基于多壁碳纳米管-硫堇/Nafion纳米复合物修饰的人IgG免疫传感器的研究

制备了基于多壁碳纳米管-硫堇/Nafion纳米复合物的人IgG免疫传感器.阻抗谱、循环伏安研究表明,该免疫传感器对人IgG的检测具有优异的性能,其对人免疫球蛋白G(IgG)浓度的定量测定线性范围为1.0 ～ 200μg/L,检出限为0.25 μg/L,线性相关系数R=0.9950.该免疫传感器可用于对人血清中IgG的检...     

插拔式压电肿瘤标志物微阵列免疫传感器的研制

以AT切型、基频10 MHz的金膜石英晶体作为换能器,通过螺旋检测池固定夹具构建一种新型插拔式压电石英晶体传感器,并组装成2×5型压电肿瘤标志物微阵列免疫传感器。研究了传感器的响应特性及参数。该微阵列传感器在甲胎蛋白(AFP)、癌胚抗原(CEA)、前列腺特异性抗原(PSA)和人绒毛膜促性腺激素(hCG)质量浓度分别为20~640μg/L、1.56~50μg/L、1.25~50μg/L、2.5~250 mIU/mL的范围内,压电石英晶体振荡频率偏移值对肿瘤标志物浓度均呈现良好的响应特性。应用微阵列传感器测定68例临床血清标本,结果与化学发光免疫分析法符合(相关系数分别为0.92、0.90、0.91、0.94)。该压电肿瘤标志物传感器微阵列具有结构简单、操作方便、稳定性好、灵敏度和特异性高,不需标记,能实时检测和重复使用等优点,可用于临床实验诊断,具有临床推广应用价值。     

基于聚硫堇和纳米银固定酶的葡萄糖生物传感器

用循环伏安法将电子媒介体硫堇电聚合在玻碳电极表面上,使其表面形成均匀的带负电的聚硫堇膜,通过静电吸附作用吸附表面带正电荷的纳米银溶胶,接着通过静电吸附带负电的葡萄糖氧化酶,最后用聚硫堇包埋电极,从而制得性能优良的葡萄糖氧化酶(GOD)生物传感器。实验发现传感器氧化峰电流与葡萄糖的浓度在1.0×10-8~5.0×10-6mol/L(r=0.9963)范围内呈良好线性关系,检出限为5.0×10-9mol/L(S/N=3)。     

纳米金与磁性纳米复合物构建电流型免疫传感器的研究

制备了易于磁性分离、硫堇(Thi)包覆的四氧化三铁(Fe3O4)纳米复合物。通过静电吸附作用,将萘酚(Nafion)、Thi包覆的Fe3O4复合纳米粒子层层修饰到玻碳电极表面,再利用Thi分子中的氨基吸附纳米金,最后固载甲胎蛋白抗体,从而制得灵敏度高、稳定性好的无试剂电流型甲胎蛋白免疫传感器。实验通过透射电子显微镜(TEM)对该复合纳米粒子进行表征,并用循环伏安法考察了电极的电化学特性。结果表明,Fe3O4/Thi复合纳米粒子修饰的电极在实验过程中呈现出良好的氧化还原活性,其检测范围为0.05～20μg/L,检出限为0.03μg/L。     

基于3,5-二溴水杨醛席夫碱镍配合物-氧化石墨烯电化学免疫传感器检测Anti-IgG含量的研究

应用物理吸附法将羊抗人IgG抗原直接固定于3,5-二溴水杨醛席夫碱镍配合物-氧化石墨烯修饰的金电极表面,制备电化学免疫传感器。采用循环伏安法和交流阻抗法对传感器进行表征,结果表明该传感器适合检测Anti-IgG浓度。同时探讨了缓冲液pH值、扫描速度、免疫反应温度、抗原与抗体配比对循环伏安峰电流的影响,结果表明在5~100mV/s扫速范围内,峰电流与扫速呈线性。孵育最优条件为25℃,h-IgG与Anti-IgG配比为1∶1。循环伏安法研究还表明Anti-IgG浓度在0.01~260μg/L范围内,线性关系良好,相关系数r2=0.993,检出限(S/N=3)为0.006μg/L,据此建立了检测Anti-IgG浓度的新方法。     

免标记电化学免疫传感器用于微囊藻毒素-LR的灵敏检测

采用纳米金作为抗体的固定基质,同时以硫堇为电活性指示剂,构建了一种免标记的电化学免疫传感器用于微囊藻毒素-LR(MC-LR)的灵敏检测。将萘酚修饰到金电极表面,通过静电作用将硫堇捕获。加入纳米金与硫堇的氨基结合,抗体将通过与纳米金作用而固定到电极表面。通过MC-LR与其相应抗体的特异性结合作用阻碍硫堇的电子传递,实现MC-LR的电化学检测。在最优实验条件下,MC-LR的质量浓度与电信号在5~100μg/L范围内呈良好的线性关系,检出限为0.71μg/L,可满足饮用水检测需求,能够用于实际水样中M C-LR的测定。     

快速检测阿尔茨海默标志蛋白(Tau)的阻抗生物传感器研究

通过构建自组装阻抗免疫传感器,对微量Tau蛋白进行检测,以达到辅助早期诊断阿尔茨海默病的目的。传感器通过以下步骤构建,将双功能分子3,3'-二硫代双(磺酸琥珀酰亚氨基丙酸酯,DTSSP)通过Au-S键修饰到金电极表面,通过烷磺基-氨基结合抗体39E10。利用免疫原理,通过抗原-抗体之间的吸附作用特异性结合捕获Tau蛋白,使用交流阻抗法进行表征,并通过循环伏安法验证。通过对DTSSP修饰时间及抗体浓度的优化,传感器对质量浓度为0.02~100μg/m L的Tau蛋白有检测信号,其中在0.2~20μg/m L质量浓度范围内具有良好线性关系,r~2为0.988 8,检出限为0.43 nmol/L,检测时间为15 min。自组装免疫传感器对Tau实现了特异性捕获,可作为AD临床检测的辅助手段。     

基于聚硫堇、DNA/纳米银复合物共修饰癌胚抗原免疫传感器的研究

将硫堇聚合到玻碳电极(GCE)表面形成带正电的多孔聚硫堇(PTH)复合膜, 通过静电吸附固定DNA/纳米银复合物, 利用复合物中纳米银大的比表面积和强的吸附能力将癌胚抗体(anti-CEA)固定到电极表面, 从而制得高灵敏的电流型癌胚抗原(CEA)免疫传感器. 通过循环伏安法考察了电极表面的电化学行为, 并对免疫传感器的性能进行了详细研究. 在最优的实验条件下, 用示差脉冲伏安法(DPV)对癌胚抗原进行检测, 其线性范围为1.0～10.0 ng•mL^－1和10.0～80.0 ng•mL^－1, 线性相关系数分别为0.9983和0.9970, 检测限为0.24 ng•mL^－1, 并将该免疫传感器用于血清样品中CEA的检测.     

用于检测癌胚抗原CEA的丝网印刷免疫传感器

采用溶胶-凝胶技术将电子媒介体亚甲基蓝和辣根过氧化物酶(HRP)标记的癌胚抗原(CEA)固定在一次性丝网印刷碳电极表面,制备了CEA免疫传感器。该免疫传感器在含CEA样品的溶液中培育后,抗原-抗体免疫结合物的形成会阻碍HRP活性中心与亚甲基蓝之间的电子传递,使HRP对H2O2电催化氧化的效率降低。循环伏安和计时电流法用于研究免疫电极的电化学特性,在优化的条件下催化效率的降低与CEA质量浓度分别在1.0~6.0μg/L和6.0~138μg/L范围内成线性关系,检出限为0.4μg/L,测定的组内和组间相对标准偏差分别为7.4%和11.2%。该测定无须分离、洗涤步骤,分析时间短,操作方便,检测成本低,具有实际应用价值。     

石墨烯-壳聚糖复合物修饰电极构建电化学免疫传感器对1-芘丁酸的检测研究

采用石墨烯(GS)和壳聚糖(CS)复合膜修饰玻碳电极(GS-CS/GCE),利用1-乙基-(3-二甲基氨基丙基)碳二亚胺盐酸盐(EDC)和N-羟基丁二酰亚胺(NHS)(4∶1)活化GS-CS/GCE,共价固定多环芳烃抗体(anti-PAHs),构建灵敏度高、稳定性好的非标记电流型免疫传感器,用于1-芘丁酸(PBA)的检测。运用扫描电子显微镜对GS-CS复合膜的形貌进行表征。在pH 7.0含10 mmol/L K3Fe(CN)6和0.1 mmol/L KCl的磷酸盐溶液中,通过循环伏安法和示差脉冲伏安法研究修饰电极表面的电化学性质,并考察了免疫传感器的电化学性能。研究表明,由于石墨烯和壳聚糖的协同作用,GS-CS修饰的玻碳电极在Fe(CN)64-/3-溶液中的峰电流明显增大,有利于提高免疫传感器的灵敏度。在优化实验条件下,电极表面的anti-PAHs抗体固定量显著提高,增强了电极的分子识别性能。由于anti-PAHs抗体-抗原结合物的导电性较差,免疫传感器的峰电流随着待测溶液中PBA浓度的增大而减小,PBA浓度在0.1～80μg/L范围内呈良好的线性关系,检出限为0.03μg/L。该免疫传感器重现性好、特异性强,用于实际样品的测定,回收率为90%～105%。     

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%.     

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.     

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.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

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.     

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.