared with C18 cartridges solid phase extraction, C18 disks solid phase extraction and national standard method (China), nylon6 nanofibers mat-based solid phase extraction was advantageous in aspects of simple and fast operation, low consumption of extraction materials and organic solvents. The four methods were applied to analysis of environment water samples. All the results indicated that the determination values of target compounds with the proposed method were consistent with C18 cartridges and C18 disks solid phase extraction method, and the new method was better than the national standard method in aspects of recovery, LOD and precision. Therefore, nylon6 nanofibers mat has great potential as a novel material for solid phase extraction.

A novel hydrogel suspension array, which possesses the joint advantages of quantum-dot-encoded technology, bioresponsive hydrogels, and photonic crystal sensors with full multiplexing label-free DNA detection capability is developed. The microcarriers of the suspension array are quantum-dot-tagged DNA-responsive hydrogel photonic beads. In the case of label-free DNA detection, specific hybridization of target DNA and the crosslinked single-stranded DNA in the hydrogel grid will cause hydrogel shrinking, which can be detected as a corresponding blue shift in the Bragg diffraction peak position of the beads that can be used for quantitatively estimating the amount of target DNA. The results of the label-free DNA detection show that the suspension array has high selectivity and sensitivity with a detection limit of 10⁻⁹ M. This method has the potential to provide low cost, miniaturization, and simple and real-time monitoring of hybridization reaction platforms for detecting genetic variations and sequencing genes.

Photonic crystal (PC) based bioassay techniques have many advantages in sensitive biomolecular screening, label-free detection, real-time monitoring of enzyme activity, cell morphology research, and so on. This study provides an overall survey of the basic concepts and up-to-date research concerning the very promising use of PC materials for bioassays. It includes the design and application of PC films, PC microcarriers, PC fibers, and PC optofluidics for fluorescence enhancement or label-free bioassays. Emphasis is given to the description of the functional structures of different PC materials and their respective sensing mechanisms. Examples of detecting various types of analytes are presented. This article promotes communication among chemistry, biology, medicine, pharmacy, and material science.

A microfluidic system is designed to fabricate polymer dispersed liquid crystal microspheres, whose shape, surface smoothness, and size are controlled. A microlens array (MLA) is constructed by the assembly of the monodispersed microspheres. In the MLA, each microsphere acts as a separate imaging unit. As the liquid crystal (LC) used is a mixed liquid crystal that contain photoresponsive 4-butyl-4-methoxyazobenzene, the imaging capability and light transportation of the MLA can be reversibly controlled by light irradiation.

Negatively charged gold nanoparticles (AuNPs) and a polyelectrolyte (PE) have been assembled alternately on a polystyrene (PS) colloid by a layer-by-layer (LBL) self-assembly technique to form three-dimensional (Au/PAH)₄/(PSS/PAH)₄ multilayer-coated PS spheres (Au/PE/PS multilayer spheres). The Au/PE/PS multilayer spheres have been used to modify a boron-doped diamond (BDD) electrode. Cyclic voltammetry is utilized to investigate the properties of the modified electrode in a 1.0 M KCl solution that contains 5.0 × 10⁻³ M K₃Fe(CN)₆, and the result shows a dramatically decreased redox activity compared with the bare BDD electrode. The electrochemical behaviors of dopamine (DA) and ascorbic acid (AA) on the bare and modified BDD electrode are studied. The cyclic voltammetric studies indicate that the negatively charged, three-dimensional Au/PE/PS multilayer sphere-modified electrodes show high electrocatalytic activity and promote the oxidation of DA, whereas they inhibit the electrochemical reaction of AA, and can effectively be used to determine DA in the presence of AA with good selectivity. The detection limit of DA is 0.8 × 10⁻⁶ M in a linear range from 5 × 10⁻⁶ to 100 × 10⁻⁶ M in the presence of 1 × 10⁻³ MAA.