基于CuO-NiO复合氧化物的无酶葡萄糖传感器

通过化学共沉淀法制备了CuO-NiO复合氧化物。在最优条件下,该复合物修饰玻碳电极对葡萄糖检测的线性范围为2×10-6~4.1×10-3mol/L;灵敏度为4116μA·L·mmol-1·cm-2;检测限为0.2μmol/L(S/N=3)。传感器可用于葡萄糖检测。     

毛细管电泳安培法测定田基黄中的芦丁与槲皮素

建立了毛细管电泳电化学分离检测田基黄中生物活性成分芦丁和槲皮素的方法。考察了检测电极电位、缓冲液浓度、pH、运行电压和进样时间对分离的影响。以40 cm长,50μm内径的石英毛细管作为分离通道,运行缓冲液为25 mmol/L硼砂(pH 9.2)溶液,分离电压12 kV,0.3 mm直径的铂圆盘电极为检测电极,检测电位1.00 V(vs.Ag/AgCl),芦丁和槲皮素在10 min内得到良好分离。在上述实验条件下,芦丁和槲皮素分别在8.2×10-6~5.2×10-4mol/L与6.8×10-6~7.2×10-4mol/L范围内与峰面积呈良好线性关系,检出限分别为9.0×10-7mol/L(S/N=3)和4.7×10-7mol/L(S/N=3)。方法已应用于田基黄药材提取物成分分析。     

基于新型共反应物的流动注射电化学发光分析方法研究

为提高钌联吡啶电化学发光强度,对比研究了低浓度Ru(bpy)23+与N-丁基二乙醇胺、N,N-二丁基乙醇胺和三丙胺三种常用胺类共反应物的电化学发光响应情况,结果表明Ru(bpy)23+/N-丁基二乙醇胺体系的电化学发光特性最佳。实验对该体系在流动注射电化学发光分析系统中的检测条件进行了优化。在电位1.8V,进样量150μL,推速30μL/s的最优检测条件下,获得Ru(bpy)23+的检出限(S/N=3)为5.0×10-10 mol/L。方法线性范围为1.0×10-9～5.0×10-7 mol/L;重复性良好,相对标准偏差(RSD)<5%。     

基于二氧化硅包裹三联吡啶钌的新型咖啡因电致化学发光传感器

将包裹了三(2,2'-联二吡啶)二氯化钌(Ⅱ)配合物(Ru(bpy)32+)的二氧化硅纳米粒子(Ru(bpy)32+@Si O2)通过Nafion膜修饰在玻碳电极上,并研究了咖啡因在此电极上的电化学发光行为。在单因素实验的基础上,结合响应面分析法对实验条件进行了优化,建立了一种检测咖啡因的新方法。在最佳的实验条件下,咖啡因浓度在5.0×10-3~20μmol/L范围内与其相对发光强度呈良好的线性关系(r2=0.9996),检出限(S/N=3)为1.3×10-3μmol/L。连续平行测定1μmol/L的咖啡因溶液5次,相对发光强度的RSD为3.8%。方法用于可乐样品的实际测定,回收率为93.7%~103.8%。     

纳米金修饰的碳纤维超微电极在高浓度抗坏血酸体系中选择性测定多巴胺

将柠檬酸三钠与硼氢化钠还原氯金酸制备纳米金颗粒,采用一步恒电位沉积的方法在碳纤维超微电极上沉积纳米金颗粒,并对电极进行电化学表征。分别对100μmol/L DA、1mmol/L AA在该电极上修饰前后的电化学行为进行了研究,结果表明在浓度为1 mmol/L抗坏血酸共存下,DA的浓度(0. 1～10μmol/L)与氧化峰电流成正比,线性回归方程为Ip(μA)=200 c(μmol/L)+2×10~(-4),相关系数R~2=0. 9979,线性范围0. 1～10μmol/L,检出限为1. 28×10~(-2)μmol/L (S/N=3)。方法可用于较高浓度抗坏血酸共存下对多巴胺的选择性测定。     

毛细管电泳分离检测中草药叶下珠中铜钴锌

以甲基百里酚蓝(MTB)为柱前配位剂,建立了毛细管电泳分离检测Cu、Co、Zn的方法。探讨检测波长、缓冲体系、缓冲液浓度、pH值及配位方式等对分离的影响。最佳实验条件为20 mmol/L Na2HPO4-NaOH 2.5×10-4mol/L MTB 60 mmol/L SDS(pH9.50)。线性范围为5.0×10-6mol/L~1.0×10-4mol/L,Cu、Co、Zn的检出限分别为2.0μmol/L、2.0μmol/L和1.0μmol/L。方法应用于经湿法消化处理的叶下珠样品中Cu、Co、Zn的测定,结果满意。     

μ-氧代-二[N,N'-亚乙基双水杨醛合铁(Ⅲ)]配合物合成表征及生物活性

本文合成了μ-氧代-二[N,N'-亚乙基双水杨醛合铁(Ⅲ)]配合物,通过X-射线单晶衍射进行了配合物的表征。分别用紫外光谱法,凝胶电泳法,涂布平板法、最小抑菌浓度(MIC)法研究其生物活性。结果表明浓度为10-2mol/L时标题配合物自由基清除率达33%,是相同条件下抗坏血酸自由基清除率的1.7倍,在水解条件下将质粒DNA切成线性(Form Ⅲ),在H2O2存在时速率加快。配合物对金黄色葡萄球菌、枯草杆菌、大肠杆菌、荧光假单胞菌均有活性,对四种菌的最小抑菌浓度分别为6.25×10~(-5)mol/L、5×10~(-4)mol/L、6.25×10~(-5)mol/L、5×10~(-4)mol/L。     

壳聚糖-二茂铁复合物的制备及其在电化学传感器上的应用

壳聚糖-二茂铁复合物(CHIT-Fc)由二茂铁羧酸的羧基和脱乙酰壳多糖的羟基缩合合成,并通过红外光谱检测.合成得到的壳聚糖-二茂铁复合物通过物理吸附作为固定胆固醇氧化酶(CHOx)的基体.同时,使用Nafion稀释液可以消除诸如抗坏血酸和尿酸的影响.最佳测试条件下,采用示差脉冲(DPV)研究胆固醇生物传感器的响应,在4.0×10-6mol/L～1.0×10-4 mol/L范围内,氧化峰电流与胆固醇浓度呈现良好的线性关系,线性方程为Ipa=0.0223c-0.0875(Ipa:μA,c:μmol/L,R=0.9982),检测限为5.0×10-7mol/L(S/N=3).     

纳米铜修饰玻碳电极的制备及其对葡萄糖的催化氧化

在表面活性剂十六烷基三甲基溴化铵(CTMAB)的分散作用下,通过恒电位还原CuSO4在玻碳电极上沉积Cu,得到纳米Cu修饰玻碳电极(nano-Cu-GCE),该修饰电极对葡萄糖(Glu)的氧化具有明显的催化作用,利用该催化作用对Glu进行检测,通过研究沉积电位、沉积时间以及检测电位对电流信号的影响,优化了电极的制备条件和Glu的检测条件。沉积电位为-100mV,沉积时间8min。在检测电位400mV下,Glu在1.0×10-6~3.9×10-4mol/L范围内Glu电流与空白溶液电流值之差与其浓度呈线性关系,检出限为2.6×10-7mol/L(S/N=3),线性回归方程Δi(μA)=-1.02-125674.54C(mol/L),r=0.9981。抗坏血酸(AA)、对乙酰氨基酚(AP)和L-半胱氨酸(Cys)对Glu信号几乎无干扰。     

维生素B6在纳米金/石墨烯修饰电极上的电化学行为

将金纳米粒子电沉积在石墨烯修饰的玻碳电极表面,研究了维生素B6(VB6)在该修饰电极上的电化学行为。扫描电镜用于该修饰电极组装过程的形貌表征。实验结果表明:VB6在此修饰电极上出现一个良好的氧化峰,在最佳实验条件下,其氧化峰电流与VB6浓度在5.0×10-8～2.0×10-5 mol/L范围内呈线性关系,其线性回归方程为I(μA)=0.5697c(μmol/L)+0.06275,R=0.9992,检出限为2.0×10-8 mol/L(S/N=3)。一些常见的干扰物质如抗坏血酸不干扰VB6的检测。方法已用于片剂中VB6的含量的检测。     

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.