A one‐dimensional silver(I) coordination polymer based on the 2‐[2‐(pyridin‐4‐yl)‐1H‐benzimidazol‐1‐ylmethyl]phenol ligand exhibiting photoluminescence

A one‐dimensional Ag^I coordination complex, catena‐poly[[silver(I)‐μ‐{2‐[2‐(pyridin‐4‐yl)‐1H‐benzimidazol‐1‐ylmethyl]phenol‐κ²N²:N³}] perchlorate monohydrate], {[Ag(C₁₉H₁₅N₃O)]ClO₄·H₂O}_n, was synthesized by the reaction of 2‐[2‐(pyridin‐4‐yl)‐1H‐benzimidazol‐1‐ylmethyl]phenol (L) with silver perchlorate. In the complex, the L ligands are arranged alternately and link Ag^I cations through one benzimidazole N atom and the N atom of the pyridine ring, leading to an extended zigzag chain structure. In addition, the one‐dimensional chains are extended into a three‐dimensional supramolecular architecture via O—H...O hydrogen‐bond interactions and π–π stacking interactions. The complex exhibits photoluminescence in acetonitrile solution, with an emission maximum at 390 nm, and investigation of the thermal stability reveals that the network structure is stable up to 650 K.     

Sulfonated carbon catalyzed oxidation of aldehydes to carboxylic acids by hydrogen peroxide

Sulfonated carbon as a strong and stable solid acid catalyst exhibited excellent catalytic performance in various acid-catalyzed reactions. Here, sulfonated carbon, as catalyst for oxidation reaction, was prepared via the carbonization of starch followed by sulfonation with concentrated sulfuric acid. N₂ physisorption, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray fluorescence and acid-base titration were used to characterize the obtained materials. The catalytic activity of sulfonated carbon was studied in the oxidation of aldehydes to carboxylic acids using 30 wt% H₂O₂ as oxidant. This oxidation protocol works well for various aldehydes including aromatic and aliphatic aldehydes. The sulfonated carbon can be recycled for three times without obvious loss of activity.     

Polyhedral oligomeric silsesquioxanes as functional monomer to prepare hybrid monolithic columns for capillary electrochromatography and capillary liquid chromatography

A simple approach to fabricate hybrid monolithic column within the confines of fused-silica capillaries (75 μm i.d.) was introduced. A polyhedral oligomeric silsesquioxanes (POSS) reagent containing a methacrylate group was selected as functional monomer, and copolymerized with bisphenol A dimethacrylate (BPADMA) or ethylene dimethacrylate (EDMA) in the presence of porogenic solvents via thermally initiated free radical polymerization. After optimization of the preparation conditions, two POSS-containing hybrid monoliths were successfully prepared and exhibited good permeability and stability. By comparison of the separation efficiencies of the resulting poly(POSS-co-BPADMA) and poly(POSS-co-EDMA) monoliths in capillary electrochromatography (CEC) and capillary liquid chromatography (cLC), it was indicated the former has better column efficiencies for alkylbenzenes, phenols, anilines and PAHs in CEC and cLC than the latter. Particularly, the hybrid poly(POSS-co-BPADMA) monolith is more suitable for separation of PAHs due to π–π interaction between the analytes and aromatic rings in the surface of monolithic stationary phase.     

Open-sandwich immunoassay for sensitive and broad-range detection of a shellfish toxin gonyautoxin

At present, the analytical method for paralytic shellfish poisoning (PSP) toxins in shellfish is the mouse bioassay (MBA), which is an official method of the Association of Analytical Communities (AOAC [8]). However, the low sensitivity and concerns over the number of live animals required for testing have been cited as the major reason for seeking its replacement. In this report, we employed an open-sandwich immunoassay (OS-IA) to detect gonyautoxin (GTX2/3), a kind of PSP toxins. OS-IA, which utilizes the antigen-induced enhancement of antibody V_H/V_L interaction, can measure a small molecule antigen in a noncompetitive format. Hence it has a wider working range and shorter measurement time. We isolated anti-GTX2/3 antibody gene from a hybridoma GT-13A by screening a Fab-displaying phage library. Then the vectors for OS-IA were constructed, and examined for antigen concentration-dependency of the V_H/V_L interaction by OS-ELISA. As a result, in each case, signal intensity increases notably in a wide concentration range (0.1 to >1000 ng mL⁻¹) of free GTX2/3, which was enough to cover its regulation value (80 μg 100 g⁻¹) in many countries. So OS-IA will be widely applicable to detect PSP toxins in shellfish meats and in drinking water.     

One‐Pot Synthesis of CdSe Quantum Dots in Aqueous Solution for Biological Labeling

The one‐pot synthesis of water‐soluble and biologically compatible yellow CdSe quantum dots (QDs) featuring the use of glutathione (GSH) as the capping and reducing agent was achieved under aqueous conditions at 150 °C. The synthesized yellow CdSe QDs with quantum yield (QY) up to 20% exhibit zinc blende cubic structure particles with an average diameter of 4‐5 nm. It was found that both molar ratio of Se/Cd and reaction time had a significant effect on size distribution of GSH‐CdSe QDs. Meanwhile, the interaction of QDs bioconjugated to bovine hemoglobin (BHb) was studied by absorption and fluorescence(FL) spectra. With addition of BHb, the FL intensity of CdSe QDs largely quenched due to the static mechanism. The linear range is 5.0 × 10^?8 mol/L to 3.0 × 10^?6 mol/L, and the correlation coefficient is 0.9991, suggesting that could be used as a probe to label biological molecules and bacterial cells.     

Vitrifolin A: A Norlabdane Diterpenoid from the Fruits of Vitex trifolia Linn. var. simplicifolia Cham

A new norlabdane diterpenoid, named vitrifolin A, was isolated from the fruits of Vitex trifolia Linn. var. simplicifolia Cham. Its structure was elucidated by mean of spectroscopic methods, including HRESIMS, IR, 1D and 2D NMR. The inhibitory effect of vitrifolin A on nitric oxide production in lipopolysaccarideactivated mouse macrophages was also evaluated.     

A Novel One‐Pot Synthesis of UV‐Blue ZnSe Nanocrystals in Aqueous Solution

Described herein is a novel one‐pot aqueous synthesis of ZnSe nanocrystals has featuring the utilization of Na₂SeO₃ and Zn(AC)₂×2H₂O as Se and Zn source, glutathione (GSH) as stabilizing agent and reducing agent. By this approach, the UV‐blue ZnSe QDs with quantum yield (QYs) up to 19% have been synthesized with a molar ratio of Se/Zn/GSH at 1:4:8.5 under aqueous conditions at 110 °C. XRD and TEM show the ZnSe QDs are zinc cubic structure particles with an average diameter of 3–5 nm.     

Determined GA by FI‐CE in Luminol‐H2O2 System

It was found that the chemiluminescence arising from the reaction of luminol with H₂O₂ involving Co(II)‐catalyzed in alkaline solution could be strongly inhibited by gibberellic acid. Based on this observation, a new flow injection chemiluminescence method is proposed for the determination of gibberellic acid. The detection limits of the method are 0.09 ng mL^?1 gibberellic acid. The method was successfully applied to the determination of gibberellic acid in bacteria‐free culture liquid.