水溶性共轭聚合物在生物传感中的应用

水溶性共轭聚合物在化学、医学、生命科学以及材料科学等领域中备受研究者们的关注,利用其独特的光化学和光物理性质,研究者们开展了一系列创新性研究并取得了重大的研究进展,进而拓展了聚合物的应用范围.共轭聚合物是一种由多个重复发光单元通过彼此间共轭而形成的高分子化合物,通过对其结构的精准调控,可以获得具有不同性能的功能性分子.其中,通过改变其主链结构,可以获得具有不同吸收和发射波长的荧光探针;通过对侧链结构修饰以水溶性基团和/或选择性识别分子,可以实现与特定靶标间的静电作用或者特异性结合,进而实现选择性识别的目的.本文综述了近年来水溶性共轭聚合物在生物传感中的应用,主要介绍了水溶性共轭聚合物在DNA检测、蛋白质检测、细胞和细菌的检测与区分以及细胞成像等方面的研究进展.     

基于荧光共轭聚合物的金属离子检测

以聚乙炔、聚芴、聚噻吩、聚苯撑为代表的荧光共轭聚合物,由于具有独特的光学性能、自组装性能和结构与性能的可调控性,可作为优异的光学传感材料。利用其具有较高摩尔消光系数和荧光量子产率的特点,可设计具有较高灵敏度和选择性的传感器,这已成为生物传感领域的研究热点。以荧光共轭聚合物为基础的金属离子检测,最初是以非水溶性的共轭聚合物为主,通过金属离子与聚合物链上特定基团(如吡啶、冠醚)的结合引起的聚合物荧光性质的变化可实现对某些离子的检测。在共轭聚合物主链上引入亲水性侧链,可大大增强共轭聚合物的水溶性,为金属离子的生物传感检测提供了新的思路,例如可引入能与金属离子结合的生物分子(如DNA、糖基等)来设计传感策略,进一步提高检测的特异性和灵敏度。本文综述了近年来以非水溶性和水溶性荧光共轭聚合物为传感材料,对具有重要生物学意义的重金属离子(Hg²⁺、Pb²⁺)、过渡金属离子(Cu²⁺、Eu³⁺、Ni²⁺、Fe³⁺、Fe²⁺、Ru³⁺、Ag⁺)和碱金属离子(K⁺、Na⁺、Li⁺)进行高灵敏度检测方面的研究进展,并对该领域的发展前景进行了展望。     

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。     

水溶性共轭聚合物分子刷的研究进展

水溶性共轭聚合物研究属于国际前沿研究领域,因其具有水溶性和超级信号放大作用,在生物传感领域展现出良好的应用前景.但由于传统水溶性线型共轭高分子两亲性结构特点,其含有的憎水性刚性共轭链在水溶液中易聚集,水分子对共轭链激发态的影响导致其发光效率低(一般小于30%),严重制约了其应用与拓展.如何方便有效构筑高分子的高支化是获得高荧光效率的关键.在本篇综述中,我们综述了水溶性共轭聚合物分子刷的合成技术,分析了其结构与光学性质的关系,为水溶性共轭聚合物分子刷的设计和制备提供指导.另外,总结了水溶性共轭聚合物分子刷在化学生物传感、生物成像、药物运输、癌症治疗等领域的应用,最后对水溶性共轭聚合物分子刷存在的主要问题以及未来的热点方向进行了分析和展望!     

共轭聚合物生物电子体系研究进展

共轭聚合物类的有机共轭分子由于其特殊的电子离域效应,具有优异的光电性能.另外该类材料骨架结构丰富、能带可调、易于修饰与制备,使得这类材料除了在发光二极管、场效应晶体管和光伏电池等方面有广泛的研究和应用之外,在生物成像、生物传感、疾病诊断和治疗中也发挥了重要作用.本文综述了近年来基于水溶性共轭聚合物的生物电子体系构建和应...     

生物素功能化水溶性共轭聚合物的合成、表征及其生物分析应用

以四（三苯基膦）钯/碘化亚铜为催化剂,利用Sonogashira偶联反应,合成了一种主链含芴炔苯结构的侧链生物素（biotin）修饰的具有蓝光发射特性的水溶性共轭聚合物（PFPNBr-biotin）. 其结构通过核磁共振和红外光谱进行表征;分子量（分布）利用凝胶渗透色谱进行表征. 研究了该聚合物在不同溶剂、不同浓度及不同pH环境中的光物理性质变化. 与未功能化的共轭聚合物相比,这种生物素功能化的聚合物对亲和素蛋白显示出较高的选择性. 目前,生物素-亲和素系统已在生物分析领域广泛使用,因此,该聚合物在生物分子的特异性检测、荧光标记、细胞及分子成像等领域具有较好的应用前景.     

基于能量转移机理的水溶性荧光共轭聚合物体系的设计制备及应用

水溶性共轭聚合物由于具有优异的光学性能,如强大的光捕获能力和独特的分子线效应,在化学、生物和医疗领域都有良好的应用前景。共轭聚合物受光激发后,所产生的激子可以沿着长程共轭的π骨架自由迁移,在分子骨架的任何位点都可以转移给能量受体,从而实现高效的能量传递。因此,水溶性共轭聚合物适合于构建各种能量传递体系,从而实现荧光信号放大、多色发光、活性氧产生效率提高等光学性能的优化。本文简述了基于水溶性共轭聚合物构建能量转移体系的原理和方法,总结了其在生物传感、生物成像、光动力杀菌和光动力抗癌等领域的应用,最后对水溶性共轭聚合物存在的主要问题以及未来的发展方向进行了分析和展望。     

非共价键法改性碳纳米管的研究进展

阐述了非共价键改性在碳纳米管功能化方面的应用进展,详细介绍了表面活性剂修饰、小分子的π-π堆积相互作用、聚合物的缠绕和包覆、生物大分子的包裹和吸附、内嵌填充修饰等改性方式的研究现状,并提出了非共价键法修饰碳纳米管未来改进的方向,探讨了不同修饰物与碳纳米管之间的相互作用机制。其中,含有共轭基团或芳基基团的聚合物,可以通过其共轭或芳基基团与碳纳米管间的π-π相互作用和范德华作用,实现对碳纳米管的非共价物理包覆。经聚合物功能化的碳纳米管在电池、催化剂、生物传感器和电化学装置上有较好的应用前景。此外,生物大分子对碳纳米管的非共价修饰不仅可以改善其在生物体系中的水溶性,而且通过合理设计还可以避免蛋白质、核酸等生物分子的非特异性吸附,从而得到具有特异性的生物分子-碳纳米管复合体系。     

基于聚噻吩荧光化学敏感材料的设计及其应用

<正>水溶性共轭聚合物,由于其存在大量的重复性吸收单元,具有极强的光捕获能力,它与带电荷的生物分子之间强烈的静电相互作用和荧光信号自身的灵敏性,赋予了水溶性共轭聚合物在免标记生物成像及检测方面非常显著的优势.同时由于共轭链的"分子导线效应"使得其作为荧光探针分子的灵敏度相对于小分子大大提高.通过在共轭链骨架     

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。     

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.     

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.     

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.     

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%).     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.