电聚合分子印迹传感器测定黑茶中芦丁的含量

以芦丁作为模板分子,邻氨基酚为功能单体,在金电极表面循环伏安法电聚合具有选择性识别芦丁的分子印迹膜。以Fe(CN)3-/4-作为探针分子,采用循环伏安法(CV)、差分脉冲伏安法(DPV)、交流阻抗法(EIS)研究了印迹膜的性能、分子印迹效应。优化了测定芦丁含量的条件,芦丁浓度在5.56×10-6~2.22×10-4mol·L-1范围内,其对数与峰电流呈线性关系,线性方程为:I(μA)=9.83 lgc(mol·L-1)+14.63,检出限为1.85×10-6mol·L-1,并比较了传感器对其结构相似化合物的选择性响应,发现传感器对芦丁检测具有良好的选择性。该传感器成功应用于黑茶中芦丁含量的测定。     

自组装分子印迹单层膜修饰电极对L-丝氨酸的检测

以电沉积多孔金膜为基底,L-丝氨酸为模板分子,L-半胱氨酸为功能单体构建了信号放大的自组装分子印迹单层膜修饰电极.电极对L-丝氨酸浓度响应的线性范围为5.0×10-6～2.0×10-4 mol/L,检出限为4.8×10-7 mol/L,灵敏度为215 mA·L·mol-1.由于多孔金膜有效增加了模板分子的固定量,印迹电极响应性能较无多孔金膜修饰的印迹电极有明显提高.     

电聚合分子印迹传感器选择性测黑茶中槲皮素的含量

以槲皮素作为模板分子,邻氨基苯酚作为功能单体,在金电极表面通过电聚合法,制备了具有选择性识别槲皮素的分子印迹传感器。采用循环伏安法、差分脉冲伏安法研究了印迹膜的性能、结构和分子印迹效应。对功能单体与模板分子的配比、洗脱时间和印迹时间等实验参数进行了优化,并与其结构相似的化合物芦丁的选择性响应进行了比较,发现该传感器对槲皮素分子具有良好的选择性。槲皮素浓度在6.0×10-6~1.0×10-4mol/L范围内与峰电流呈线性关系,线性方程为:I(μA)=27.79+9.48lgc(mol/L)(R=0.9939),检出限为2.0×10-6mol/L。用此传感器测定黑茶中槲皮素含量的结果较为满意。     

基于自组装与电聚合联用制备磺胺甲噁唑分子印迹传感器及特性研究

以磺胺甲噁唑为模板分子,甲基丙烯酸为功能单体,马来松香丙烯酸乙二醇脂为交联剂,采用自组装与电聚合相结合方法,制备了一种对磺胺甲噁唑具有特异性识别位点的分子印迹电化学传感器。通过循环伏安法(CV)、示差脉冲伏安法(DPV)和安培计时法(I-t)表征了该印迹传感膜的电化学性能。结果表明,该传感器具有良好的选择性和灵敏度。在5.0×10-6~2.4×10-3mol·L-1浓度范围内峰电流与浓度呈良好线性关系(R=0.9943);检测限1.67×10-7mol·L-1(S/N=3);达到稳定电流所用时间小于2s。利用此方法成功测定了药物中磺胺甲噁唑的含量。     

碳纳米管修饰电极分子印迹传感器的制备及其对氧乐果的测定

以氧乐果为模板分子,邻苯二胺为功能单体,在碳纳米管修饰的玻碳电极表面通过电聚合方法制成氧乐果分子印迹聚合物膜,用无水乙醇洗脱后制备出对氧乐果有特异响应的电化学传感器。通过循环伏安法和电化学阻抗法对分子印迹传感器的电化学性能进行表征。以K_3Fe(CN)_6为探针,采用差分脉冲伏安法研究了该分子印迹传感器的分析性能,建立了氧乐果的间接测定方法。结果表明,K_3Fe(CN)_6的相对峰电流与氧乐果浓度在1.0×10~(-7)~2.0×10~(-6)mol/L范围内呈良好的线性关系,检出限为3.6×10~(-8)mol/L。     

基于金纳米粒子及石墨烯量子点的四环素分子印迹电化学传感器研究

该文以四环素为模板分子,4-氨基苯硫酚(4-ATP)为功能单体,采用循环伏安法在金纳米粒子和石墨烯量子点复合材料修饰的玻碳电极表面电聚合分子印迹膜,制备四环素(TC)分子印迹传感器(MIPs/GQDs-AuNPs/GCE),并通过循环伏安法(CV)、电化学交流阻抗法(EIS)和线性扫描伏安法(LSV)等研究了其电化学响应性能。结果表明,该传感器对四环素具有良好的电流响应。在最佳实验条件下,TC氧化峰电流值与其浓度在2.0×10~(-8)～3.0×10~(-5) mol/L范围内呈良好的线性关系,相关系数为0.999 4,检出限为1.5×10~(-9) mol/L,加标回收率为97.9%～106%。该传感器稳定性好、响应灵敏、选择性高,具有良好的应用前景。     

基于石墨烯掺杂金纳米粒子的灭除威分子印迹电化学传感器的制备与性能研究

以灭除威(XMC)为模板分子,甲基丙烯酸(MAA)为功能单体,合成的马来松香丙烯酸乙二醇酯(EGMRA)为交联剂,在石墨烯掺杂金纳米粒子修饰玻碳电极表面合成分子印迹膜,研制了测定XMC的分子印迹电化学传感器。采用扫描电镜(SEM)对传感膜的形貌进行表征,通过循环伏安法(CV)、电化学阻抗谱法(EIS)和差示脉冲伏安法(DPV)对传感器的性能进行研究。DPV测试表明,XMC的浓度在1.0×10-7~2.0×10-5mol·L-1范围内呈良好线性关系,相关系数(r)为0.997 9,检出限(S/N=3)为1.5×10-8mol·L-1。选择性识别实验结果表明,XMC印迹敏感膜的印迹因子(β)达到2.94,相对于干扰物的选择因子(α)均大于1,对与XMC结构相似的速灭威的选择因子达到2.39,说明该印迹膜对XMC具有良好的选择性。识别过程动力学研究结果表明,石墨烯掺杂金纳米粒子分子印迹传感器的动力学结合速率常数k为73.05 s。将此传感器应用于蔬菜样品的加标回收检测,加标回收率为95.4%~108.0%。     

石墨烯修饰的三唑磷分子印迹电化学传感器的制备

采用石墨烯作为电极增敏材料,制备三唑磷(TAP)分子印迹电化学传感器。采用自由基聚合法,在石墨烯修饰电极(GR/GCE)上合成分子印迹聚合物膜(MIP)。利用微分脉冲伏安法、电化学阻抗谱对不同修饰电极进行电化学表征,利用微分脉冲伏安法考察了MIP和非分子印迹聚合物膜(NIP)传感器的电化学性能。在最优实验条件下,TAP浓度在1.0×10~(-7)～2.0×10~(-5)mol·L~(-1)内和MIP膜传感器峰电流呈线性关系,检出限为4.3×10~(-8)mol·L~(-1)(S/N=3)。建立MIP膜传感器的动力学吸附模型,测得结合速率常数k为9.0580 s。     

利用分子印迹传感器选择性测定绿麦隆

以绿麦隆为模板分子,邻氨基酚为功能单体,在金电极表面电聚合制得具有特异性识别孔穴的绿麦隆分子印迹膜。采用循环伏安、差分脉冲伏安法研究了印迹膜的性能、结构、分子印迹效应和模板分析物,并比较了传感器对其它结构相似化合物的选择性响应,发现该传感器对绿麦隆检测具有良好的选择性。绿麦隆浓度在3.0×10-7~1.5×10-6mol/L范围内与峰电流呈线性关系,检出限为1.0×10-7mol/L,在干扰物质共存情况下的回收率为105%~116%。     

水杨酸分子印迹电化学传感器的制备及其性能研究

以水杨酸作为模板分子,通过原位聚合法,在玻碳电极表面合成了水杨酸分子印迹聚合物膜,并用方波伏安法对该印迹电极进行了分析研究.当吸附时间为7 min时,印迹电极对水杨酸浓度响应的线性范围为1.0×10-5~2.6×10-5mol/L,检出限(S/N=3)为2.0×10-6mol/L,同一支印迹电极对水杨酸响应值的RSD为...     

Adsorption of Carbon Dioxide on Activated Carbon

The adsorption of CO2 on a raw activated carbon A and three modified activated carbon samples B, C, and D at temperatures ranging from 303 to 333 K and the thermodynamics of adsorption have been investigated using a vacuum adsorption apparatus in order to obtain more information about the effect of CO2 on removal of organic sulfur-containing compounds in industrial gases. The active ingredients impregnated in the carbon samples show significant influence on the adsorption for CO2 and its volumes adsorbed on modified carbon samples B, C, and D are all larger than that on the raw carbon sample A. On the other hand, the physical parameters such as surface area, pore volume, and micropore volume of carbon samples show no influence on the adsorbed amount of CO2. The Dubinin-Radushkevich (D-R) equation was the best model for fitting the adsorption data on carbon samples A and B, while the Preundlich equation was the best fit for the adsorption on carbon samples C and D. The isosteric heats of adsorption on carbon samples A, B, C, and D derived from the adsorption isotherms using the Clapeyron equation decreased slightly increasing surface loading. The heat of adsorption lay between 10.5 and 28.4 kJ/mol, with the carbon sample D having the highest value at all surface coverages that were studied. The observed entropy change associated with the adsorption for the carbon samples A, B, and C (above the surface coverage of 7 ml/g) was lower than the theoretical value for mobile adsorption. However, it was higher than the theoretical value for mobile adsorption but lower than the theoretical value for localized adsorption for carbon sample D.     

Growth of Single-walled Carbon Nanotubes on Substrates Using Carbon Monoxide as Carbon Source

The growth of single-walled carbon nanotubes(SWCNTs) on substrates has attracted great interests because of the potential applications in various fields. Carbon monoxide(CO) was used as the carbon source for the growth of SWCNTs on silicon substrates. Random or oriented SWCNTs can be produced by varying the CO flow rate. When the flow rate of CO was as low as 20 sccm(sccm:standard cubic centimeter per minute), dense SWCNT networks with clean surface were produced. When the flow rate was above 50 sccm, vertically aligned SWCNT(VA-SWCNT) arrays were grown. Well-aligned VA-SWCNT arrays were obtained in the temperature range of 650-800℃ and the content of large-diameter(above 1.7 nm) tubes in the array increased with the temperature. The height of the array was affected by the growth temperature, the CO flow rate, and the growth time. These findings indicate CO can be used as an efficient carbon source for the growth of SWCNTs on substrates under low flow rates.     

Adsorption of Carbon Monoxide on Oxidized Activated Lignin Carbon

Experimental data on the dynamics of carbon monoxide adsorption on oxidized activated lignin carbon are presented.     

碳纳米管含量对炭炭复合材料组织及力学性能的影响

炭纤维上原位合成了均匀生长且具有伸张形貌的碳纳米管,借助化学气相渗透制备了碳纳米管增强的炭炭复合材料,研究了不同含量的碳纳米管对炭炭复合材料组织和力学性能的影响。结果表明：炭纤维上生长碳纳米管改变了热解炭的沉积行为,诱导了各向同性热解炭的生成,且随着碳纳米管含量的增加,各向同性热解炭的厚度增加,但是复合材料的d002值却明显降低。微量的碳纳米管即可显著提高复合材料的力学强度,随着其含量的增加,复合材料的力学强度和模量迅速提高,但材料的断裂行为却急剧恶化,断裂模式由最初的假塑性断裂转变为脆性断裂。     

Electrochemical Biosensing Systems Based on Carbon Nanotubes and Carbon Nanofibers

Abstract

Carbon nanomaterials are in the forefront of research in a variety of chemical and physical disciplines. Of these, certain nanostructures seem to be suitable for the development of electrochemical biosensors. In particular carbon nanotubes, and carbon nanofibers have specific chemical and physical characteristics that lent them ideal for the development of biosensors with unique analytical characteristics. In particular, their conductivity, surface area, inherent and induced chemical functionalities, and biocompatibility provide the grounds for the development of a new era of electrochemical biosensors. In this review, we will examine the recent developments of biosensor design based on these new nanostructures.     

碳/碳复合材料碳源化合物乙苯热裂解机理的热力学研究

主要采用Gaussian 03程序中的密度泛函理论(DFT),在UB3LYP/6-31G*水平上对碳材料用碳源化合物乙苯的初期热裂解反应机理进行了研究.对反应物和产物的结构进行了能量梯度法全优化,计算了不同温度下(298～1573 K)的热力学参数.结果表明:在298～1573 K下,热力学首先支持生成甲苯自由基和甲基自由基的反应为主反应路径.低温下,生成苯乙基自由基(α位脱氢)的反应比例大于生成苯基自由基的反应,而高温下(823 K),生成苯基自由基的反应比例大于苯乙基自由基(α位脱氢)的反应.     

纳米碳管负载Co催化生长纳米碳管

In this paper, carbon nanotubes (CNTs) used as support and cobalt as catalyst to prepare new CNTs was studied. CNTs could grow well if the precursor CNTs were supported with Co on its surface. On the contrary, CNTs couldn’t grow at all if the precursor CNTs were not supported with Co. The TEM images showed that diameters of the obtained CNTs were different from those of the precursor CNTs. The pure CNTs could be prepared in this method without further purifying. The amount of Co on the precursor CNTs could affect the growth of CNTs greatly. When the content of metal on precursor CNTs was less than 16.2%, the amount of the obtained CNTs increased with the increasing amount of Co, and the maximum growth amount of 625% of CNTs could be obtained. But if the content of metal was more than 16.2%, the amount of Co had no influence on the growth of CNTs.     

碳源对鱼骨式纳米碳纤维及其负载的钯催化剂性能的影响

分别以甲烷、一氧化碳和乙烯为碳源合成了3种鱼骨式结构的纳米碳纤维(FCNF-C1,FCNF-CO和FCNF-C2),并作为载体制备了3种钯催化剂(Pd0.5%),考察了在对苯二甲酸加氢精制中的催化活性,通过N2吸附-脱附、X射线衍射、程序升温脱附、电子透射显微镜及CO化学吸附等方法对载体以及催化剂的结构进行了表征.结果表明,从不同碳源合成的纳米碳纤维(CNF)具有相似的直径和鱼骨式石墨层排列方式,但其物理化学性能差异较大,其中CO作为碳源得到的CNF具有最大的比表面积,最高的石墨化程度和最多的表面含氧基团;不同碳源的鱼骨式CNF负载的钯催化剂的活性为:Pd/FCNF-CO>Pd/FCNF-C1>Pd/FCNF-C2,与Pd分散度的顺序一致.CNF的织构、晶体结构和表面化学等协同载体效应,决定了Pd金属在CNF上的分散状态以及催化性能,而CNF的石墨层排列方式对其影响很小.     

活性炭上化学气相沉积法生长纳米碳纤维

利用流化床技术,以天然气为碳源,负载于活性炭上的纳米镍粒子为催化剂,在750 ℃下采用化学气相沉积法制备了气相生长纳米碳纤维(VGCNFs)/活性炭(AC)复合物。通过对样品进行XRD、激光拉曼光谱、扫描电镜和氮吸附检测,发现VGCNFs生长在活性炭的各个侧面上,以顶部生长模式为主,纤维的直径在40～120 nm之间,由于粗糙的纤维表面和石墨片层的翘曲而缺陷较多。VGCNFs/AC复合物与原料活性炭相比,BET比表面积从2 367 m²·g^-1降到了1 474     

Carbon on transition metal surfaces

The review surveys the conditions of formation and properties of four forms of surface carbon on transition metals, to wit, adsorbed atoms and clusters, surface carbide and graphite, and their role in the physical and chemical processes on the surface. The first-order phase transition in the adlayer, when graphite islands coexist with carbon gas, are considered. The effect of intercalation, when atoms (Cs, K, Na, Ba, Pt, Si) penetrate spontaneously under the graphite islands physisorbed on the metal, and its mechanism are discussed. An analysis is made of the poisoning of platinum-group metal catalysts in the reaction of dissociation, when graphite islands characterized by extreme adsorption and catalytic passivity form in the adlayer. The method of CsCl dissociation to probe the surface carbon is treated. Attention is drawn to the adsorption of a number of atoms (Cs, K, Ba, Pt) on a graphite monolayer on metals, and the properties of such systems are discussed. The effects observed in coadsorption of CsCl molecules with K, Na, Ba, Tm atoms on a graphite monolayer on metals are covered. By analogy with the bulk carbides, surface carbides of fixed stoichiometry and very strong metal-carbon bonding have been revealed to form on the surface of transition metals (W, Re, Mo). The effect of displacement of surface carbon into the bulk of the metal stimulated by the adsorption of some atoms (Si, S, O) is discussed. The carbon clusters adsorbed on metals are considered. The transport of surface carbon, its desorption and diffusion between the surface and the bulk of the metal with a single- and double-phase adlayer are reviewed.