首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 328 毫秒
1.
光导纤维电化学发光葡萄糖传感器的研究   总被引:7,自引:0,他引:7  
以碳糊为固定化载体 ,将葡萄糖氧化酶固定在碳糊电极上 ,制成了光导纤维电化学发光葡萄糖生物传感器。葡萄糖的酶催化反应、鲁米诺的电化学氧化和化学发光反应在电极表面同时发生 ,因此该传感器的信号响应在 1 0 s内达到发光强度峰值。葡萄糖浓度在 1 .0× 1 0 -5~ 2 .0× 1 0 -2 mol/L范围内与发光强度呈线性关系 ,检出限为 6.4× 1 0 -6mol/L,可应用于市售饮料中葡萄糖的测定  相似文献   

2.
李彤  姚子华 《分析化学》2004,32(2):237-240
基于普鲁士蓝修饰玻碳电极结合二氧化硅溶胶 凝胶固定化酶技术构造具有“三明治”式结构的酶电极。考察了酶电极对葡萄糖的电化学响应以及操作条件。结果表明 :所制备的传感器在pH 6 .5 ,电位为- 0 .0 5V条件下对葡萄糖在 0~ 5mmol/L呈线性响应 ,响应时间为 12s ,检出限为 0 .0 2mmol/L ,灵敏度高达1 182 μA/ (mmol·L-1)。传感器的稳定性好 ,4 5d其响应值仍保持 90 %。  相似文献   

3.
测定葡萄糖的简易分光光度法   总被引:6,自引:0,他引:6  
研究发现葡萄糖与磷钼杂多酸反应 ,能生成有色产物 ,它的最大吸收波长是 690 nm,吸光度与葡萄糖的质量浓度呈线性关系 ,检出限为 2× 1 0 -5mol/L。本法已用于测定葡萄糖注射液中的葡萄糖含量。  相似文献   

4.
Porphyrin dyes have received great attention due to their excellent photovoltaic performance in dyesensitized solar cells(DSSCs). In this work, dyes XC1–XC3 were synthesized by introducing various numbers of bis(4-methoxyphenyl)amino and p-hexyloxyphenyl groups to porphyrin meso-positions.The XC1 molecule contains two p-hexyloxyphenyl groups, and its DSSCs showed the power conversion efficiency of 4.81%. For XC2 and XC3, the replacement of p-hexyloxyphenyl with diphenylamino groups can effectively enhance the light harvesting around 500 nm. However, the highest occupied molecular orbitals(HOMOs) were elevated too much, which suppressed the dye regeneration processes, leading to low cell efficiencies of 2.51% and 1.27% for XC2, and XC3, respectively. To further improve the cell performance, an anthracene derivative C1 was used as the cosensitizer for XC1, which increased both the Jscand Vocvalues, with an improved efficiency of 5.75%.  相似文献   

5.
人工培养菌种茯苓菌丝体多糖的分离、组成和分子量   总被引:6,自引:0,他引:6  
由人工培育的茯苓菌种 (5·78号 )在含麸皮的培养液中于 2 5℃培养 1 8天得到茯苓菌丝体 .分别用9g LNaCl水溶液、热水、0 .5mol LNaOH和 88%甲酸从菌丝体中提取 7种多糖依次为 :ab PCM1、ab PCM2 I、ab PCM2 II、ab PCM3 I、ab PCM3 II、ab PCM4 I、ab PCM4 II,并从培养液中提取一种多糖ab PCM0 .红外光谱 (IR)、气相色谱 (GC)和1 3C NMR分析结果表明ab PCM0至ab PCM3 I多糖主要由α (1→ 3 ) D 葡萄糖、α D 甘露糖、β D 半乳糖和乙酰葡萄糖胺组成 ,而且随提取过程进行 ,葡萄糖含量逐渐增加 ,即从杂多糖到α 葡聚糖 .ab PCM3 II、ab PCM4 I和ab PCM4 II则主要是 β (1→ 3 ) D葡聚糖 .有趣的是 ,α 葡聚糖和 β 葡聚糖共存在该菌丝体的碱水提取液中 .由粘度法和光散射法测定了多糖的特性粘数 [η]和重均分子量Mw .ab PCM0、ab PCM1、ab PCM2 I、ab PCM2 II、ab PCM3 I和ab PCM4 II多糖的Mw 值分别为 7 7× 1 0 4、5 2× 1 0 4、5 0× 1 0 4、2 4 3× 1 0 4、65 2×1 0 4和 2 5 5× 1 0 4.  相似文献   

6.
茯苓菌丝体多糖的分离及结构分析   总被引:23,自引:0,他引:23  
由茯苓菌种在培养基中于 2 5℃下培养一周得茯苓菌丝体 .分别用 0 9%NaCl水溶液、热水、0 5mol/LNaOH和 88%甲酸从该茯苓菌丝体中提取出四种多糖 ,编号为PCM1 ,PCM2 ,PCM3和PCM4 .用红外光谱 (IR) ,高效液相色谱 (HPLC) ,气相色谱 (GC)及13 C 核磁共振 ( 13 C NMR)等方法分析了它们的组成和结构 .结果表明 ,PCM1 ,PCM2为酸性杂多糖由D 鼠李糖、D 木糖、D 甘露糖、D 半乳糖、D 葡萄糖及葡萄糖醛酸组成 .PCM3主要为线型 β ( 1→ 3 ) D 葡聚糖 ,其产率占茯苓菌丝体总量的 55 8% .PCM4由D 葡萄糖和葡萄糖醛酸组成 .茯苓菌丝体化学组成和结构基本同于茯苓菌核多糖 ,随提取过程进行葡萄糖含量逐渐增加的变化规律也相同 .  相似文献   

7.
定量测定葡萄糖方法的研究   总被引:2,自引:0,他引:2  
在生物化学和碳水化合物化学的研究和开发工作中 ,往往需要定量地测定葡萄糖含量。半胱氨酸 -硫酸法早在 1 949年由 Dische Z提出 ,经过本试验改进的半胱氨酸法是一种简便、有效的定量测定葡萄糖含量的方法。1 试验部分1 .1 半胱氨酸法1 .1 .1 试剂硫酸溶液 :86% (体积分数 )半胱氨酸试剂 :用半胱氨酸盐酸盐的一水合物与硫酸溶液配制成约 0 .0 3% (质量分数 )的半胱氨酸试剂。1 .1 .2 试验方法将 1 ml(含葡萄糖 0~ 40μg)已知或未知溶液在冷却 (自来水冷却 )条件下 ,与 5ml半胱氨酸试剂均匀混合。混合液在沸水中加热 3min后待其冷却到…  相似文献   

8.
葡萄糖及其衍生物的直接紫外检测毛细管区带电泳研究   总被引:1,自引:0,他引:1  
 发展了在 195nm波长下直接检测葡萄糖及其衍生物的毛细管区带电泳方法。在未涂渍石英毛细管中 ,以 5 0mmol/LNa2 HPO4 5 0mmol/LNaH2 PO4 为缓冲液体系 (接近生理条件 pH 7 4) ,分离了葡萄糖及其衍生物 (葡萄糖胺、N 乙酰葡萄糖胺和葡萄糖酸钠 )。在各自相应的浓度范围内 ,峰面积与样品浓度之间呈现良好的线性关系。方法简单、快速、重复性好 ,为研究葡萄糖及其衍生物与凝集素的相互作用奠定了分离检测的基础。  相似文献   

9.
李峰  李瑛琇  朱果逸 《应用化学》2002,19(7):705-707
β-D-葡萄糖的检测是临床化学的常规分析项目 .化学发光分析法测定葡萄糖具有线性范围宽、灵敏度高等优点[1~ 3] .我们曾研究了鲁米诺 ( L uminol) -KIO4 -H2 O2 化学发光反应体系[4 ] ,发现 H2 O2 浓度在 2 .0× 1 0 - 7~ 6.0× 1 0 - 4mol/L范围内与发光强度有良好的线性关系 .本文将生成 H2 O2 的葡萄糖 -葡萄糖氧化酶 ( GOD)的酶促反应与鲁米诺 -KIO4 -H2 O2 的化学发光反应相偶合 ,结合流动注射技术 ,建立了一种流动注射化学发光测定葡萄糖的新方法 .方法的线性范围为 0 .6~ 1 1 0 mg/L ,相关系数为 0 .9997,检出限为 0 .0…  相似文献   

10.
以碳化钨(WC)和Vulcan XC-72炭黑(XC)为载体制备了XC载Ir(Ir/XC)和WC/XC载Ir(Ir-WC/XC)催化剂,在用X射线能量色散谱、X射线衍射谱对催化剂表征的基础上,用电化学方法研究了2种载体Ir催化剂对氨氧化的电催化性能,发现氨在Ir-WC/XC催化剂电极上的氧化峰峰电流密度比在Ir/XC催化剂电极上大31.26%,而且电催化稳定性明显好于Ir/XC催化剂。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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%).  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
19.
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 CuI 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).  相似文献   

20.
(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.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号