掺杂纳米普鲁士蓝溶胶-凝胶修饰葡萄糖生物传感器

采用溶胶-凝胶法制备了纳米普鲁士蓝微粒,将含纳米普鲁士蓝微粒的TiO2溶胶-凝胶固定在玻碳电极表面得到纳米普鲁士蓝修饰电极,该电极对H2O2产生灵敏的响应,线性范围为0．5～400μmoL／L,较常规普鲁士蓝修饰电极(线性范围为25～500μmol／L)灵敏。电极表面再用溶胶．凝胶法固定葡萄糖氧化酶后构建了葡萄糖生物传感器,响应范围0～20mmoL／L,葡萄糖氧化酶表观米氏常数为8．04mmoL／L。实验表明,该法适合于批量制作高灵敏和高重现性的生物传感器。     

基于溶胶-凝胶固定技术的生物组织传感器

报道了一个制备生物组织传感器的新技术。将溶胶 凝胶与植物液汁按一定比例结合 ,使天然植物中的多酚氧化酶被固定于溶胶 凝胶中 ,将其滴涂于预先涂有一层Nafion膜的铂盘电极表面 ,构成带有Nafion 溶胶凝胶 植物液汁的复合修饰膜的生物传感器 ,用于测定神经递质多巴胺。采用循环伏安法和线性扫描伏安法考察了传感器的电化学特性 ,比较了不同植物品种及其不同部位组织的生物催化活性 ;研究了乙醇用量、水酯比、植物液汁用量等因素的影响 ;考察了Nafion膜的防干扰性能。采用差示脉冲伏安法对多巴胺进行定量分析 ,线性范围为 2× 10 -6～ 1× 10 -4mol/L ;检出限为 8.0× 10 -7mol/L。与传统的组织电极相比 ,本传感器具有一系列特点。     

壳聚糖-磷酸二氢胆碱凝胶固定肌红蛋白的直接电化学和电催化

使用壳聚糖和亲水性离子液体磷酸二氢胆碱形成的复合水凝胶固定肌红蛋白(Mb)制备修饰电极。在修饰电极表面,实现了Mb的直接电化学和对O2、H2O2的电催化。同时,该修饰电极表现出了较高的热稳定性。研究表明该新型复合水凝胶具备较好的生物相容性,使膜内的Mb保持了其天然构象和活性,并且很大程度地提高了修饰电极的导电性,促进了Mb和电极之间的电子传递,在直接电化学、生物催化和第三代生物传感器的制备等领域有良好的应用前景。     

基于新材料Mg/Ni/Fe水滑石的葡萄糖传感器的研究

葡萄糖浓度的测定在生物,医学,环境检测和食品工业等方面有着极其重要的意义,因此近年来已有许多方法被用于制各葡萄糖生物传感器.电化学生物传感器对葡萄糖的测定占据着主导作用,因为它有着灵敏度高,重现性好,操作简单等优点.到目前为止,已有多种材料用于葡萄糖氧化酶的固定,如粘土、无机、有机聚合物、凝胶以及生物材料等.近年来,用阴离子粘土修饰电极特别是水滑石也开始了深入的研究.     

酶促水凝胶的合成及生物传感应用研究进展

近年来,聚合物基水凝胶材料已经成为一种独特的修饰材料,为新型生物传感器的设计提供了新思路.酶具有特异性高、毒性低、催化效率高等良好特性,已被用于催化聚合各种新型水凝胶.本文综述了几种酶促水凝胶的合成方法及其在细胞代谢物、组织工程、伤口愈合和癌症监测等方面的潜在应用,并对基于酶促水凝胶反应的生物传感器的制备与应用进行了总结与展望.     

基于水凝胶的细菌传感检测

水凝胶具有含水量高、柔韧性好、黏弹性高、生物相容性高以及独特的刺激响应特性,这使得水凝胶材料在细菌传感检测方面备受关注。基于水凝胶的细菌传感器及传感芯片的研究,对细菌的基础科学研究具有重要意义,更对细菌的快速高效检测、特定环境中的细菌污染防控和疾病传播控制等具有重要应用价值。本文针对近年来水凝胶在细菌传感检测方面的研究工作进行综述。简要介绍了水凝胶的种类,水凝胶与细菌之间相互作用的影响因素。重点综述了基于温敏型水凝胶、pH敏感型水凝胶、酶敏感型水凝胶以及特异性标识物功能化修饰的水凝胶构建的传感器和传感检测方法,并综述了基于水凝胶的新型柔性传感器和微流控传感芯片的研究进展。基于水凝胶的细菌传感器在检测效率、信号采集和稳定性等方面仍需进一步提升和拓展。随着新型水凝胶材料的出现,智能细菌传感器、柔性细菌传感器和集成微流控细菌传感芯片是目前发展的方向,在细菌检测方面显示出良好的发掘潜力和应用前景。     

基于室温离子液体和有序大孔金膜的酶传感器

将室温离子液体1-丁基-3-甲基咪唑四氟硼酸盐([BMIM]BF4)、N,N-二甲基甲酰胺(DMF)、及不同种类的膜材料与各种酶一起通过混合涂布、逐层修饰的方式固定于三维有序大孔金膜电极表面,构建一种新型的生物酶传感器。血红蛋白(Hb)、肌红蛋白(Mb)和辣根过氧化物酶(HRP)在该修饰电极上呈现出明显的还原峰,这归因于三种酶活性中心的直接电化学行为。分别构建四种不同膜材料的修饰电极,研究了硅凝胶、壳聚糖、Nafion膜和琼脂糖水凝胶四种材料对于L-乳酸脱氢酶(LDH)修饰电极催化响应的影响,结果表明选择壳聚糖作为膜材料是最优选择。将壳聚糖修饰的LDH金膜电极用做检测乳酸浓度的生物传感器,该传感器表现出良好的催化性能,线性响应范围为10~250nmol/L,检测限(S/N=3)为3.3nmol/L。     

辣根过氧化物酶生物传感器检测苯肼的研究

采用酸性溶胶法在碳纳米管(CNT)上负载纳米TiO2颗粒,制备了CNT-TiO2修饰电极,利用TiO2与辣根过氧化物酶(HRP)间的静电吸附及TiO2与羧基的高反应特性,实现了HRP在CNT-TiO2修饰电极表面的固定.实验发现,该生物传感器对邻氨基苯酚过氧化氢溶液的氧化还原有很好的催化作用,利用苯肼对HRP的抑制作用实现了对环境污染物苯肼的检测.该生物传感器寿命长,性能稳定且可以重复使用.     

纳米水凝胶合成方法的研究进展

粒径在1～1000nm范围内的纳米水凝胶可用于药物输送、医学诊断、生物传感器和生物物质分离等领域,近年来受到国内外普遍关注。本文从合成纳米水凝胶的原料入手,分别从单体与交联剂聚合和聚合物后交联两个方面综述了纳米水凝胶合成方法的研究进展。通过单体与交联剂聚合合成纳米水凝胶的方法主要有三种:沉淀聚合法、反相乳液聚合法和微模板聚合法。采用聚合物后交联合成纳米水凝胶的方法主要有四种:沉淀/交联法、乳化/交联法、自组装/交联法和微模板成型/交联法。另外,对这些合成方法的优缺点进行了评述,并对生物医用纳米水凝胶合成方法的研究方向提出了一些粗浅的看法。     

自组装超分子膜修饰电极的研制及分析应用

阐述了自组装超分子膜修饰电极的发展概况及超分子体系形成的理论基础，并对自组装超分子膜修饰电极的特点、电化学行为、功能膜的制备和表征方法以及它在电催化、生物传感器、离子选择性电极等方面的应用进行了综述。     

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%.     

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.     

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.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.     

Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water

A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.     

Construction of polyheterocyclic spirotetrahydrothiophene derivatives via sulfa-Michael/aldol cascade reaction

A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).     

Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: a non-product specific route to C-8 substituted analogues

Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO₄ oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.