聚茜素红功能化碳纳米管修饰电极对多巴胺和抗坏血酸的电化学研究

采用电聚合方法将茜素红非共价修饰到碳纳米管上,制备了聚茜素红/碳纳米管修饰电极.以多巴胺(DA)和抗坏血酸(AA)为模型化合物,研究该修饰电极的电催化作用.结果表明:电聚合法使茜素红牢固地修饰到碳纳米管上,能显著提高电极的灵敏度和分子识别性能.DA和AA的氧化峰位分离达240 mV.在AA的存在下,DA的差分脉冲伏安法峰电流在1×10-7～1×10-5 mol/L范围内呈良好的线性关系,检测下限达1×10-7 mol/L.     

非共价键法改性碳纳米管的研究进展

阐述了非共价键改性在碳纳米管功能化方面的应用进展,详细介绍了表面活性剂修饰、小分子的π-π堆积相互作用、聚合物的缠绕和包覆、生物大分子的包裹和吸附、内嵌填充修饰等改性方式的研究现状,并提出了非共价键法修饰碳纳米管未来改进的方向,探讨了不同修饰物与碳纳米管之间的相互作用机制。其中,含有共轭基团或芳基基团的聚合物,可以通过其共轭或芳基基团与碳纳米管间的π-π相互作用和范德华作用,实现对碳纳米管的非共价物理包覆。经聚合物功能化的碳纳米管在电池、催化剂、生物传感器和电化学装置上有较好的应用前景。此外,生物大分子对碳纳米管的非共价修饰不仅可以改善其在生物体系中的水溶性,而且通过合理设计还可以避免蛋白质、核酸等生物分子的非特异性吸附,从而得到具有特异性的生物分子-碳纳米管复合体系。     

水溶性磺酸钠苯基卟啉及其金属配合物共价与非共价修饰多壁碳纳米管的研究

合成了meso-四(4-磺酸钠苯基)卟啉及其Zn, Cu, Mn配合物, 通过共价与非共价的方法将其分别修饰到多壁碳纳米管上. 采用红外光谱对产物结构进行表征|通过透射电镜(TEM)考察了卟啉-多壁碳纳米管复合物的形貌特征|通过紫外光谱、荧光光谱对比分析了两类复合物, 发现在卟啉与多壁碳纳米管之间存在较强的电子效应, 同时发现非共价修饰的卟啉-碳纳米管复合物的荧光淬灭率更高|热重分析(TGA)表明非共价的卟啉-碳纳米管复合物中卟啉的含量比较高. 对修饰后的复合物进行了溶解性测试, 结果表明共价修饰的复合物在水中有较好的溶解性和分散性.     

聚苯胺共价接枝碳纳米管复合材料的制备及其超电容性能的研究

以氨基化的碳纳米管为基体, 通过低温原位聚合的方法将聚苯胺共价接枝于碳纳米管表面, 通过透射电镜(TEM)、X射线衍射(XRD)、紫外可见光(UV-vis)、傅里叶红外(FT-IR)、拉曼(Raman)及电化学方法对复合材料进行了表征. 结果表明通过低温原位聚合的方法可以使聚苯胺均匀接枝于碳纳米管表面. 电化学测试结果表明, 碳纳米管共价接枝聚苯胺作为超级电容器材料在0.5 A/g条件下聚苯胺的电容贡献值为754.8 F/g, 同时其倍率性能以及循环稳定性方面都明显优于聚苯胺非共价修饰的碳纳米管复合材料.     

金属卟啉有机共价和非共价修饰多壁碳纳米管

合成了5-(4-羟基苯基)-10,15,20-三苯基卟啉锌配合物, 与活化的多壁碳纳米管(MWNT)发生酯化反应, 从而得到金属卟啉有机共价化学修饰的多壁碳纳米管复合物; 利用金属卟啉环上的π电子与多壁碳纳米管管壁上的π电子通过π-π堆积效应, 得到金属卟啉有机非共价修饰的多壁碳纳米管复合物. 通过透射电镜(TEM)考察了金属卟啉-多壁碳纳米管复合物的形貌特征; 通过红外光谱对产物的化学结构进行了表征; 通过紫外光谱、荧光光谱和热失重分析(TGA)对比分析了两类复合物, 发现非共价修饰的金属卟啉-碳纳米管复合物的荧光淬灭率更高, 非共价修饰的金属卟啉-碳纳米管复合物中卟啉的含量比较高.     

银溶胶诱导多壁碳纳米管非共价表面修饰

利用银溶胶活化诱导淀粉螺旋结构实现了多壁碳纳米管非共价表面修饰. 实验结果表明, 淀粉非共价表面修饰的多壁碳纳米管在水中容易分散, 扫描电镜分析表明, 经银溶胶处理的多壁碳纳米管被单根分散在银溶胶溶液中. 酶解试验、IR和EDS分析表明, 碳纳米管表面修饰了一层淀粉.     

金属卟啉化学共价和非共价修饰多壁碳纳米管

合成了5-(4-羟基苯基)-10,15,20-三苯基卟啉锌配合物,与活化的多壁碳纳米管(MWNT)发生酯化反应,从而得到金属卟啉有机共价化学修饰的多壁碳纳米管复合物;利用金属卟啉环上的π电子与多壁碳纳米管管壁上的π电子通过π-π堆积效应,得到金属卟啉有机非共价修饰的多壁碳纳米管复合物.通过透射电镜(TEM)考察了金属卟啉-多壁碳纳米管复合物的形貌特征;通过红外光谱对产物的化学结构进行了表征;通过紫外光谱、荧光光谱和热失重分析(TGA)对比分析了两类复合物,发现非共价修饰的金属卟啉-碳纳米管复合物的荧光淬灭率更高,非共价修饰的金属卟啉-碳纳米管复合物中卟啉的含量比较高.     

功能化碳纳米管的电化学性质及在6-巯基嘌呤分析检测中的应用

采用修饰单壁碳纳米管(SWNT、SWNT-COOH或SWNT-OH)及多壁碳纳米管(MWNT、MWNT-COOH或MWNT-OH)的石墨电极研究配位阴离子[Fe(CN)6]3-和配位阳离子[Co(phen)3]3+的电化学行为与吸附性能,借助[Co(phen)3]3+在碳纳米管(CNT)的强吸附特性制备[Co(phen)3]3+/CNT/C修饰电极,以其应用于6-MP的分析检测.结果表明:1)在CNT修饰电极上[Fe(CN)6]3-/4-呈现很好的氧化还原可逆性,而[Co(phen)3]3+则显示明显的吸附控制特征.2)[Co(phen)3]3+在多壁碳纳米管修饰电极上的吸附量较单壁碳纳米管大,但经羧基化或羟基化后,吸附量减小,而且在羧基化表面的吸附量较羟基化的大.3)[Co(phen)3]3+与6-MP间存在明显的相互作用,其配位产物的还原峰电流与6-MP浓度呈线性关系.     

碳纳米管的化学修饰研究进展

介绍了近年来碳纳米管化学修饰(共价修饰和非共价修饰)方面的最新进展。参考文献47篇。     

利用糖芯片研究半乳寡糖与蓖麻凝集素和鸡冠刺桐凝集素间的相互作用

建立了用糖芯片技术研究寡糖与凝集素相互作用的方法.以新乳糖-N-四糖(LNnT)、乳糖-N-四糖(LNT)、λ-卡拉胶四糖(L4)和琼胶五糖(A5)为原料,经还原胺化法分别将其与1,2-十六烷基磷脂酰乙醇胺偶联得到拟糖脂,再将其与卵磷脂和胆固醇按4∶2∶5比例混合制备成脂质体后,用全自动芯片点样仪将其点印在硝酸纤维素膜包被的玻片上制成糖芯片,并进行寡糖与凝集素的结合实验.结果表明,蓖麻凝集素(Rieinus communis agglutinin 120,RCA120)特异性识别非还原端糖残基为Galβ(1 →4)的寡糖,而鸡冠刺桐凝集素(Erythrina cristagalli lectin,ECL)特异性识别非还原端糖残基为Galβ(1→4)GlcNAc的LNnT.采用接触式芯片点样仪制备糖芯片,并用荧光扫描仪对糖与凝集素结合信号进行检测,增加了灵敏度和准确性.本方法不仅适合于糖与蛋白相互作用的研究,也有助于加快糖类药物的发现.     

单层碳纳米管的化学修饰

单层碳纳米管 (SWNT)是 Iijima博士 [1]于 1 993年首次发现的 .它具有非常独特的物理和化学性质 ,因而成为近年来研究的热点问题 .随着单层碳纳米管的合成技术和纯化研究的不断完善 [2～ 5] ,关于它的研究方向开始转向化学反应和应用研究 .由于单层碳纳米管不溶于水或有机溶剂而限制了对其化学性质的研究 .单层碳纳米管的端头是由碳的五元环和六元环组成的半球形 .氧化作用可将该端头打开并转化为羧基 ,从而与其它的化学试剂发生反应 .Liu Jie等 [6] 用浓硫酸和浓硝酸的混合物氧化单层碳纳米管 ,将之裁剪成 1 50～ 80 0 nm的“短管”.在…     

Human fibrinogen adsorption onto single-walled carbon nanotube films

The adsorption behavior of human fibrinogen (Hfg) on single-walled carbon nanotube (SWNT) films was investigated using scanning electron microscopy (SEM) and near edge X-ray absorption fine structure (NEXAFS) spectroscopy. It was shown in the SEM images that fibrinogen was adsorbed strongly on the surface of SWNT when the samples were incubated in the Hfg solutions for 10 min. The dependence of adsorption on the concentration of fibrinogen was also investigated and it was found that adsorption increased with increasing concentration. In order to further explore the adsorption of fibrinogen on SWNT surface, NEXAFS spectra were obtained at the N K-edge and the C K-edge. The results confirmed the conclusion regarding the dependence of adsorption on fibrinogen concentration. It is demonstrated that, due to its high sensitivity to the surface elements, NEXAFS spectroscopy is a powerful tool to investigate the adsorption of fibrinogen on SWNT films.     

细胞色素c在单壁碳纳米管表面的固定、直接电子转移及电催化

应用吸附法将细胞色素c(Cytoc)固定在单壁碳纳米管(SWNT)表面.红外光谱(IR)显示被固定的Cytoc能保持原有的空间结构,没有发生变性.循环伏安测试表明,Cytoc在SWNT表面能发生稳定的直接电子转移,其i~E曲线上出现一对良好的、几乎对称的氧化还原峰.式量电位E0’基本不随扫速的增加而变化(在20 mV~120 mV/s的扫速范围内,E0’平均值为0.165±0.001V).实验同时给出,吸附在SWNT表面的Cytoc仍能保持其对H2O2电化学还原的生物电催化活性.     

Thermal annealing of SiC nanoparticles induces SWNT nucleation: evidence for a catalyst-independent VSS mechanism

Density-functional tight-binding molecular dynamics (DFTB/MD) methods were employed to demonstrate single-walled carbon nanotube (SWNT) nucleation resulting from thermal annealing of SiC nanoparticles. SWNT nucleation in this case is preceded by a change of the SiC structure from a crystalline one, to one in which silicon and carbon are segregated. This structural transformation ultimately resulted in the formation of extended polyyne chains on the SiC nanoparticle surface. These polyyne chains subsequently coalesced, forming an extended sp(2)-hybridized carbon cap on the SiC nanoparticle. The kinetics of this process were enhanced significantly at higher temperatures (2500 K), compared to lower temperatures (1200 K) and so directly correlated to the surface premelting behavior of the nanoparticle structure. Analysis of the SiC nanoparticle Lindemann index between 1000 and 3000 K indicated that SWNT nucleation at temperatures below 2600 K occurred in the solid, or quasi-solid, phase. Thus, the traditional vapor-liquid-solid mechanism of SWNT growth does not apply in the case of SiC nanoparticles. Instead, we propose that this example of SWNT nucleation constitutes evidence of a vapor-solid-solid process. This conclusion complements our recent observations regarding SWNT nucleation on SiO(2) nanoparticles (A. J. Page, K. R. S. Chandrakumar, S. Irle and K. Morokuma, J. Am. Chem. Soc., 2011, 133, 621-628). In addition, similarities between the atomistic SWNT nucleation mechanisms on SiC and SiO(2) catalysts provide the first evidence of a catalyst-independent SWNT nucleation mechanism with respect to 'non-traditional' SWNT catalyst species.     

QM/MD simulation of SWNT nucleation on transition-metal carbide nanoparticles

The mechanism and kinetics of single-walled carbon nanotube (SWNT) nucleation from Fe- and Ni-carbide nanoparticle precursors have been investigated using quantum chemical molecular dynamics (QM/MD) methods. The dependence of the nucleation mechanism and its kinetics on environmental factors, including temperature and metal-carbide carbon concentration, has also been elucidated. It was observed that SWNT nucleation occurred via three distinct stages, viz. the precipitation of the carbon from the metal-carbide, the formation of a "surface/subsurface" carbide intermediate species, and finally the formation of a nascent sp(2)-hybidrized carbon structure supported by the metal catalyst. The SWNT cap nucleation mechanism itself was unaffected by carbon concentration and/or temperature. However, the kinetics of SWNT nucleation exhibited distinct dependences on these same factors. In particular, SWNT nucleation from Ni(x)C(y) nanoparticles proceeded more favorably compared to nucleation from Fe(x)C(y) nanoparticles. Although SWNT nucleation from Fe(x)C(y) and Ni(x)C(y) nanoparticle precursors occurred via an identical route, the ultimate outcomes of these processes also differed substantially. Explicitly, the Ni(x)-supported sp(2)-hybridized carbon structures tended to encapsulate the catalyst particle itself, whereas the Fe(x)-supported structures tended to form isolated SWNT cap structures on the catalyst surface. These differences in SWNT nucleation kinetics were attributed directly to the relative strengths of the metal-carbon interaction, which also dictates the precipitation of carbon from the nanoparticle bulk and the longevity of the resultant surface/subsurface carbide species. The stability of the surface/subsurface carbide was also influenced by the phase of the nanoparticle itself. The observations agree well with experimentally available data for SWNT growth on iron and nickel catalyst particles.     

细胞在单壁碳纳米管无纺膜支架上的生长行为

以具有纳米拓扑结构特征的单壁碳纳米管无纺膜材料为支架, 选择在促进组织修复和再生中起重要作用的成纤维细胞株作为实验细胞, 研究了该材料对细胞生长行为的影响. 通过X射线光电子能谱分析, 表征其在细胞培养液中浸泡后的表面化学组成; 通过细胞粘附、增殖实验以及细胞骨架发育观察, 探讨了材料的微观纳米拓扑结构对细胞的作用, 以及与碳纤维、聚氨酯浇铸膜和空白培养板材料对细胞作用的差异和可能的机理; 并采用双层细胞培养装置, 研究了该材料通过细胞通讯途径对在其它材料上生长的细胞增殖的影响. 实验结果表明, 单壁碳纳米管无纺膜材料为细胞提供了十分接近天然细胞外基质的人造微环境, 具有显著促进细胞粘附和长时间增殖的功能, 而且生长在该支架上的细胞可能通过旁分泌方式将某些化学介质分泌到细胞外液中, 经局部扩散作用于在其它材料上生长的细胞, 促进它们的增殖.     

The First Principles Study of Li,Al and Ca Doped Zigzag(7,0) Single Walled Carbon Nanotube

We use the ab initio density functional theory to calculate the band structure, density of states, charge transfer, charge density difference, binding energy and vibration frequency. We can see that the conduction band through the Fermi level include SWNT/H_2/Li, SWNT/H_2/Al and SWNT/H_2/Ca, which shows a kind of metallic character. The charge distribution and contour plots of charge difference density of ion/H_2/SWNT show charge transfer between ion and H_2 molecules rather than between H_2 and H_2. Meanwhile, the interaction between Al, Ca and H_2 is weaker than that of Li. We can also prove that the ion is the primary reason to the increase of adsorption energy of hydrogen molecule in SWNT. Finally, we calculate the vibration frequency and don't find any imaginary frequency, which proves that the(7,0) SWNT is more stable.     

Immobilization and direct electrochemistry of cytochrome <Emphasis Type="BoldItalic">c</Emphasis> at a single-walled carbon nanotube-modified electrode

A single-walled carbon nanotube (SWNT)-modified electrode was fabricated and characterized by SEM and ac impedance techniques. The direct electrochemistry of cytochrome c (Cyt c), which was adsorbed on the surface of the SWNT, was studied by cyclic voltammetry. The results from cyclic voltammetry and infrared spectroscopy indicated that Cyt c remained in its original structure and did not undergo structural change after its immobilization on the SWNT. Further results demonstrated that the SWNT had promotional effects on the direct electron transfer of Cyt c and also indicated that the immobilized Cyt c retained its electrocatalytic activity to the reduction of H₂O₂. This modified electrode might be used in development of new biosensors and the biofuel cells.     

New Multifunctional Porous Materials Based on Inorganic–Organic Hybrid Single‐Walled Carbon Nanotubes: Gas Storage and High‐Sensitive Detection of Pesticides

Single‐walled carbon nanotubes (SWNTs) that are covalently functionalized with benzoic acid (SWNT‐PhCOOH) can be integrated with transition‐metal ions to form 3D porous inorganic–organic hybrid frameworks (SWNT‐Zn). In particular, N₂‐adsorption analysis shows that the BET surface area increases notably from 645.3 to 1209.9 m² g^?1 for SWNTs and SWNT‐Zn, respectively. This remarkable enhancement in the surface area of SWNT‐Zn is presumably due to the microporous motifs from benzoates coordinated to intercalated zinc ions between the functionalized SWNTs; this assignment was also corroborated by NLDFT pore‐size distributions. In addition, the excess‐H₂‐uptake maximum of SWNT‐Zn reaches about 3.1 wt. % (12 bar, 77 K), which is almost three times that of the original SWNTs (1.2 wt. % at 12 bar, 77 K). Owing to its inherent conductivity and pore structure, as well as good dispersibility, SWNT‐Zn is an effective candidate as a sensitive electrochemical stripping voltammetric sensor for organophosphate pesticides (OPs): By using solid‐phase extraction (SPE) with SWNT‐Zn‐modified glassy carbon electrode, the detection limit of methyl parathion (MP) is 2.3 ng mL^?1.