CdTe量子点-Ru(bpy)_3~(2+)体系阴极电致化学发光法测定邻苯二酚

根据邻苯二酚对Cd Te量子点增敏的Ru(bpy)32+阴极电致化学发光强度有较强的抑制作用,建立了一种简单的测定邻苯二酚的电致化学发光分析方法。分别探究了磷酸盐缓冲溶液的浓度、pH、量子点的浓度、Ru(bpy)_3~(2+)的浓度、扫描速率以及电位等因素对该体系发光行为的影响。在优化实验条件下,电致化学发光强度的对数与邻苯二酚浓度的对数在7.0×10~(-8)~4.0×10~(-5)mol/L范围内呈现良好的线性关系,检出限为2.3×10~(-8)mol/L(3σ)。对4.0×10~(-6)mol/L的邻苯二酚标准溶液进行六次平行测定,其电致化学发光强度的相对标准偏差(RSD)为1.1%。该方法可成功应用于模拟环境水样中邻苯二酚的含量测定,加标回收率介于95.0%~105.7%之间。     

磁性粒子表面自组装辛可宁分子印迹电致化学发光传感器

以辛可宁为模板分子、十二烷基硫醇为功能单体,在Fe3 O4@Au纳米粒子表面自组装辛可宁分子印迹膜,构建了新型磁性粒子-分子印迹电化学发光传感器。通过透射电子显微镜对磁性纳米粒子的粒径分布及形貌进行了表征,使用红外光谱对比分析了辛可宁、分子印迹膜洗脱前和洗脱后的结构及成分。结果表明,在最优的实验条件下(0.012 mol/L 硼砂缓冲溶液(pH 9.5),0.8 mmol/L Ru(bpy)2+3),辛可宁浓度的对数在1×10-10~9×10-8 mol/L范围内,与电化学发光强度变化值有良好的线性关系,检出限为3.5×10-11 mol/L。此传感器灵敏度高、选择性好、易于更新,将其用于血清样品的检测,方法回收率为98.8%~104.7%。     

构建新型固相电致化学发光传感界面用于检测三丙胺

通过静电作用将带正电的Ru(bpy)23+和带负电的纳米铂制备成铂钌纳米复合物(Ru-PtNPs),并将其滴涂在Nafion分散的多壁碳纳米管(MWCNTs-Nafion)复合膜修饰的玻碳电极上,制备了一种新的基于联吡啶钌的固相电致化学发光(ECL)传感器。利用扫描电镜以及电致化学发光的方法对传感界面进行表征。实验结果表明,通过此种方式可将大量的发光试剂Ru(bpy)23+固载到电极表面,并对三丙胺(TPA)保持良好的电催化活性,Ru-PtNPs/MWCNTs-Nafion修饰电极在0.1 mol.L-1磷酸盐缓冲溶液(PBS,pH 7.4)中对TPA的响应有很好的灵敏度和稳定性,线性范围为6.67×10-7～1.00×10-3mol·L-1,检出限(S/N=3)为3.3×10-7 mol·L-1。     

硫化镉量子点对三联吡啶钌电化学发光的增敏作用及用于邻苯二酚的检测

研究了CdS量子点(CdS QDs)对三联吡啶钌(Ru(bpy)_3~(2+))电致化学发光(ECL)信号的作用,发现CdS QDs对Ru(bpy)_3~(2+)的ECL信号有良好的增敏作用,基于此建立了高灵敏的CdS QDs/Ru(bpy)_3~(2+)ECL体系。探讨了该体系的ECL机理,考察了CdS QDs的浓度、缓冲溶液p H值、扫描速率等实验参数对ECL信号的影响,优化了体系的ECL条件。基于邻苯二酚对该体系ECL信号的抑制作用,建立了邻苯二酚的ECL检测方法。在1.0×10~(-8)~1.0×10~(-5)mol/L范围内,邻苯二酚的浓度与ECL信号的变化值呈良好的线性关系,检出限(S/N=3)为5.5 nmol/L,将本方法用于茶叶中邻苯二酚的检测,结果令人满意。     

基于Ru(bpy)■-三乙胺体系的电致化学发光生物传感器检测葡萄糖

联吡啶钌(Ru(bpy)■)拥有优良的电致化学发光(ECL)性能,但其较好的水溶性使其固载面临巨大问题。该文制备了Pt纳米粒子与Ru(bpy)■的复合物(Pt NPs-Ru),将其修饰于电极并进一步固载葡萄糖氧化酶(GOx)制得传感器。基于H2O2对Ru(bpy)■-三乙胺体系ECL信号的猝灭作用,随着葡萄糖浓度的增加,其在GOx的催化下原位产生的H2O2量增多,导致ECL信号逐渐减弱,从而实现葡萄糖的检测。ECL强度与葡萄糖浓度的对数在1.0×10-8~5.0×10-5 mol/L范围内呈良好的线性关系,检出限低至5.2×10-9 mol/L。传感器具有好的稳定性和高的选择性。Pt NPs-Ru复合物为ECL传感器的构建提供了良好平台,为葡萄糖检测提供了新方法。     

联吡啶钌体系电化学发光法测定舒必利的研究

采用了循环伏安(CV)和电致化学发光(ECL)法,研究了舒必利增强联吡啶钌[Ru(bpy)23+]体系的电化学行为和电化学发光行为,建立了以玻碳电极为工作电极的舒必利电致化学发光分析方法。研究结果表明,在0.1mol/L的磷酸盐缓冲溶液(pH=7.5)中,扫描速度为100mV/s时,ECL的峰高与舒必利浓度在4.0×10-7～1.0×10-4mol/L范围内呈线性关系,相关系数r=0.9957,检出限(S/N=3)为5.3×10-8mol/L。连续平行测定2.0×10-5mol/L的舒必利溶液10次,发光强度值的相对标准偏差(RSD)为1.56%。对样品进行回收率试验,回收率在95.0%～105.0%之间,RSD为4.43%(n=5)。该方法具有较高的选择性和灵敏度,样品处理简单快速,用于药物中舒必利的测定,结果满意。     

毛细管电泳电致化学发光法测定洛贝林的研究

基于稀土掺杂类普鲁士蓝化学修饰电极对Ru(bpy)32 的电催化氧化可增敏电致发光信号,建立了一种毛细管电泳-电致化学发光测定洛贝林的新方法。研究了工作电极电位、缓冲液的酸度及其浓度、分离电压和进样时间等实验参数对洛贝林测定的影响。在优化的实验条件下,其线性范围为1.5×10-7mol/L~1.5×10-4mol/L,检出限(S/N=3)为5.0×10-8mol/L。本法可直接用于注射液和空白人尿中洛贝林的测定,回收率为98.3%~101.2%。     

氮掺杂石墨烯量子点/Ru(bpy)_3~(2+)体系电致化学发光法检测邻苯二酚

采用简单的方法合成了氮掺杂石墨烯量子点(NG QDs),并分别用荧光光谱仪和透射电子显微镜进行了表征。研究了NG QDs对Ru(bpy)_3~(2+)电致化学发光(ECL)体系的增敏作用。实验优化了体系pH、Ru(bpy)_3~(2+)用量、NG QDs用量以及扫速等条件。在最优条件下,根据邻苯二酚对NG QDs/Ru(bpy)_3~(2+)耦合ECL体系信号的猝灭作用,建立了测定邻苯二酚的新方法。邻苯二酚浓度(1.0×10~(-8)～1.0×10~(-5) mol/L)的对数值与ECL信号强度差之间呈线性关系,检测限低至5.0×10~(-9) mol/L,而且选择性和重现性好,实际样品检测结果令人满意。     

Silica sol/Nano-Au/PVP修饰金电极电致化学发光测定槐定碱

基于槐定碱对联吡啶钌(Ru(bpy)2+3)在电致化学发光中的增敏机理,通过传感器修饰技术,将Silica sol/Nano-Au/PVP修饰到金电极表面,建立了简单、快捷测定槐定碱的新方法。实验表明,最佳实验条件下,在1.6×10-7~1.6×10-4mol/L范围内,槐定碱的浓度与其对应的电化学发光强度值呈良好的线性关系,I=4.000×107c+262.2,r2=0.994 5,检出限(S/N=3)为3.5×10-9mol/L。连续平行测定浓度为1.6×10-5mol/L的槐定碱溶液6次,其相对标准偏差(RSD)为2.9%。该方法具有较高的选择性和灵敏度,样品处理简单快速,用于槐定碱的测定,结果满意。     

基于Ru(bpy)■-三乙胺体系的电致化学发光生物传感器检测葡萄糖

联吡啶钌(Ru(bpy)■)拥有优良的电致化学发光(ECL)性能,但其较好的水溶性使其固载面临巨大问题。该文制备了Pt纳米粒子与Ru(bpy)■的复合物(Pt NPs-Ru),将其修饰于电极并进一步固载葡萄糖氧化酶(GOx)制得传感器。基于H_2O_2对Ru(bpy)■-三乙胺体系ECL信号的猝灭作用,随着葡萄糖浓度的增加,其在GOx的催化下原位产生的H_2O_2量增多,导致ECL信号逐渐减弱,从而实现葡萄糖的检测。ECL强度与葡萄糖浓度的对数在1.0×10~(-8)～5.0×10~(-5) mol/L范围内呈良好的线性关系,检出限低至5.2×10~(-9) mol/L。传感器具有好的稳定性和高的选择性。Pt NPs-Ru复合物为ECL传感器的构建提供了良好平台,为葡萄糖检测提供了新方法。     

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.     

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%).     

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.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.