Novel sponge-like molecularly imprinted mesoporous silica material for selective isolation of bisphenol A and its analogues from sediment extracts

Bisphenol A (BPA) imprinted sponge mesoporous silica was synthesized using a combination of semi-covalent molecular imprinting and simple self-assembly process. The molecularly imprinted sponge mesoporous silica (MISMS) material obtained was characterized by FT-IR, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption–desorption measurements. The results show that the MISMS possessed a large specific surface area (850.55 m² g⁻¹) and a highly interconnected 3-D porous network. As a result, the MISMS demonstrated a superior specific adsorption capacity of 169.22 μmol g⁻¹ and fast adsorption kinetics (reaching equilibrium within 3 min) for BPA. Good class selectivity for BPA and its analogues (bisphenol F, bisphenol B, bisphenol E and bisphenol AF) was also demonstrated by the sorption experiment. The MISMS as solid-phase extraction (SPE) material was then evaluated for isolation and clean-up of these bisphenols (BPs) from sediment samples. An accurate and sensitive analytical method based on the MISMS–SPE coupled with HPLC–DAD has been successfully established for simultaneous determination of five BPs in river sediments with detection limits of 0.43–0.71 ng g⁻¹ dry weight (dw). The recoveries of BPs for lyophilizated sediment samples at two spiking levels (50 and 500 ng g⁻¹ dw for each BP) were in the range of 75.5–105.5% with RSD values below 7.5%.     

大气压下甲烷火花放电制乙炔和合成气

用大气压下火花放电方法和发射光谱原位诊断技术, 对CH₄直接转化制乙炔和间接转化制合成气进行了研究, 并与介质阻挡放电进行了比较。结果表明, 火花放电具有能量效率高的突出优点, 能够高效地将CH₄活化成C原子、H原子和C₂等活泼物种。当CH₄单独进料时, 能得到以C₂H₂为主的烃类产物。当CH₄与CO₂和O₂共进料时, 能得到H₂/CO比值可调的合成气产物。在用火花放电转化CH₄和CO₂制合成气时, 添加O₂能够避免反应器的结炭问题, 反应温度只需225 ℃, 与常规催化法相比具有明显的低温优势。     

Structural,Electronic and Optical Properties of the Monoclinic α-CoV_2O_6

First-principles calculations based on density functional theory are performed to investigate the structural,electronic and optical properties of monoclinic α-Co V2O6.Firstly,the geometry structures obtained by geometry optimization are consistent with the experimental values.Then,the energy band structure is studied using both GGA and GGA+U methods.It is found that the on-site Coulomb repulsion of the Co 3d orbital plays a key role in describing the electronic properties of α-Co V2O6,and is necessary to open the energy band gap.According to the partial density of states(PDOS),significant Co–O and V–O hybridizations are observed in the valence and conduction bands,respectively.Furthermore,the Co–O and V–O bonds are found to have significant covalent characters.Below the absorption threshold ~1.9 e V,no absorption can be detected.However,there exists a strong and wide absorption band in the energy range from 1.9 to 11 e V.Such novel optical properties imply that the α-Co V2O6 may have some potential optical applications.     

Label-free immunosensor for monitoring vitellogenin as a biomarker for exogenous oestrogen compounds in amphibian species

A label-free, optical waveguide lightmode spectroscopy based immunosensor was developed for frog (Bombina orientalis) vitellogenin (Vtg) determination in biological samples as a biomarker for exogenous oestrogen compounds. Antibody against Vtg was produced in rabbits immunised with purified lipovitellin (Lpv), a precursor of Vtg, from the homogenised ovary of oriental fire-bellied toads (B. orientalis). The purified protein and Lpv/Vtg-specific serum were applied in both competitive and direct immunoassay formats using optical waveguide lightmode spectroscopy immunosensor. When measuring Vtg in direct manner, the Lpv antibody (1.76 µg mL^?1) was immobilised on the sensor surface, and the linear measuring range for Vtg was 0.1–10 µg mL^?1. During the competitive measurement, 100 ng mL^?1 Lpv was applied for the immobilisation. The linear measuring range for Vtg was 0.5–50 ng mL^?1. We studied the relative substrate specificity of the antibody, and it was concluded that the method is suitable for the sensitive and selective determination of Vtg levels in toads. Heart, liver and gonad samples from male animals were spiked with Vtg and were analysed using the newly developed method, and female toads and spawn samples were tested and compared to the calibration curve obtained by the spiked samples.     

Chiral Perylene Diimides: Building Blocks for Ionic Self‐Assembly

A chiral perylene diimide building block has been prepared based on an amine derivative of the amino acid L ‐phenylalanine. Detailed studies were carried out into the self‐assembly behaviour of the material in solution and the solid state using UV/Vis, circular dichroism (CD) and fluorescence spectroscopy. For the charged building block BTPPP, the molecular chirality of the side chains is translated into the chiral supramolecular structure in the form of right‐handed helical aggregates in aqueous solution. Temperature‐dependent UV/Vis studies of BTPPP in aqueous solution showed that the self‐assembly behaviour of this dye can be well described by an isodesmic model in which aggregation occurs to generate short stacks in a reversible manner. Wide‐angle X‐ray diffraction studies (WXRD) revealed that this material self‐organises into aggregates with π–π stacking distances typical for π‐conjugated materials. TEM investigations revealed the formation of self‐assembled structures of low order and with no expression of chirality evident. Differential scanning calorimetry (DSC) and polarised optical microscopy (POM) were used to investigate the mesophase properties. Optical textures representative of columnar liquid–crystalline phases were observed for solvent‐annealed samples of BTPPP. The high solubility, tunable self‐assembly and chiral ordering of these materials demonstrate their potential as new molecular building blocks for use in the construction of chiro‐optical structures and devices.     

BODIPY: A Highly Versatile Platform for the Design of Bimodal Imaging Probes

In molecular imaging, multimodal imaging agents can provide complementary information, for improving the accuracy of disease diagnosis or enhancing patient management. In particular, optical/nuclear imaging may find important preclinical and clinical applications. To simplify the preparation of dual‐labeled imaging agents, we prepared versatile monomolecular multimodal imaging probe (MOMIP) platforms containing both a fluorescent dye (BODIPY) and a metal chelator (polyazamacrocycle). One of the MOMIP was conjugated to a cyclopeptide (i.e., octreotide) and radiolabeled with ¹¹¹In. In vitro and in vivo studies of the resulting bioconjugate were conducted, highlighting the potential of these BODIPY‐based bimodal probes. This work also confirmed that the biovector and/or the bimodal probes must be chosen carefully, due to the impact of the MOMIP on the overall properties of the resulting imaging agent.     

Fe2BiTaO7纳米催化剂的组织结构及光催化性能

用固相反应合成法合成了光催化剂Fe2BiTaO7,通过XRD、SEM、TEM、紫外-可见漫反射等表征方法对其组织结构及光催化性能进行了研究。结果表明Fe2BiTaO7为立方晶系烧绿石结构,空间群为Fd3m,禁带宽度为1.72 e V。通过比较Fe2BiTaO7、P25TiO2、掺氮Ti O2和Bi2In Ta O7的可见光光催化降解罗丹明B,发现Fe2BiTaO7降解效果及催化活性均高于其它催化剂,并且Fe2BiTaO7降解罗丹明B效率是掺氮二氧化钛的1.5倍。Fe2BiTaO7降解罗丹明B的曲线符合一级动力学,一级动力学常数为0.022 93 min-1。研究了罗丹明B可能的降解路径和Fe2BiTaO7在可见光下降解苯酚的效果。Fe2BiTaO7(可见光)光催化剂系统适用于纺织工业废水处理。     

钴( Ⅱ)与1,3-间苯咪唑及间苯二甲酸根构筑的两个配位聚合物的合成、晶体结构及性质

以间苯咪唑(1,3-bib)和间苯二甲酸(H2MPA)为配体,在温和的水热条件下,合成了Co( Ⅱ)的2个配位聚合物{[Co(1,3-bib)(MPA)(H2O)2]·H2O}n(1)和{[Co2(1,3-bib)2(MPA)2]·5H2O}n(2),分别用X-射线单晶衍射、元素分析、IR和热重等手段对它们进行了表征,结果表明,配位聚合物1为1D层状结构,属于正交晶系,Pnma空间群;配位聚合物2为双核2D结构,属于三斜晶系,P1空间群。在室温下研究了它们的光学性质。     

聚苯胺共价修饰的氧化石墨烯的合成及其光限幅性能

利用酰胺化反应将聚苯胺(PANI)共价接枝到氧化石墨烯(GO)的表面,得到的杂化材料GO-PANI能很好地分散在常见的有机溶剂中。样品的XPS谱和红外光谱数据证实了在GO和PANI之间存在酰胺键。在316nm激光激发下,PANI和GO-PANI分别在420nm和416nm处显示出很强的荧光峰。GO-PANI的最大发射峰相对于PANI的发射峰蓝移了4nm,且荧光强度增强。开孔Z-扫描实验结果表明:与PANI相比,GO和PANI的共价键合使材料在532nm激光辐照下表现出更大的非线性消光系数和三阶非线性极化率虚部值,光限幅性能明显增强。     

Influence of multiwall carbon nanotube (MWCNT) dispersion on ignition of poly(dimethylsiloxane)–MWCNT composites

Poly(dimethylsiloxane) (PDMS) filled with low contents of multiwall carbon nanotubes (MWCNT) was prepared using different ways to monitor the dispersion of MWCNT. The influence of the dispersion on thermal conductivity and transmittance was measured. High degree of transparence can be achieved with 0.02 phr of well dispersed MWCNT. Time‐to‐ignition (TTI) was also measured on 2‐ or 4‐mm‐thick specimens heated using radiative unidirectional source. Time‐to‐ignition was found to decrease with the incorporation of MWCNT because more heat is absorbed at the surface. Higher time‐to‐ignition was observed for partially translucent composites, due to different absorption in‐depth profiles. It can be assumed that time‐to‐ignition can be controlled by the dispersion of MWCNT into the polymeric matrix. Copyright © 2015 John Wiley & Sons, Ltd.