Smart electrochemical sensor for some neurotransmitters using imprinted sol-gel films

A hybrid sol-gel material formed by acid hydrolysis of a mixture of tetraethylorthosilicate (TEOS) and phenyltriethylorthosilicate (PTEOS) as functional monomers was imprinted by tyramine and dopamine as template molecules for the purpose of molecular recognition. Imprinted materials were spin coated as thin films on the surface of glassy carbon electrodes and then were characterized using cyclic voltammetry (CV). After extraction of the encapsulated molecules, imprinted films were tested in solutions of their templates and other molecules. Rebinding experiments were followed by electrochemical characterization using square wave voltammetry (SWV). Imprinted films showed higher affinities toward their template molecules compared to other structurally similar molecules especially for tyramine imprinted film. With the exception of tyramine and norepinephrine, the interference level did not exceed 5% for all compounds studied for dopamine-imprinted films. Tyramine-imprinted films however showed high affinity to tyramine with dopamine 40% interference. Some factors related to the rebinding ability process like pH of solution, concentration of template were studied. The sensing surface lifetime extended to 2 weeks with decay in response signal that ranged from 22%, 40% to 60% for dopamine, tyramine and norepinephrine, respectively. The standard deviation from the mean of measurements for the repeated experiments is 7.4%. Electrochemical impedance spectroscopy (EIS) measurements confirmed the results obtained by electrochemical measurements. Morphological characteristics of the imprinted thin films and their thickness were investigated using scanning electron microscope (SEM).     

Template‐Synthesized Porous Silicon Carbide as an Effective Host for Zeolite Catalysts

A facile method has been developed for the fabrication of porous silicon carbide (SiC) by means of sintering a mixture of SiC powder and carbon pellets at a relatively lower temperature, that is, 1450 °C, in air. The pore density and the total pore volume of the resulting porous SiC could be tuned by changing the initial SiC/C weight ratio. The structure evolution and the associated property changes during the preparation were examined through X‐ray diffraction, scanning electron microscopy, thermogravimetric analysis, ²⁹Si magic‐angle spinning (MAS) NMR spectroscopy, and mercury‐intrusion porosimetry analyses. Silica and SiO_xC_y ceramics formed in situ during the calcination process acted as binders of the porous SiC grains. The porous SiC can be used as a host for the growth of ZSM‐5 zeolite crystals to form the ZSM‐5/porous‐SiC composite material. After loading another catalytic active component of molybdenum, a novel catalytic material, Mo‐ZSM‐5/porous‐SiC, was obtained, which exhibited improved catalytic activity in the methane dehydroaromatization reaction.     

苯炔体系大环合成、自组装及其应用

含苯炔结构的大环(aryleneethynylenemacrocycle,AEMs)体系具有独特的性质和潜在的应用前景,在过去的数年中被广泛研究和探索。本文系统地介绍了AEMs的合成方法,包括不同关环方法、固相合成、模板合成和聚集驱动关环法等。在研究AEMs性质方面,重点介绍了它们的自组装性能。同时也介绍了AEMs在构造三维纳米结构、液晶、管状通道、主客体复合物等超分子化学领域的应用。     

六钨酸盐为模板的三维网状超分子化合物[La2(DNBA)4(DMF)8][W6O19]的合成和晶体结构

0 Introduction polyoxometalates (POMs), in addition to their im- portance in catalysis, biochemical separation and medicinal chemistry, play an important role for the design of new materials with novel electronic, magnet- ic and topological properties[1￣…     

模板固相合成磷酸铝及其表征

Ｔ－磷酸铝的合成用水热方法,需９５０℃,２０天才能得到［１］。研究结果表明用固相方法,１５０℃,２小时合成了Ｔ－磷酸铝,同样条件下有模板存在可以得到磷酸铝微晶和Ｔ－磷酸铝,用ＸＲＤ、ＩＲ、ＩＣＰ和化学分析方法对产物进行了表征。 磷酸铝是一类具有广而重要应用的材料,过去十多年里,应用模板在胶态介质中水热方法合成了具有微孔、小孔、中孔的一系列磷酸铝类材料。由于其具有多种结构和组成,对热和水热的稳定性,使得它们在吸附分离、催化剂及催化剂载体、土壤科学、污水处理、医药上调节胃酸等中起着重要作用。特别是在…     

Synthesis of nanostructured polymer materials with different morphologies: Nanoporous ordered networks and hollow capsules

Nanostructured polymer materials with interesting morphological variation, which include three dimensionally interconnected uniform nanoporous network arrays (volume- and surface-templated ordered arrays) and hollow core spheres were synthesized by inducing different polymerization process of phenol and formaldehyde as a precursor over silica templates (ordered silica colloidal crystals or individual silica particles). The pore sizes of the resulting nanostructured polymer materials can be easily controlled by monitoring the sizes of silica spheres, while their morphologies were modulated by controlling the initiation sites of the acid-catalyzed condensation reaction of the same polymer precursor and by modifying silica templates.     

脉冲激光沉积法制备的纳米硅薄膜的结构与光学性质

采用二次阳极氧化法,制备了多孔氧化铝模板。在真空背景下,用脉冲激光沉积法,在多孔氧化铝模板上沉积一层硅,制成了硅与多孔氧化铝的复合膜,然后用盐酸将多孔氧化铝模板完全腐蚀掉,制备均匀分布着硅纳米线的硅膜。用扫描电子显微镜、X射线衍射、光致发光对纳米硅的结构和光学性质进行了测试分析。结果表明:硅纳米线的直径约为67.5nm,长度约为100nm,数密度约10¹¹/cm²。光致发光谱是可见光范围内的一个宽发射峰,上面叠加了许多具有精细结构的尖峰,尖峰之间的波长间隔不相等,但能量间隔相等。分析了样品的结构特点,利用量子限制模型和表面发光中心模型对光谱进行了解释,提出了一个新的能级模型,求出了各个尖峰对应激发态能级的量子数。为探讨纳米硅的发光机制和实现硅发光器件的制备提供了实验依据。     

施主掺杂对BaTiO3钙钛矿半导体纳米晶光催化性能的影响

以沉淀法制备的Cu_2O为牺牲模板剂,采用水热法制备La施主掺杂的BaTiO_3钙钛矿半导体纳米晶,借助X射线衍射(XRD)、透射电子显微镜(TEM)、高分辨透射电镜(HRTEM)、X射线光电子能谱((XPS)、扫描电子显微镜(SEM)、紫外-可见漫反射光谱(UV-Vis DRS)表征La掺杂的BaTiO_3晶的物相、微观形貌及光催化性能。结果表明,La掺杂BaTiO_3构建了晶体缺陷,有效提高了BaTiO_3的光催化性能。当掺杂量为4%(w/w)时,样品的光催化性能最好,在可见光照射360 min后,对4-硝基苯酚溶液的降解率可达到93.2%。该催化剂5次循环后的活性仍然大于86.7%,表明La施主掺杂的BaTiO_3是一种有效的可见光催化剂。     

药物甲氧苄氨嘧啶分子模板聚合物膜的选择性结合及透 过性质研究

用分子印迹技术制备了对甲氧苄氨嘧啶具有特异结合和透过性质的膜状分子模板聚合物,Scatchard分析表明,在分子模板聚合物膜中存在一类等价的可与甲氧苄氨嘧啶结合的位点,该结合位点的平衡离解常数为Kd=4.85×10^-2mmol/L,甲氧苄氨嘧啶分子模板聚合物膜的选择性透过实验表明,在该聚合物膜中存在着由形状和功能基团均与模板分子甲氧苄氨嘧啶相互补的孔穴组成的通道,该通道可有选择性地通过模板分子。     

Synthesis and Ion Selectivity of Tetrakis[(N,N-dialkylaminocarbonyl) methoxy]homocalix[4]arenes

An attempted O-alkylation of the flexible macrocycle 1 withN,N-dialkylchloroacetamides in the presence of NaH, K₂CO₃ or Cs₂CO₃ gave only one pure stereoisomer 1,4-alternate-2a–c, while other possible isomers were not observed. In contrast, only an intractable mixture was obtained when Na₂CO₃ was used as base. The structural characterization of these products is discussed. The two-phase solvent extraction data indicated that tetrakis(N,N-dialkylaminocarbonyl) derivatives 2b–c show strong alkali metal cation affinity and the extractabilities are much higher than that for the corresponding calix[4]arene tetraethyl ester 4 and homocalix[4]arene tetraethyl ester 3. High Li⁺ and Na⁺ extractabilities were observed for tetrakis[(N,N-diethylaminocarbonyl) derivative 2b. However, no significant high ion selectivity for alkali metal cations was observed in tetraamide 2b. ¹H-NMR titration of tetraamide 2b with KSCN clearly demonstrates that a 1:1 complex is formed with retention of theoriginal symmetry to be conformationally frozen on the NMR time scale.