基于双层类脂膜的去甲肾上腺素传感器

报道了去甲肾上腺素 (NE)在月桂酸 -双层类脂膜修饰的玻碳电极上的电化学行为 ,在 +0.6～ -0.2V(vs.Ag/AgCl)电位范围内 ,于pH7.0的0.01mol/L的KH2PO4-Na2HPO4 底液中 ,去甲肾上腺素产生很灵敏的氧化峰电流。氧化峰电流与去甲肾上腺素浓度在1.7×10 -5～5.9×10 -4mol/L范围内呈良好线性关系。该电极可作为检测去甲肾上腺素的新型高灵敏度电化学生物传感器     

双层类脂膜修饰玻碳电极研究去甲肾上腺素电化学行为及其分析应用

报道了去甲肾上腺素在双层类脂膜修饰玻碳电极上的电化学行为。在 0 .8～ - 0 .3V(vs.Ag/AgCl)电位范围内 ,于 pH 6 .5、0 .0 1mol/LKH2 PO4 Na2 HPO4底液中 ,去甲肾上腺素产生很灵敏的氧化峰电流。该电流与去甲肾上腺素浓度在 3.5× 10 -6～ 3.1× 10 -4mol/L范围内呈良好线性关系。该电极可作为检测去甲肾上腺素的新型的高灵敏度电化学生物传感器。     

血红蛋白在磷脂-月桂酸修饰的玻碳电极上的电化学行为及其分析应用

报道了血红蛋白（Hb）在磷脂-月桂酸修饰的玻碳电极上的电化学行为,在+0. 8～-0.7V (vs. Ag/AgCl)电位范围内,于pH6.0的0.01mol/L的KH_2PO_4- Na_2HPO_4底液中,血红蛋白产生不可逆的还原电流峰。还原峰电流与血红蛋白浓 度在1.25 * 10~(-8)～4.31 * 10~(-7) mol/L范围内呈良好线性关系。该电极可作 为检测血红蛋白的新型的高灵敏度电化学生物传感器。     

氯化血红素在纳米氧化锌-碳糊电极上的电化学行为

以H2C2O4·2H2O和Zn(Ac)2·2H2O为前驱体制备纳米ZnO粉体,用透射电子显微镜、X射线衍射光谱表征了其形貌及晶体结构,并将其用于制备纳米ZnO-碳糊电极,采用循环伏安法和微分脉冲伏安法研究了氯化血红素在电极上的电化学行为。与商品ZnO颗粒-碳糊电极和裸碳糊电极相比,氯化血红素在纳米ZnO-碳糊电极上的还原峰峰电位正移,还原峰峰电流明显增加,表现出明显电催化性能。实验表明,在pH=9.18磷酸盐缓冲液中,-0.30V富集30s后,氯化血红素在-0.440V处有1个灵敏的还原峰,可用于氯化血红素的电化学分析。在优化条件下,该还原峰峰电流与氯化血红素浓度在3.1×10-9～3.1×10-7mol/L内有线性关系,检出限为1.53×10-9mol/L(S/N=3)。将该修饰电极用于红桃K生血剂中氯化血红素测定,结果满意。     

壳聚糖/Nafion膜固定氯化血红素制备过氧化氢生物传感器

以壳聚糖/Nafion复合膜为载体在玻碳电极上固定氯化血红素制备过氧化氢生物传感器。研究了血红素电极制备过程中的影响因素及其电化学性质,在1.0 mol/L pH 9.8的NH3-NH4Cl缓冲溶液中,血红素电极对H2O2的催化还原峰电流与H2O2浓度在7.5×10-5~1.45×10-3mol/L范围内成良好的线性关系,检测灵敏度为35.28μA/mM,检测限为3.5×10-5mol/L(S/N=3),同时研究了血红素电极的重现性、稳定性和选择性。     

氯化血红素在纳米氧化锌碳糊修饰电极上的电化学行为

以H2C2O4·2H2O和Zn(Ac)2·2H2O为前驱体制备纳米ZnO粉体,用透射电子显微镜、X射线衍射光谱表征了其形貌及晶体结构,并将其用于制备纳米ZnO-碳糊电极,采用循环伏安法和微分脉冲伏安法研究了氯化血红素在电极上的电化学行为。 与商品ZnO颗粒-碳糊电极和裸碳糊电极相比,氯化血红素在纳米ZnO-碳糊电极上的还原峰峰电位正移,还原峰峰电流明显增加,表现出明显电催化性能。 实验表明,在pH=9.18磷酸盐缓冲液中,-0.30 V富集30 s后,氯化血红素在-0.440 V处有1个灵敏的还原峰,可用于氯化血红素的电化学分析。 在优化条件下,该还原峰峰电流与氯化血红素浓度在3.1×10-9~3.1×10-7 mol/L内有线性关系,检出限为1.53×10-9 mol/L(S/N=3)。 将该修饰电极用于红桃K生血剂中氯化血红素测定,结果满意。     

肌红蛋白在磷脂-月桂酸修饰的玻碳电极上的电化学行为及其分析应用

报道了肌红蛋白(Mb)在磷脂、月桂酸修饰的玻碳电极上的电化学行为 ,在 +0.2～ -0.7V(vs.Ag/AgCl)电位范围内 ,于pH6.0的0.01mol·L-1的KH2PO4、Na2HPO4底液中 ,肌红蛋白产生不可逆的还原电流峰 ;还原峰电流与肌红蛋白浓度在2.25×10-8 ～1.40×10-6 mol·L-1 范围内呈良好线性关系 ;线性回归方程为Ip(μA)=-0.01419 +0.2382cMb(10 -7mol·L -1) ,线性回归系数r(10)为0.998 ,检出限为1.20×10 -8mol·L -1,该电极可作为检测肌红蛋白的新型的高灵敏度电化学生物传感器。     

阿霉素在氧化铟锡电极上的电化学行为及其应用

阿霉素(ADM)在0.02 mol/L pH 7.50的NaH2PO4-Na2HPO4缓冲溶液中,用氧化铟锡(ITO)电极进行线性扫描伏安法测定,得到一良好的还原峰,其峰电位为-0.63 V。峰电流与ADM浓度在1.0×10-7~5.0×10-6mol/L范围内呈线性关系,检出限为5.0×10-8mol/L。用循环伏安法研究了体系的电化学行为及电极反应机理。实验表明,该体系属两电子还原的不可逆过程。     

一种基于乙炔黑/壳聚糖膜修饰电极的对氨基酚传感研究

制备了一种乙炔黑/壳聚糖薄膜修饰的玻碳电极,用循环伏安法详细研究了对氨基酚在该修饰电极上的电化学行为.结果表明: 对氨基酚在此膜修饰电极上呈现出一对可逆的氧化还原峰.相对于裸玻碳电极,该氧化还原峰的峰电流明显提高,峰电位差减小,可逆性变好,表明乙炔黑/壳聚糖薄膜电极对对氨基酚的电化学氧化具有良好的催化作用.对氨基酚的氧化峰电流与其浓度在1.0×10-7～2.0×10-6 mol/L和2 0×10-6～5.0×10-4 mol/L范围内均呈良好的线性关系; 检出限为5.0×10-8 mol/L(S/N=3).应用此修饰电极测定实际水样,结果较满意.     

聚叶酸修饰电极的制备及其对肾上腺素的电催化氧化研究

采用电化学聚合的方法,将叶酸(FA)聚合在碳糊电极(CPE)表面,制备了聚叶酸修饰碳糊电极(PFA/CPE),并研究了肾上腺素(EP)在该修饰电极上的电化学行为。实验结果显示:在pH 7.0的磷酸盐缓冲溶液中,该聚合膜对EP的氧化有显著的催化作用,EP在修饰电极上产生2个氧化峰和一个还原峰,峰电位分别为0.193V、0.4184V和-0.252V。在测定实验条件下,EP在PFA/CPE上的氧化峰电流与其浓度在2.50×10-7～1.78×10-4mol/L范围内具有良好的线性关系,检出限可达1×10-7mol/L。将该电极应用于EP实际样品的测定,效果良好。     

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.