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环糊精聚合物与苯醌的分子包合作用及其在酶电极中的应用 总被引:1,自引:1,他引:0
研究了水溶性环糊精预聚合物的存在对苯醌/氢醌体系在铂电极上氧化还原行为的影响, 根据伏安曲线讨论了该预聚合物与苯醌的分子包合作用。环糊精预聚合物与戊二醛缩聚反应而形成的不溶性聚合物膜用于葡萄糖氧化酶的固定化, 以制得新型的第二代葡萄糖电极。由于分子包合作用, 作为电子受体的苯醌在含酶的环糊精聚合物膜中具有较高的浓度, 从而加速了固定化酶的电子传递。测定了酶电极上BQ反应的动力学参数。 相似文献
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环糊精包合作用对疏水缔合聚合物流变调节与应用 总被引:1,自引:0,他引:1
近年来,利用超分子作用力调节体系流变行为备受人们关注,已在多领域中展现出广泛的应用前景。而环糊精包合作用是一类重要的超分子作用力,向缔合聚合物水溶液中加入环糊精,将拆散缔合结构,引起粘度和粘弹性急剧下降;竞争客体或酶的加入又会诱导分子间发生新的组装行为,使体系流变性得到恢复。本文综述了基于环糊精包合作用的分子组装与流变调节在理论及应用方面的研究现状,重点介绍了环糊精对不同缔合聚合物溶液的流变影响规律和外加物质对体系流变恢复的调节。 相似文献
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本文综述了近年来基于环糊精包合作用的超分子水凝胶的研究进展,主要包括:环糊精与线性、星型、接枝、超支化聚合物包合形成的多聚(准)轮烷自组装制备超分子物理凝胶及功能化多聚(准)轮烷经交联反应制备超分子化学凝胶;环糊精、环糊精二聚体及其水溶性聚合物与带疏水性侧基的聚合物经“锁-钥匙”包合作用形成超分子物理凝胶;及其在药物、基因释放载体与组织工程支架中的应用。着重介绍了剪切、温度、pH值、光等刺激-响应性超分子水凝胶的设计与制备。 相似文献
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将葡萄糖氧化酶(GOD)固定在α-环糊精聚合物中,而电子传递体分子被包含在环糊精腔穴中。固定化酶膜的FTIR测定表明,GOD与环糊精聚合物发生共价连接。制备了含电子传递体的不同GOD酶电极并比较了它们的性能。含四硫代富瓦烯的酶电极具有良好的电流响应特性,可望成为第二代葡萄糖酶电极的新构型。 相似文献
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环糊精包合作用诱导聚合物自组装的研究进展 总被引:1,自引:0,他引:1
将主客体识别与聚合物自组装相结合,利用环糊精对聚合物的包合作用在溶液中诱导聚合物组装形成结构可控的纳米粒子,形成有别于基于环糊精/聚合物包合作用形成的结晶粉末和超分子水凝胶的新型材料.本文介绍了这种诱导组装方案的研究背景及最新的研究成果,综述了诱导组装的原理、特点及影响因素.研究表明,由这种方案制备的聚合物纳米粒子具有超分子动态可逆的特征,进而显示出对温度和pH等敏感的性质.该类环糊精包合作用诱导组装的聚合物超分子聚集体在生物医学材料方面具有潜在的应用价值,如用作药物和基因的可控传递释放载体. 相似文献
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将葡萄糖氧化酶固定在α-环糊精聚合物中,而电子传递体分子被包含在环糊精腔穴中,固定化酶膜的FTIR测定表明,GOD与环糊精聚合物发生共价连接,制备了含电子传递体的不同GOD酶电极并比较了它们的性能,含四硫代富瓦烯的酶电极具有良好的电流响应特性,可望成为第二代葡萄糖酶电极的新构型。 相似文献
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以β-环糊精聚合物的超分子包结物为固定化介质的安培型过氧化氢传感器的研究 总被引:5,自引:0,他引:5
阐述了一种新的生物传感器的固定化方法.利用β-环糊精聚合物(β-CDP)与亚甲基蓝间的超分子作用及β-CDP与戊二醛间的缩聚作用,将介体和酶共同固定在电极上,制成的过氧化氢传感器有良好的稳定性和充分的电子流动性,对1.0μmol/L~1.1mmol/LH2O2呈线性响应,检出限为0.5μmol/L 相似文献
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以二环己基碳化二亚胺为活化剂将葡萄糖氧化酶(GOD)共价键接在玻碳电极上, 伏安实验观察到酶与电极基体的直接电子传递, 有观电子传递速度常数约为1s^-^1, 过程归因于全酶中辅基FAD的氧化还原转变。Ag^+离子的存在强烈地阻碍酶辅基的还原, 这与该离子抑制酶活性的机理可能有联系。Ag^+的抑制作用可由EDTA处理或电化学处理而解除, GOD电极对氧和苯醌的电还原有催化作用。测定了苯醌同还原态GOD的化学反应速度常数, 并讨论用苯醌代替氧作为生物电催化中的电子传递体的优点。 相似文献
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Laurinavicius V Kurtinaitien B Liauksminas V Jankauskait A Simkus R Meskys R Boguslavsky L Skotheim T Tanenbaum S 《Talanta》2000,52(3):485-493
Partially hydrolyzed polyarbutin-containing benzoquinone groups were synthesized by using chemoenzymatic methods. This polymer was used as a mediator for the oxidation of pyrroloquinoline quinone-dependent glucose dehydrogenase. Polymer was covalently attached to the enzyme through the glucose moiety of the polymer and amine residues in the protein. Electrochemical studies show that the oxidized benzoquinone attached to the enzyme can act as a mediator for the reoxidation of the enzyme at carbon electrode surfaces. The apparent Michaelis constant and inactivation rate constant of the coupled enzyme were found to be similar to these parameters of the native enzyme. 相似文献
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Gluconic acid was obtained in the permeate side of the bioreactor with glucose oxidase (GOD) immobilized onto anion-exchange membrane (AEM) of low-density polyethylene grafted with 4-vinylpiridine. The electric resistance of the anion-exchange membranes was increased after the enzyme immobilization on the membrane. The gluconic acid productions were relatively low with the GOD immobilized by any method on the AEM. To increase the enzyme reaction efficiency, GOD was immobilized on membrane of AN copolymer (PAN) adjacent to an anion-exchange membrane in bioreactor. Uses of anion-exchange membrane led to selective removal of the gluconic acid from the glucose solution and reduce the gluconic acid inhibition. The amount of gluconic acid obtained in the permeate side of the bioreactor with the GOD immobilized on the PAN membrane adjacent to the AEM under electrodialysis was about 30 times higher than that obtained with enzyme directly bound to the AEM. The optimal substrate concentration in the feed side was found to be about 1 g/l. Further experiments were carried out with the co-immobilized GOD plus Catalase (CAT) on the PAN membrane adjacent to the AEM to improve the efficiency of the immobilize system. The yield of this process was at least 95%. The storage stability of the co-immobilized GOD and CAT was studied (lost 20% of initial activity for 90 d). The results obtained clearly showed the higher potential of the dual membrane bioreactor with GOD plus CAT bound to ultrafiltration polymer membrane adjacent to the AEM. Storage stability of GOD activity in GOD plus CAT immobilized on PAN//AEM membranes and on AEM. 相似文献
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生物功能电极 III. 葡萄糖氧化酶的电化学固定化研究 总被引:5,自引:4,他引:5
利用磷酸盐缓冲溶液中吡咯的电聚合, 将葡萄糖氧化酶(GOD)包埋在聚吡咯(PPy)基质中以构成生物功能电极。讨论了溶液pH和聚合电位对酶固定化的影响, 并用IR和交流阻抗谱对酶膜进行表征。GOD的固定化只有当pH>5.5时才能实现, 由此推测酶是以带负电的粒子嵌入PPy的。交流阻抗谱表明这一电极具有有界多孔电极的特征。探索了酶与电子传递体Fe(CN)_6~(3-)同时固定化的可行性。电化学固定化的GOD保持其生物催化活性, 酶反应表观上遵循Michealis-Menten动力学。 相似文献
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This paper uses scanning electrochemical microscopy (SECM) coupled with an intracellular standard addition method to quantify enzyme activity in single intact cells. In this work, peroxidase (PO) inside human neutrophils is chosen as the model system. Cells immobilized onto a silanized coverslip are perforated with digitonin to form micropores on the cell membrane. Hydroquinone (H(2)Q) and hydrogen peroxide (H(2)O(2)) as the enzyme substrates diffuse through the micropores into the cell interior. There, H(2)Q is converted into benzoquinone (BQ) by intracellular PO. BQ diffuses with a steady flux through the micropores from the cell interior onto the cell surface. The BQ near the cell surface is detected by the Au tip of SECM held at -0.3 V. When the tip is scanned laterally along the central line over the cell, a 2-D scan curve is obtained. Then, the intracellular standard addition method using ultramicroinjection with a submicrometer-sized micropipette tip is performed. After ultramicroinjection of a standard solution, another 2-D scan curve is recorded. The intercellular enzyme activity can be calculated from both peak current on two scan curves. This method to quantify PO activity in the cell environment has several obvious advantages: high sensitivity due to signal amplification via intracellular enzyme-catalyzed reaction and no sample dilution, no electrode fouling from adsorption of intracellular biological molecules, and no interference from electro-active compounds that can be directly oxidized at the SECM tip or from oxygen in the detected solution. 相似文献
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Jerome R. Robinson Corwin H. Booth Patrick J. Carroll Patrick J. Walsh Eric J. Schelter 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(19):5996-6004
Reaction of p‐benzoquinone (BQ) with a series of rare‐earth metal/alkali metal/1,1′‐BINOLate (REMB) complexes (RE: La, Ce, Pr, Nd; M: Li) results in the largest recorded shift in reduction potential observed for BQ upon complexation. In the case of cerium, the formation of a 2:1 Ce/BQ complex shifts the two‐electron reduction of BQ by greater than or equal to 1.6 V to a more favorable potential. Reactivity investigations were extended to other REIII (RE=La, Pr, Nd) complexes where the resulting highly electron‐deficient quinone ligands afforded isolation of the first lanthanide quinhydrone‐type charge‐transfer complexes. The large reduction‐potential shift associated with the formation of 2:1 Ce/BQ complexes illustrate the potential of Ce complexes to function both as a Lewis acid and an electron source in redox chemistry and organic‐substrate activation. 相似文献