A novel Pt/C‐catalyzed transfer hydrogenation reaction of p‐benzoquinone to produce p‐hydroquinone using cyclohexanone as an unexpectedly effective hydrogen source

A new method for the production of p‐hydroquinone via a Pt/C‐catalyzed reduction of p‐benzoquinone is developed. Different from the conventional transfer hydrogenation reactions that usually use secondary alcohols such as isopropanol as the hydrogen source, in this work, it is unexpectedly found that cyclohexanone is a more effective hydrogen source than secondary alcohols, even cyclohexanol. This reaction affords acceptable yields of p‐hydroquinone with very high turnover number (1109) of the Pt/C catalyst. A mechanism of this interesting reaction is proposed on the basis of the results of a series of control experiments, GC–MS analysis as well as dynamic studies.     

An unexpected generation of magnetically separable Se/Fe3O4 for catalytic degradation of polyene contaminants with molecular oxygen

Selenization of Fe₂O₃ with NaHSe led to Se/Fe₃O₄. The unexpected generation of Fe₃O₄ attributed to the reduction conditions of the reaction, and the resulted magnetic features of the material facilitated its separation in practical applications. Owning to the synergistic effect of Se with Fe, the material was especially active to catalyze the oxidative C=C scission using O₂ as mild oxidant. The technique has been successfully applied in polyene degradation project, which is of profound practical values for the treatment of the polyene pigment pollution and may be applied in the food and pharmaceutical industry.     

Inhibition of mycotoxin deoxynivalenol generation by using selenized glucose

Selenized glucose can be easily prepared via the selenization reaction of glucose using in situ generated NaHSe as the selenization reagent. The technique has been industrialized to produce the chemical in kilogram scale, making it an easily available material in laboratory presently. The selenized glucose may be widely used as the starting material for the preparation of selenium-containing catalysts, as the organoselenium additive for feeds, and as the efficient selenium-enriched foliar fertilizers. In this work, we found that treating Fusarium graminearum, a fungal pathogen inciting wheat scab disease, with selenium glucose could significantly inhibit the generation of the deoxynivalenol (DON) toxin, which might be a breakthrough for reducing the detriment of the wheat scab disease.     

Synthesis of selenium-doped carbon from glucose: An efficient antibacterial material against Xcc

Se/C as a novel carbon-based biomaterial was prepared by using cheap and abundant glucose as the carbon source. It was highly active and could well restrain Xanthomonas campestris pv. campestris (EC₅₀ = 4.7403 μg/mL), a very harmful germ causing the devastating cabbage black rot disease and resulting in huge economic losses. As a type of carbon material insoluble in water, Se/C is bio-compatible and can adhere onto the leaves of the plants to allow a slow and sustained release of its efficacy, affording an efficient method for the cabbage black rot disease prevention and cure. This work as the first report on the bioactivity studies of Se/C significantly expands the application scopes of the selenium-containing materials and may draw continuous attentions from a broad field.     

Cell microarray chip system for accurate,rapid diagnosis and target treatment of breast cancer cells SK-BR-3

Biometrics probe is a molecule that specifically interacts with a specific target molecule and can be detected by a specific method. Three-dimensional (3D) embedded cell scaffold in the cell array chip can affect culture cancer cells in a 3D environment with continuous medium supplementary and help controlling the diffusion of small molecules drugs. Based on modification of DNA segment, this type of cell micro-array chip is a new biochip technology with convenient focusing and high throughput screening.     

One-pot synthesis of silver colloid with body-heat for surface-enhanced Raman spectroscopy detections

In this study, a convenient method of preparing the substrate is proposed with one-pot synthesis of silver colloid under body heat, and the SERS detection uses the fresh substrate to avoid the drawback of substrates' short life of use. The synthesis of silver colloid is carried out in a 10 mL vial by using ascorbic acid as a reductant and trisodium citrate as a stabilizer. The vial is grasped with the palm of the experimenter for several minutes without shaking. The proposed method is simple, rapid, green energy and cost-effective. By adjusting the concentration of trisodium citrate, not only the particle size can be controlled from about 110 nm to 50 nm but also the homogeneity of nanoparticles can be improved. As a SERS substrate, the silver colloid has high batch reproducibility and showed good SERS activity. The relative standard deviation between different manufacturers is 5.51% when the substrate of silver colloid is used for the detection of rhodamine 6 G. Using the substrate, the lowest detection concentrations of rhodamine 6 G, crystal violet, enrofloxacin, melamine and leucomalachite green are 1.0×10~(-8), 6.1×10~(-8),1.4 × 10~(-6), 7.1 ×10~(-5) and 5.1 ×10~(-8) mol/L, respectively. Results demonstrate that the developed method has the advantage of convenience and high efficiency in the field preparation of reliable SERS substrate.     

Turning coordination environment of 2D nickel-based metal-organic frameworks by π-conjugated molecule for enhancing glucose electrochemical sensor performance

The design and synthesis of the high-efficiency electrochemical sensor is the key to electrochemical conversion technology. This work synthesized Ni-based metal-organic framework (Ni-MOF) nanosheets by a competitive double ligands hybridization strategy. They were used as precursors to construct Ni-MOF@Ni-2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) core@shell structures by introducing π - conjugated molecule, HHTP. EXAFS further confirmed the interaction between Ni atoms and hexahydroxytriphenylene molecules. This process helps to promote more exposure of its active sites and enhance its electrochemical performance to become a high-performance enzyme glucose sensor. After coating, glucose detection sensitivity increased from 139.82 to 2124.90 μA/(mM cm²). These findings lay the foundation for preparing two-dimension hybrid functional MOF materials.     

Preparation of H-mordenite/MCM-48 composite and its catalytic performance in the alkylation of toluene with <Emphasis Type="Italic">tert</Emphasis>-butanol

A series of HM/MCM-48 samples with different SiO₂/Al₂O₃ molar ratio were prepared by sol-gel method. The prepared catalysts were characterized by XRD, N₂ adsorption-desorption, NH₃-TPD, FT-IR, SEM, and TEM techniques, and their catalytic performance was investigated in alkylation of toluene with tert-butanol. The adsorption capacity and the acid sites amount of HM/MCM-48-4 sample prepared by growing MCM-48 on the surface of HM zeolite are much higher than that of their mechanical mixture (HM/MCM-48(4) sample) due to its biporous structure; it shows higher catalytic performance than other HM/MCM-48 samples. The influence of reaction conditions on the catalytic performance of HM/MCM-48-4 zeolite was discussed. Toluene conversion of 41.4% and p-tert-butyltoluene selectivity of 73.5% were obtained at the weight ratio of toluene to HM/MCM-48-4 of 5, reaction temperature of 453 K, reaction time of 5 h and the molar ratio of toluene to tert-butanol of 0.5.     

Solid-phase extraction coupled with ultraviolent diffuse reflectance spectroscopy to fulfill sensitive and selective determination of phosgene

A simple, rapid, sensitive, and selective method was proposed to detect phosgene by solid-phase extraction coupled with ultraviolent diffuse reflectance spectroscopy. First, phosgene reacts with aniline solution to produce N,N′-diphenylcarbamide, then nylon membrane was selected as solid-phase material to enrich N,N′-diphenylcarbamide and separate it from mixture solution. At last, nylon membrane-concentrated N,N′-diphenylcarbamide was measured directly to collect ultraviolent diffuse reflectance spectrum without any elution. Some parameters such as membrane pore, vacuum degree, and volume of sample were optimized. Under the optimal conditions, the relationship between the mass x of phosgene and absorbance y at 257?nm was described in a linear equation of y?=?0.0141x?+?0.0025 with a squared correlation coefficient of 0.9920, the limit of detection of phosgene was estimated as low as 0.2466?µg. The developed method was evaluated by applying to detect phosgene content in real samples and comparing with aniline in ultraviolet spectrophotometric method, which is adopted by the standard method of China. The relative errors of two methods were between ?7.03% and 3.60%, and the relative standard deviations were from 6.55% to 9.31%, which are comparable to the standard method and verified the feasibility of the current method. These results demonstrated that the proposed method could be applied to the detection of phosgene with good accuracy and precision.     

A highly enantioselective organocatalyst for the Michael addition of cyclic ketones to nitroolefins

Enantiomerically pure triamine 2, which catalyses the Michael addition of cyclic ketones to nitroolefins with high diastereoselectivity (up to 99:1) and enantioselectivity (up to 91% ee), was designed and prepared.