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1.
通过改进的热溶剂胶体合成法制备了单分散的Ni12P5纳米粒子,并利用X射线衍射、透射电子显微镜、X射线光电子能谱、X射线能谱对Ni12P5纳米粒子的晶体结构、化学组成和形貌等进行了表征。基于单分散Ni12P5纳米粒子研制出的非酶葡萄糖传感器具有出色的性能,其快速响应时间小于3 s,检测范围广(0.002~4.2 mmol·L-1),灵敏度高达1 572 mA·L·mol-1·cm-2,检测限低至0.8 μmol·L-1。此外,该传感器在用于人体血液中葡萄糖的实际检测中取得了满意的效果。  相似文献   

2.
采用循环伏安法、微分脉冲伏安法、交流阻抗谱以及计时电流法等电化学方法,结合红外光谱、紫外-可见分光光度法、原子力显微镜、透射电子显微镜以及原子吸收光谱等辅助手段,表征了固定漆酶的聚苯胺-草酸钴纳米复合物的化学组成、结构和形貌,测试了纳米复合物固酶前后的导电性能的变化,研究了纳米复合物修饰电极上固定漆酶的直接电化学行为,评估了该电极的催化氧还原效能以及作为电化学传感器检测氧分子的性能。实验结果表明该电极在不含电子介体的溶液中以酶活性中心T2作为首要电子受体,将得到电子传递给化学吸附的氧气使其被电还原,其表观电子迁移速率为0.017 s-1,且具有良好的催化氧还原性能(氧还原起始电位:460 mV vs NHE,转化氧分子为水的表观速率常数为2.6×10-4 s-1),酶电催化氧还原为水分子步骤为反应的速控步。该电极作为电化学传感器对氧具有极低检测限(0.20 μmol·L-1),宽线性响应范围(0.4~7.5 μmol·L-1)以及对底物高亲和力(KM=122.4 μmol·L-1)等优势。  相似文献   

3.
结合Cu(Ⅱ)离子浸渍吸附方法及直流电弧等离子体喷射化学气相沉积技术制备了一种电化学/电生理双模Cu2O/Cu-垂直石墨烯微电极,并研究了电化学方法检测尿酸以及记录脑电信号的双响应性能。使用扫描电子显微镜、透射电子显微镜、X射线衍射仪表征了形貌、微结构及晶体成分,并测试了电化学及脑电记录能力。结果表明,该微电极直径仅为200 μm,大量镶嵌Cu2O/Cu纳米粒子的石墨烯纳米片垂直生长在基片上,排列成了一种三维的多孔结构,使其具有了高的电化学催化活性、短程离子扩散路径、以及长程导电网络。由此,以10 μL的饱和NaCl溶液为介质记录脑电信号时,该微电极的皮肤接触电阻低至约7.05 kΩ,生理电采集性能接近涂导电膏的商用湿电极。此外,该微电极还灵敏响应尿酸的氧化电流,检测浓度范围在0.5~500μmol·L-1,检测限低至0.024 μmol·L-1,且具有良好的抗干扰能力及长期稳定性。  相似文献   

4.
为设计高稳定性且高灵敏度的纯金属有机骨架(MOF)电化学传感器以检测多巴胺(DA),我们选用铟基 MOF [In(2-NH3-BDC)(2-NH2-BDC)]·1.5H2O(RSMOF-1,RSMOF=resistance switchable metal-organic framework,2-NH2-H2BDC=2-氨基对苯二甲酸)修饰玻碳电极(RSMOF-1/GCE)。制备的电极RSMOF-1/GCE的DPV测试结果显示其线性范围为0.990~663 μmol·L-1、检出限为0.770 μmol·L-1。在多种干扰物质如尿酸、尿素、葡萄糖和对乙酰氨基酚存在的条件下,RSMOF-1/GCE对 DA仍具有高的选择性。理论模拟结果显示,在RSMOF-1孔道内壁的—NH2可通过氢键增强与DA分子的相互作用,使RSMOF-1/GCE具有灵敏的电化学传感DA的性能。  相似文献   

5.
采用水热法和低温浸渍法制备了电子助剂还原石墨烯(rGO)和界面活性位点Ni(Ⅱ)共修饰的高效TiO2光催化剂(简称Ni(Ⅱ)/TiO2-rGO)。制氢性能测试结果表明:相比于TiO2和单独还原石墨烯复合的TiO2,经还原石墨烯与Ni(Ⅱ)协同修饰后的TiO2表现出更高的光催化制氢性能。其中,Ni(Ⅱ)/TiO2-rGO(0.1 mol·L-1)具有最高制氢性能,制氢速率达到77.0 μmol·h-1,分别是TiO2(16.4 μmol·h-1)和TiO2-rGO(28.0 μmol·h-1)的4.70倍和2.75倍。还原石墨烯助剂与Ni(Ⅱ)活性位点协同增强制氢性能的原理是:还原石墨烯作为电子助剂可以快速捕获和传输电子,Ni(Ⅱ)作为界面活性位点可以从溶液中捕获H+,提高界面反应速率,2种助剂协同作用加快了TiO2上的光生电子-空穴对的有效分离。  相似文献   

6.
利用刚性配体6-(3-吡啶基)间苯二甲酸(H2PIAD),制备了一种基于Mn (Ⅱ)的配位聚合物{[Mn (PIAD)(DMF)]·H2O}n1)。采用后合成Ag纳米颗粒的策略制备了复合材料(Ag@1)以提高葡萄糖传感的电催化活性。在优化的外加电位下,通过计时电流法评估了Ag@1修饰的玻碳电极(GCE)的电催化性能。配位聚合物1为在其表面的Ag纳米颗粒均匀分布提供了固定基质,而且Ag@1传感器可以最大限度地发挥Ag与1结合对葡萄糖氧化的电催化协同效应。结果表明,Ag@1修饰的GCE对葡萄糖的检测性能良好,检出限低(6.36 μmol·L-1),选择性和灵敏度好(166.71 μA·L·mmol-1·cm-2)。  相似文献   

7.
采用软模板法制备了氮化钨-钨/掺氮有序介孔碳复合材料(WN-W/NOMC),作为一种高比表面积且价格低廉的阴极氧还原反应催化剂。通过适量添加尿素来改变复合材料中的氮含量,在掺氮量为7%(w/w)时,实验发现材料能够保持完整有序介孔结构,测试其比表面积高达835 m2·g-1,透射电子显微镜(TEM)测试结果显示其催化颗粒均匀地分散在氮掺杂有序介孔碳载体上。在O2饱和的0.1 mol·L-1 KOH溶液中测试了材料的氧还原催化性能(ORR),显示其起始电位为0.87 V(vs RHE),极限电流密度为4.49 mA·cm-2,氧还原反应的转移电子数为3.4,接近于20%(w/w)商业Pt/C的3.8,说明该材料表现出近似4电子的氧还原反应途径。研究结果表明,WN-W/NOMC的催化性能虽然稍弱于商业铂碳(0.99 V,5.1 mA·cm-2),但其具有远超铂碳的循环稳定性和耐甲醇毒化能力。  相似文献   

8.
将Co3O4/ZnO针状纳米棒材料修饰到针灸针表面用于检测葡萄糖浓度的变化。首先采用水热法在针灸针表面得到Co(CO30.5(OH)·0.11H2O针状纳米棒前驱体,然后在500 ℃条件下退火3 h得到Co3O4针状纳米棒阵列。再采用浸渍法将预制备好的ZnO量子点修饰到Co3O4针状纳米棒表面,得到Co3O4/ZnO复合修饰的针灸针。研究发现此针灸针对葡萄糖具有较好的电流响应(2 264.27 μA·L·mmol-1·cm-2)、较快的响应速度(<4 s)及较低的检测极限(0.311 μmol·L-1S/N=3))。且该针灸针在用于检测人体模拟细胞液中葡萄糖浓度时,对抗坏血酸和尿素等表现出较强的抗干扰性。  相似文献   

9.
通过水热法合成了一个由三连接的2,3-喹啉二甲酸桥联扭曲的Cd2+八面体形成的二维层状配位聚合物[Cd(QDA)]n1)。该配合物发射出较强的蓝色荧光并具有很高的热稳定性和化学稳定性。更为重要的是,该配合物在乙醇分散体系中可快速识别痕量的2,4,6-三硝基苯酚和Fe3+离子,其对2,4,6-三硝基苯酚的淬灭常数(Ksv)和检测限(LOD)分别为6.61×104 L·mol-1和0.83 μmol·L-1,对Fe3+离子的淬灭常数和检测限分别为1.74×104 L·mol-1和2.70 μmol·L-1。  相似文献   

10.
将Co3O4/ZnO针状纳米棒材料修饰到针灸针表面用于检测葡萄糖浓度的变化。首先采用水热法在针灸针表面得到 Co(CO30.5(OH)·0.11H2O针状纳米棒前驱体,然后在500 ℃条件下退火3 h得到Co3O4针状纳米棒阵列。再采用浸渍法将预制备好的ZnO量子点修饰到Co3O4针状纳米棒表面,得到Co3O4/ZnO复合修饰的针灸针。研究发现此针灸针对葡萄糖具有较好的电流响应(2 264.27 μA·L·mmol-1·cm-2)、较快的响应速度(<4 s)及较低的检测极限(0.311 μmol·L-1S/N=3))。且该针灸针在用于检测人体模拟细胞液中葡萄糖浓度时,对抗坏血酸和尿素等表现出较强的抗干扰性。  相似文献   

11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.  相似文献   

12.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

13.
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   

14.
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   

15.
The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.  相似文献   

16.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

17.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

18.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

19.
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   

20.
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   

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