Design of double-core-shell structural materials for the extraction of non-steroidal anti-inflammatory drugs.

In this work, core-shell material with a special structure was designed and applied in solid-phase extraction (SPE) for non-steroidal anti-inflammatory drugs (NSAIDs) combined with high-performance liquid chromatography. Based on the advantages of core-shell ZIF-8@ZIF-67 (Zeolite imidazole ester framework materials [ZIFs]), effective derivatization treatment was carried out to partially vulcanize the original ZIFs, resulting in a special and new double-core-shell structural material CoS/ZIF-67/ZnS/ZIF-8 (ZIFs@ZnS@CoS) with porous surface and center hollow. The multiple forces caused by the rich chemical structure, the large specific surface area caused by the special pore structure, and the effective protection of the ZIFs core by sulfide shell make the designed material have higher extraction efficiency and longer service life, compared with ZIF-8@ZIF-67 and ZIF-8. At the same time, the established analytical method for non-steroidal drugs had a high recovery rate (98.93%-102.10%), low detection limit (0.11-0.27 µg/L), and wide linear range (1-200 µg/L) within a good correlation coefficient R2 (0.9978-0.9993). Satisfactory results were also obtained from the extraction of NSAIDs from the Yellow River water samples. These results indicate that the designed double-core-shell structure material can effectively exert its structural advantages and become a promising extraction material.

Alien species water hyacinth realizes waste into treasure: The preparation of biomass sorbent to determine benzoylurea insecticides in tea products.

A fast and effective analytical method with biomass solid-phase microextraction sorbent combined with a high-performance liquid chromatography-ultraviolet detector was proposed for the determination of benzoylurea (BU) insecticides in tea products. The novel sorbent was prepared by activating and then carbonizing water hyacinth with a fast growth rate and low application value as raw material and showed a high specific surface area and multiple interactions with analytes, such as electrostatic action, hydrogen bonding, and π-π conjugation. After optimizing the three most important extraction parameters (pH [X1], sample loading rate [X2], and solution volume [X3]) by Box-Behnken design, the as-established analytical method showed good extraction performance: excellent recovery (80.13%-106.66%) and wide linear range (1-400 µg/L) with a determination coefficient of 0.9992-0.9999, a low limit of detection of 0.02-0.1 µg/L and the satisfactory practical application results in tea products. All these indicate that the water hyacinth-derived material has the potential as a solid-phase extraction sorbent for the detection and removal of BU insecticides from tea products, and at the same time, it can also achieve the effect of rational use of biological resources, maintaining ecological balance, turning waste into treasure, and achieving industrial production.

Two-Dimensional Nanosheet-Enhanced Waterborne Polyurethane Eutectogels with Ultrastrength and Superelasticity for Sensitive Strain Sensors.

Sensing materials that are ultrastrong but still superelastic and highly sensitive are crucial for meeting the requirements of future flexible sensors. However, these requirements are challenging to satisfy simultaneously due to the internal constraints among these properties. Here, an ultrastrong and superelastic eutectogel is designed and prepared using a waterborne polyurethane (WPU) network enhanced by two-dimensional (2D) nanosheets in a deep eutectic solvent. The 2D nanosheet-induced noncovalent cross-linking endows the prepared eutectogel with superelasticity and flexibility, and its elongation at break reaches 2071%, higher than those of most polymers (<1000%). Meanwhile, this eutectogel also exhibits a high tensile strength (21.6 MPa), which is strong enough to support 20 000 times its own weight. Such a composite design provides a feasible route for preparing eutectogels with outstanding comprehensive functions without trade-offs among these features. In addition, the eutectogel-assembled sensor possesses a high ionic conductivity of 0.225 S/m and a high strain sensitivity of 1.18 kPa-1. Furthermore, it can be integrated into the sensing arrays for multidimensional signal monitoring without diminishing its pristine strength and flexibility. Surprisingly, the eutectogel can be quickly disintegrated in ethanol due to the WPU's pseudoplastic behavior, providing a competitive way to dispose of waste electronic devices.

Fabrication of Fe3O4@Polydopamine@Bovine Serum Ablumin (BSA) and Fe3O4@Polydopamine-Ag Core-Shell Nanoparticles and Their Catalytic and Antibacterial Properties.

The submicron-sized Fe3O4 particles were synthesized by solvothermal method. Then polydopamine (PDA) was used to modify the surface of Fe3O4 particles. And then the core-shell Fe3O4@PDA@BSA (single layer and multilayer) microspheres were prepared by the layer by layer self-assembly method (SAM). In addition, Ag nanospheres were grafted onto the surface of Fe3O4@PDA particles to obtain Fe3O4@PDA-Ag core-shell nanoparticles using silver mirror reaction. The morphology and component of the obtained core-shell particles were characterized by transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The biocompatibility of the microspheres was researched in vitro by MTT method and its magnetic properties were also evaluated. The results showed that the microsphere has excellent magnetic properties and good biological safety. Then the catalytic performance of Fe3O4@PDA-Ag microspheres for methylene blue (MB) was studied. And the antimicrobial properties of Fe3O4@PDA-Ag microspheres for Escherichia coli and Bacillus subtilis were also be discussed. The results indicated good catalytic properties and antibacterial properties.

Kinetic Determination of Lanthanum(III) by the Catalytic Effect on the Oxidation of Fluorescent Safranine Dyes with Potassium Bromate.

Two simple and sensitive kinetic-fluorometric methods have been developed for the determination of lanthanum(III): fluorescence quenching generated by the oxidation of safranine T or phenosafranine with potassium bromate in an acetate buffer solution. The rate of the oxidation reaction is significantly accelerated after adding lanthanum(III). A good linearity between the relative fluorescence intensity and lanthanum(III) is observed in the range of both 0.04 - 2.0 and 4.0 - 16 µg/mL. The detection limits have been 3.6 × 10-3 and 0.334 µg/mL respectively. The accuracy and reliability of the methods are further validated by recovery studies via a standard-addition method, with percentage recoveries ranging from 98 to 102%. Comparing the results of two measured reaction systems, we find that the safranine T reaction system provides high sensitivity and a wider linear range. In consequence, we have chosen the safranine T system to detect sample water, and explored the reaction mechanism.

A highly thermal stable solid phase microextraction fiber prepared by an inorganic binder.

An easy method to prepare solid phase microextraction fibers by introducing an inorganic binder was demonstrated in this study, where MoS2 was selected as the extraction phase material because of its graphite-like layered structure with large specific adsorption area and good stability, and was then adhered to a stainless steel wire by acid aluminum phosphate binder with the spraying method. The as-prepared solid phase microextraction fiber coupled with gas chromatography was then used to extract some polycyclic aromatic hydrocarbons target analytes including the low-volatile benzo(a)pyrene etc. from a standard sample. Comparing with the MoS2-epoxy resin and commercial polyacrylate fibers, the MoS2-acid aluminum phosphate fiber has a higher thermal stability because of highly thermal stable acid aluminum phosphate, which is durable for a long service life at a high temperature (320 °C), and has the advantage in the extraction of low-volatility analytes. After the optimization of adsorption and desorption factors (ionic strength, adsorption time and temperature, and desorption temperature), method detection limits of <0.1 µg L(-1) were achieved, and the calibration curves were all linear (R(2) ≥ 0.9981) within the range of 0.1-100 µg L(-1). The satisfying repeatability was also achieved, the RSD values of single-fiber were 3.49-5.81%, and the ones of fiber-to-fiber were 5.32-7.22%. As a result, the present fiber with good thermal stability can work at high temperature for a long service life, which is useful for the detection of low-volatility target analytes in practical applications.

Template-directed preparation of bovine serum albumin microporous multilayer films.

The fabrication of polymeric materials with ordered submicron-size void structures is potentially valuable for many applications such as catalysts, separation and adsorbent media. This paper reports the preparation of macroporous protein multilayer films with regular voids using silica nanospheres as templates. Both monodisperse silica colloids and highly ordered assembly silica multilayer films are used as templates to prepare microporous bovine serum albumin multilayer films with ruleless and ordered submicron-sized voids. Glutaraldehyde is used as a crosslinking agent to form a firm net-like protein film on the surface of silica templates. The microporous protein film is obtained after removing of silica templates. Compare with polymer film, protein film has good biocompatibility and biodegradability which will be beneficial to its biological applications.

Preparation and biocompatibility of BSA monolayer on silicon surface.

This paper describes a general strategy for grafting protein molecules on silicon surface by using dopamine as adhesive layer. With this method, silicon surface had been successfully modified by BSA monolayer. Fourier transform infrared spectra, X-ray photoelectron spectroscopy, contact angle analysis and atomic force microscopy confirmed the sequential grafting of initiator and protein molecules. Cell adhesion experiments with PC-12 cells showed that the obtained monolayer exhibits good biocompatibility. The corrosion resistance behavior of the polydopamine and BSA modified silicon wafers was investigated by potentiodynamic test, which indicated that the modified surfaces exhibited a better anti-corrosion capability than silicon surface. All these results must be valuable for the application of protein monolayer in biological and biomedical technology.

The fabrication of hollow BSA micro/nanocapsules.

Biogenic micro/nanpocapsules, comprised of bovine serum albumin (BSA), were successfully prepared by depositing BSA multilayer on SiO2 particles followed by glutaraldehyde cross-linking and the removal of templates. Silica particles with two sizes, BMS (bimodal silica) and smaller silica particles with sizes of about 3 microm and 200 nm, respectively, are used. The BSA hollow microcapsules were characterized by transmission electron microscopy (TEM) and observed by confocal laser scanning microscopy (CLSM) after signed by fluorescein isothiocyanate (FITC). The as-prepared BSA hollow microcapsules are potentially valuable in biotechnology and medicament applications.

Long TiO2 hollow fibers with mesoporous walls: sol-gel combined electrospun fabrication and photocatalytic properties.

Long TiO2 hollow fibers with mesoporous walls have been fabricated with the sol-gel combined two-capillary spinneret electrospinning technique using a triblock copolymer (Pluronic, P123, (H(C2H5O)20(C3H7O)70 (C2H5O)20OH) as a pore-directing agent. The as-prepared hollow fibers were as long as 30 cm with an outer diameter of 0.1-4 microm and wall thickness of 60-500 nm. The diameters and wall thicknesses of the hollow fibers could be tuned by adjusting the electrospinning parameters. The fiber walls were composed of mesopores 6.7 nm in diameter as calculated from the N2 adsorption/desorption isotherm. The high-resolution TEM (HR-TEM) images exhibited that the mesopores were hexagonally aligned with a low order because of the curving of the pores. When comparing with other nanostructured TiO2 materials such as commercial TiO2 nanoparticles (P25, Degussa) and mesoporous TiO2 powders, the hollow fibers exhibited higher photocatalytic activities toward degradation of methylene blue and gaseous formaldehyde.