Preferential formation of stereocomplex crystals in poly(L-lactic acid)/poly(D-lactic acid) blends by a fullerene nucleator.

Selective formation of stereocomplex (sc) crystallization in enantiomeric poly(L-lactic acid)/poly(D-lactic acid) (PLLA/PDLA) blends is considered as one of the most effective and promising way to improve the mechanical and thermal properties of polylactide (PLA) materials. However, homocrystallization (hc) prevails over sc crystallization in high-molecular-weight (HMW) PLLA/PDLA blends. Herein, we propose a simple and straightforward approach for fabricating sc crystallization and suppress hc crystallization for HMW PLLA/PDLA blends through the addition of C70 as a nucleator. Non-isothermal crystallization and wide-angel X-ray diffraction studies demonstrate that, the incorporation of 1 wt% C70 overwhelmingly leads to the formation of sc crystallites, while preventing the formation of hc crystallites. Isothermal crystallization experiments at 140 °C reveal a significant reduction in the half-crystallization period of the PLLA/PDLA blend upon the addition of C70. Fourier-transformed infrared spectroscopy suggests that, the improved intermolecular interactions between PLLA and PDLA chains, as well as the inhibition of molecular chain diffusion and mobility, contribute to the accelerated formation of sc facilitated by C70. The enhanced sc crystallization results in a 15.5 °C higher thermal stability in the as-prepared PLLA/PDLA blend with 1 wt% C70 compared to the neat counterpart.

A near-infrared fluorogenic probe for nuclear thiophenol detection.

Based on the thiolysis of dinitrophenyl ethers, a nucleus-targeted fluorescent probe, AQD, with bisalkylaminoanthraquinone as the fluorophore, was prepared for the near-infrared mapping of thiophenol in live cells, zebrafish, and mice.

Cobalt oxide loaded graphitic carbon nitride as adsorptive photocatalyst for tetracycline removal from aqueous solution.

The treatment of antibiotic-containing wastewater is of great importance due to the potential threats of antibiotics to human and the ecosystem. We reported the preparation of cobalt oxide loaded graphitic carbon nitride (CoO/g-C3N4) by an impregnation-calcination method for tetracycline (TC) removal from aqueous solution. The developed CoO/g-C3N4 exhibited high adsorption capacity and fast adsorption kinetic for TC due to the complexation of TC with surface loaded CoO. In particular, 7%CoO/gC3N43 sample presented a maximum TC adsorption capacity of 391.4 mg g-1. It was found that Langmuir and pseudo-second order kinetic models fitted TC adsorption process well. Further photocatalytic studies showed that CoO loaded g-C3N4 was active for TC photodegradation, although the photocatalytic reaction rate constant was lower than that of native g-C3N4. CoO nanoparticles loading on g-C3N4 played the major role of adsorption sites rather than cocatalyst for photocatalysis. We believe that the developed CoO/g-C3N4 could be a potential adsorptive photocatalyst for antibiotic pollutants removal from wastewater.

Two-photon imaging of formaldehyde in live cells and animals utilizing a lysosome-targetable and acidic pH-activatable fluorescent probe.

Lyso-TPFP presents lysosomal targetability and an acidic pH-activatable response toward formaldehyde. Thus, it exclusively visualizes lysosomal formaldehyde and is immune against it in neutral cytosol and other organelles. In addition, two-photon fluorescence imaging endows Lyso-TPFP with the capability of in situ tracking formaldehyde in live cells and animals.

Simultaneous Fluorescence and Chemiluminescence Turned on by Aggregation-Induced Emission for Real-Time Monitoring of Endogenous Superoxide Anion in Live Cells.

Biological sensors with simultaneous turn-on signals of fluorescence (FL) and chemiluminescence (CL) triggered by one single species are supposed to integrate spatiotemporally resolved FL imaging with dynamic CL sensing into one luminescent assay. Efficiently increased accuracy can be expected based on complementary information simultaneously obtained from two independent modes, which is crucial in disease detection and diagnosis. However, very few examples can be found to date because of the key challenges in the rational design of sensing structures. Herein, aggregation-induced emission (AIE) was employed to develop a novel organic platform TPE-CLA with simultaneous turn-on FL/CL signals specifically modulated by O2•- in cells, which can be attributed to the activation of AIE resulted from the decreasing solubility after recognition. Using imidazopyrazinone (CLA) as the reactive motif and tetraphenylethene (TPE) as FL/CL enhancing skeleton, TPE-CLA is sensitive enough to image native O2•- in Raw264.7 cells and lipopolysaccharide stimulated O2•- in mice. Endogenous O2•- in HL-7702 cells induced by acetaminophen (APAP) was uninterruptedly monitored for 7200 s with CL and the results were further confirmed by FL imaging. Accordingly, TPE-CLA turns out to be a reliable candidate for real-time and continuous monitoring of endogenous O2•- in live cells. The strategy utilizing AIE to accomplish the FL/CL dual detection is expected to extend the application of AIE as reaction-activated biosensors.

Fluorescent Probe Based on Azobenzene-Cyclopalladium for the Selective Imaging of Endogenous Carbon Monoxide under Hypoxia Conditions.

Carbon monoxide (CO), a crucial gas message molecule, plays an important role in the regulation of physiological and pathological process. Hypoxia-induced CO is involved in modulating various cellular activities, including signal transduction, proliferation, and apoptosis. However, tracking CO fluctuation in the hypoxic cells is still a challenge due to lack of straightforward, visualized, and noninvasive tools. In this work, based on metal palladium-catalyzed reaction, we present the rational design, synthesis, and biological utility of an azobenzene-cyclopalladium-based fluorescent probe, ACP-2, for CO monitoring. ACP-2 exhibits capacity of detecting CO in aqueous buffer solution and live cells with high sensitivity and specificity. Utilizing ACP-2, we displayed a direct and visual evidence of endogenous CO up-regulation in live cells induced by hypoxia. Moreover, CO up-regulation during oxygen-glucose deprivation/reperfusion (OGD/R) was also imaged and certified by ACP-2.

Characterization of hollow hydroxyapatite/copper microspheres prepared from the reduction of copper-modified hydroxyapatite by glucose.

This study employed a co-precipitation method to synthesize copper-modified hydroxyapatite (HA) powders, where Cu(2+) ions had entered the structure of HA and occupied Ca(1) sites in the columns parallel to the c-axis. Through a hydrothermal treatment, hollow HA/copper (Cu(2)O and/or Cu) microspheres with core-shell structures were prepared in solutions containing glucose, sodium carbonate and sodium citrate. When prolonging the reduction time, Cu(2+) ions dissolved from copper-modified HA were reduced by glucose initially to Cu(+) ions and then to Cu atoms, which would precipitate as copper on the surface of HA. The formation of microspheres with hollow structures was explained by the Kirkendall effect which states that diffusion behaviors of ions were different for HA and copper precipitations. Hybrid HA/copper powders might find their applications in gas sensors, catalysts, electrodes and so on.

Highly luminescent water-soluble CdTe nanowires as fluorescent probe to detect copper(II).

Highly luminescent water-soluble CdTe nanowires synthesized in one step were used to detect copper(II) selectively below 0.078 microM in the presence of other physiologically relevant cations.

A surfactant-free route to single-crystalline CeO2 nanowires.

A surfactant-free route was successfully established to synthesize CeO2 single-crystalline nanowires using H2O2 as oxidizer and template agent.

Hydrothermal synthesis of ultralong and single-crystalline Cd(OH)2 nanowires using alkali salts as mineralizers.

Ultralong and single-crystalline Cd(OH)(2) nanowires were fabricated by a hydrothermal method using alkali salts as mineralizers. The morphology and size of the final products strongly depend on the effects of the alkali salts (e.g., KCl, KNO(3), and K(2)SO(4) or NaCl, NaNO(3), and Na(2)SO(4)). When the salt is absent, only nanoparticles are observed in TEM images of the products. The 1D nanostructure growth method presented herein offers an excellent tool for the design of other advanced materials with anisotropic properties. In addition, the Cd(OH)(2) nanowires might act as a template or precursor that is potentially converted into 1D cadmium oxide through dehydration or into 1D nanostructures of other functional materials (e.g., CdS, CdSe).