基于水溶性共轭聚合物的蛋白质检测*

近年来,以共轭聚合物作为生物传感元件,在生物大分子（如核酸、蛋白质）特异性识别、检测方面的研究越来越受到人们的关注。共轭聚合物具有强的光捕获能力,具有倍增光学响应性,可用来放大荧光传感信号,大大提高检测的灵敏度,为生物传感器的发展提供了新的传感模式。基于共轭聚合物的新型生物传感器在医疗诊断、环境检测以及国家安全防御等方面具有广泛的应用前景。本文简要介绍了共轭聚合物的荧光信号放大机制以及在蛋白质、酶、抗原－抗体检测方面的应用。最后对共轭聚合物在蛋白质检测方面的未来发展趋势进行了展望。     

荧光共轭聚合物在生物大分子检测中的应用*

共轭聚合物因其具有π-电子体系及共轭离域结构,一般都具有优异的发光性能,其发光强度和发射波长会随被检测化合物结构的不同而发生特异性响应,特别是在与被检测物相互作用过程中所产生电荷和能量能够沿共轭分子链进行有效传递,成倍放大这种作用,从而有效提高了检测灵敏度,这比相应的小分子化合物更具有优越性。目前共轭聚合物已被用于开发新型化学、生物传感器,尤其是在生物分子检测方面的应用得到迅速的发展。本文总结了近年来荧光共轭聚合物在生物传感方面的研究进展,主要讨论共轭聚合物在蛋白质、核酸及毒素检测中的应用。     

NEWS

近年来,水溶性共轭聚合物(WSCPs)以其独特的光电性质,在核酸、蛋白质和离子检测方面的研究备受关注。相对于单个小分子而言,共轭聚合物具有多个吸收单元,因此具有很强的吸光能力,在参与能量转移的过程中,可大幅放大响应信号,提高检测灵敏度。荧光共振能量转移(FRET)作为常用的技术手段,在生物大分子相互作用分析、细胞生理     

基于水溶性共轭聚合物及FRET检测腺苷脱氨酶

近年来,水溶性共轭聚合物( WSCPs)以其独特的光电性质,在核酸、蛋白质和离子检测方面的研究备受关注。相对于单个小分子而言,共轭聚合物具有多个吸收单元,因此具有很强的吸光能力,在参与能量转移的过程中,可大幅放大响应信号,提高检测灵敏度。荧光共振能量转移( FRET)作为常用的技术手段,在生物大分子相互作用分析、细胞生理研究、免疫分析等方面有着广泛应用。     

高灵敏共轭聚合物化学传感器

金属离子和化学小分子的检测在人类健康、环境污染以及食品安全等领域具有重要意义,科学工作者们已经在设计、发展高灵敏化学传感器方面进行了大量研究。在过去的几十年里,共轭聚合物由于其卓越的光电性质,引起了人们极大的关注,并取得了众多革命性科技进展。最近,利用共轭聚合物的荧光信号放大机制,人们设计、发展了一系列新型的化学和生物传感体系。共轭聚合物的信号传感机制包括电子转移,荧光共振能量转移以及共轭聚合物聚集或构象改变。本文主要介绍我们实验室在利用共轭聚合物实现金属离子和化学小分子荧光检测方面取得的进展,并对未来发展方向与面临的挑战进行了讨论。     

共轭聚合物在传感器上的应用

由于其特殊的光学和电子性质,共轭聚合物受到人们的广泛关注.共轭聚合物可以在各种传感器件中用作活性材料,例如:生物传感器;气体、湿度传感器;离子传感器;压力、温度传感器等.本文综述了共轭聚合物在传感器应用方面的一些新的进展.     

基于共轭聚合物的传感器荧光发射红移的策略:pH响应和酶活性检测中的应用

近年来,共轭聚合物(CPs)由于具有独特的光电特性而备受关注。CPs由大量重复的共轭单元组成,相对于小分子,它具有长程π电子共轭、强吸光能力、能带可调以及结构修饰多样性等特点。共轭聚合物受激发后,其能量可沿着分子主链快速迁移到一个受体分子,使受体分子的荧光信号成倍的增加,从而可以提高检测的灵敏度。国内外多个研究组利用CPs的传感信号放大效应设计了一系列高选择性和高灵敏性的生物传感器和化学传感器,用来检测DNA,RNA,     

共轭聚合物的功能化及在生物/化学分析领域的应用

共轭聚合物具有电子高度离域的共轭结构及优异的光吸收和发射特性,在有机电子、化学/生物传感、医学诊断及生物成像等领域具有广泛的应用。特定基团功能化的共轭聚合物含有可特异性识别生物/化学分子的功能基团(如糖基、生物素、羧基、氨基酸、肽段、核酸、抗体、氨基、巯基等),进一步拓宽了共轭聚合物在生物/化学分析领域的应用。本文从功能化基团的不同类别出发,对近年来共轭聚合物的功能化方法及其在生物/化学分析领域的应用(如蛋白质、病原体、Hg2+、Pb2+检测)进行了综述,并对该领域的发展前景进行了展望。     

共轭聚合物荧光传感器的研究进展

共轭聚合物具有共轭分子导线结构,局部微扰在整个聚合物分子链甚至整个聚合物体系内即能得到放大利用,这一性质决定了其具有检测超低含量待测物的能力,且表现出强于小分子荧光传感器的灵敏度.本文概述了荧光共轭聚合物的传感机理,并举例介绍了近年报道的以共轭聚合物为基础的荧光传感器在检测离子及有机小分子方面的应用.     

共轭聚合物为基础的荧光传感器

近年来,借助共轭聚合物的荧光发射与淬灭过程开发化学与生物传感技术成为倍受关注并获得迅速发展的研究领域。由于共轭聚合物能够沿分子链进行能量和电荷传导,从而产生信号放大现象,这类传感器通常都具有较高的灵敏度。本文主要通过对几种具有代表性的此类化学/生物传感器的举例说明,概述荧光共轭聚合物的传感机理,并简要介绍这一领域的发展状况。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).