氨基修饰介孔SiO2的合成及对其对Hg2+、 Ni2+和Mn2+的吸附

利用介孔SiO₂微球（MSM）作为基底,对其表面进行氨基修饰,合成了氨基修饰介孔SiO₂微球（MSM/NH₂）,其结构和性能经TEM, XRD和元素分析表征。结果表明：MSM/NH₂ 1.0［3-氨丙基三乙氧基硅烷（APTES）用量为1.0 mL］对Hg²⁺、 Ni²⁺和Mn²⁺的5次循环吸附效率的平均值均超过92.0%。     

血红蛋白在溶胶-凝胶纳米银修饰电极上的直接电化学

运用溶胶-凝胶技术将血红蛋白(Hb)固定于纳米银(AgNPs)修饰的玻碳电极(GCE)表面,制得溶胶-凝胶血红蛋白纳米银修饰电极(Sol-Gel/Hb/AgNPs/GCE)。优化了修饰电极的制备条件,研究了该修饰电极在B-R缓冲溶液(pH=4.10)中的电化学行为,探讨了Hb在AgNPs修饰电极表面的直接电子转移机理。结果表明:AgNPs不仅保持了Hb的生物活性,而且通过它的催化效应,实现了Hb与电极之间的直接电子转移。进一步的实验结果显示,固定在纳米银修饰电极表面的Hb能保持其对H2O2的生物电催化活性。     

一个基于5-(3-氨基-吡啶-4-基)-间苯二羧酸和桨轮状[Cu2(COO)4]簇的rtl-金属有机骨架材料的合成及其CO2选择性吸附性质

利用新配体5-（3-氨基-吡啶-4-基）-间苯二羧酸（NH₂-H₂L₁）,我们成功设计、合成了一例氨基功能化的柱-层型rtl-MOF,SNNU-Bai65。与原型MOF（SYSU）对比,极性官能团氨基对孔表面的功能性修饰和对孔道的分割使得SNNU-Bai65经活化后展现出更好的CO₂/N₂和CO₂/CH₄的选择性CO₂吸附性能。     

纳米银修饰电极差分脉冲伏安法测定盐酸金霉素

建立了快速测定盐酸金霉素(CTC)的方法。通过NaBH4还原法制备纳米银(AgNPs)溶胶,并利用X射线衍射和紫外-可见光谱进行表征。将制备好的AgNPs滴涂到玻碳电极表面制备修饰电极(AgNPs/GCE),研究了CTC在AgNPs/GCE上的电化学行为及伏安法测定,优化了缓冲溶液和pH等检测条件。结果表明,CTC在pH 3.3的柠檬酸-NaOH-HCl缓冲溶液中检测效果最佳。CTC在AgNPs/GCE上发生2个电子和2个质子的不可逆电化学氧化反应,且反应受吸附控制。最佳条件下,CTC的氧化峰电流与其浓度呈现良好的线性关系,线性范围为0.5~100μmol/L,检出限为0.14μmol/L。该修饰电极可用于河水样品检测。     

基于催化发卡自组装和 Ru(NH3)63+ 的核酸光电化学灵敏分析

基于催化发卡自组装反应（CHA）和电活性材料[Ru(NH₃)₆]Cl₃,发展了一种“信号增强”型光电化学生物传感器,实现了核酸的灵敏检测. 首先,采用逐层离子吸附法（SILAR）将CdS 固定于TiO₂/ITO 电极表面. 光电材料CdS 不仅能够将TiO₂ 的吸收范围从紫外光区拓展到可见光区,而且还能提高光电转换效率. 之后,通过Cd-S 键将捕获DNA（C-DNA）固定于CdS/ TiO₂/ITO 电极表面. 与此同时,将Au 结合的发卡DNA 探针1（Au-HP1）,发卡DNA 探针2（HP2）和目标DNA（T-DNA）混合物于溶液中进行CHA 反应,得到大量的Au-HP1:HP2 复合物. 再通过Au-HP1:HP2 复合物与C-DNA 的杂交反应将大量的双链DNA 引入到电极表面. 最后,将电活性物质Ru(NH₃)₆³⁺嵌入DNA 的磷酸骨架中,从而使得光电流大幅度的增强. 该光电生物传感器检测核酸的线性范围为10 fmol·L^-1 到 1500 fmol·L^-1,检测线为6.19 fmol·L^-1,在生物分析、新药筛选以及疾病的早期诊断等方面具有潜在的应用前景.     

基于纳米银/碳纳米纤维复合材料的增强效应电化学测定多贝斯

将银纳米粒子(AgNPs)电沉积在碳纳米纤维(CNFs)修饰玻碳电极表面制备纳米银/碳纳米纤维修饰玻碳电极(AgNPs/CNFs/GCE).采用扫描电镜考察其表面形态,在K3[Fe(CN)6]-K4[Fe(CN)6]体系中用循环伏安法和电化学阻抗法研究AgNPs/CNFs/GCE的电化学行为.采用循环伏安法和方波伏安法...     

基于Fe(Ⅲ)-2-氨基对苯二甲酸金属有机框架的免标记氯霉素电化学传感器的构建及应用

快速、简便的氯霉素(CAP)传感检测技术在食品安全和环境监测等领域具有良好的应用前景。本研究以FeCl₃·6H₂O和2-氨基对苯二甲酸(2-ATPA)为原料，采用水热合成法成功制备了金属有机框架(MOF)材料NH₂-MIL-88(Fe)，并利用2-ATPA配体上的氨基，将其共价固定在羧基化的玻碳电极表面；进一步利用磷酸基团(-PO₄^3–)与铁离子(Fe(Ⅲ))之间的强配位作用，将5′-PO₄^3–修饰的CAP核酸适配体(C-Apt)直接自组装到NH₂-MIL-88(Fe)修饰电极表面，无需额外交联剂和预活化过程，构建了一种新型C-Apt电化学传感界面。电化学实验结果表明，基于NH₂-MIL-88(Fe)的类过氧化物酶活性，NH₂-MIL-88(Fe)修饰电极对H₂O₂/3,3′,5,5′-四甲基联苯胺(TMB)表现出明显的电催化...     

Burkholderia Cepacia脂肪酶在氨基功能化离子液体修饰的SBA-15上的共价固定

合成了氨基以及氨基功能化离子液体修饰的介孔材料SBA-15(NH₂-SBA和NH₂-IL-SBA), 并以戊二醛为活化剂对NH₂-IL-SBA进行活化处理(CA-NH₂-IL-SBA), 通过元素分析、 N₂吸附-脱附、 X射线衍射、 红外光谱等方法研究了修饰及活化对SBA-15结构的影响. 将所得新型固定化载体用于Burkholderia cepacia脂肪酶(BCL)的吸附固定、 共价交联固定及聚集包被固定. 以三乙酸甘油酯的水解为模型反应, 考察了固定化BCL的酶活、 最适反应条件、 稳定性等酶学性质. 结果表明, 离子液体修饰后的载体保持了原有的孔道结构, 与氨基修饰以及原粉SBA-15吸附固定的BCL(BCL-NH₂-SBA和BCL-SBA-15)相比, 其固定化酶的比活力和稳定性都得到了明显提高, 对温度及低pH的敏感性降低. 其中聚集包被固定的BCL在获得了相对较高酶负载量的同时显示了最好的稳定性, 其热稳定性和重复使用性分别为BCL-SBA-15的4倍和2倍.     

石墨毡载纳米δ-MnO2高性能除铵净水材料研究

首先制备了α-MnO₂纳米花簇、β-MnO₂纳米针和δ-MnO₂微米颗粒三种不同晶型的MnO₂粉末材料，对其结构、形貌及吸附除铵能力进行了表征和测试.结果表明，层间距（7.2Å）大于NH₄⁺直径（2.96Å）和水合NH₄⁺直径（6.62Å）的δ-MnO₂相比其他两种晶型的MnO₂有更高的NH₄⁺吸附量；接着研究采用KMnO₄原位氧化还原法在石墨毡（GF）上直接生长超薄δ-MnO₂纳米片（MnO₂NPs）阵列构筑了石墨毡载纳米MnO₂（MnO₂NPs/GF）多级结构材料，制备简单，无须成型造粒就可直接用作除铵净水材料，研究结果表明，MnO₂NPs/GF不仅具有较高的吸附量（15 mg·g^－1）与良好的选择性，同时还展现了优异的快速吸附和稳定的循环使用性能.MnO₂NPs/GF对水中NH₄⁺的吸附符合准二级动力学模型，其吸附等温线符合Langmuir吸附等温式，是吸附-离子交换法除铵的理想材料.     

钛改性对γ-Fe2O3选择催化还原脱硝性能强化机制的分子模拟研究

采用密度泛函理论（DFT）研究了典型过渡金属Ti掺杂改性对γ-Fe₂O₃选择催化还原（NH₃-SCR）脱硝性能强化影响的作用机制。构建了单Ti和双Ti在γ-Fe₂O₃（001）表面的不同Fe位置的掺杂模型，计算了表面掺杂形成能，探讨了O₂、NO和NH₃分子在Ti掺杂前后的γ-Fe₂O₃（001）表面的吸附特性，并进行了反应机理分析。结果表明，单Ti倾向于掺杂在八面体Fe_oct位，双Ti倾向于两个Fe_oct位。Ti的掺杂增强了催化剂表面对O₂的吸附能力，吸附性能随Ti掺杂量增加而增强。单Ti和双Ti的掺杂都抑制了NO以N端在催化剂表面的吸附。Ti能够强化NH₃的吸附，增强了Lewis酸位，有利于SCR反应。Ti的掺杂增大了NO₂生成的反应能垒，降低了γ-Fe₂O₃低温区的SCR反应。Ti的掺杂抑制了NH和N的形成，避免了NH₃的过度氧化，提高NH₃的利用率，有利于SCR反应，并且抑制了通过E-R机理产生的N₂O，具有良好的N₂选择性。Ti的掺杂能够改善γ-Fe₂O₃在NH₃-SCR中还原NO的性能。     

ITO基底上ZnO薄膜的制备以及刻蚀图形的扫描电化学显微镜表征

在氧化铟锡(ITO)导电玻璃的衬底上,利用直接电沉积方法制备了ZnO纳米线或ZnO薄膜.然后利用存储有HCI刻蚀剂的琼脂糖微图案印章对其进行了化学刻蚀以形成不同的图形.利用扫描电子显微镜(SEM)、X射线衍射(XRD)和扫描电化学显微镜(SECM)分别对ITO衬底上的ZnO薄膜的结构、形貌和电化学性质进行表征.     

Surface modification of indium tin oxide via electrochemical reduction of aryldiazonium cations

The facile deposition of para-substituted aryl films onto indium-tin oxide (ITO) electrodes by the electrochemical reduction of aryl diazonium salts in acetonitrile is reported. For the deposition conditions used in this report, the aryl film thicknesses are on the order of 1-6 nm, suggesting a multilayer structure. Regardless of the functional group on the aryl diazonium cation, (NO(2), CO(2)H, or fluorene) the electrodeposition behavior onto ITO electrodes is similar to that seen on other electrode materials. XPS and UV-vis data support the introduction of organic functional surface groups to ITO. The blocking behavior of the aryl films on ITO toward the Ru(NH(3))(6)(3+/2+) redox couple is in agreement with electron transfer through conjugated organic layers. The facile preparation of patterned aryl films with regular-spaced 700 nm voids on ITO is also described. Atomic force microscopy and scanning surface potential microscopy on patterned NO(2) aryl films are used to assess the molecular structure and orientation. A 100 mV decrease in the contact potential over NO(2) aryl films relative to bare ITO suggests that the aryl films are loosely structured as deposited with the NO(2) groups oriented at a small angle away from the ITO surface.     

Preparation of a Novel NH2 + Ion Implantation Modified Electrode and Its Study of the Electrochemical Behavior of Hemoglobin

Abstract

A novel functional electrode was obtained by implanting NH₂ ⁺ into ITO film (NH₂/ITO) for the first time. The NH₂/ITO surface showed a better affinity to gold nanoparticles than bare ITO. Gold nanoparticles were deposited on the surface of NH₂/ITO electrode (Au/NH₂/ITO). The Au/NH₂/ITO and NH₂/ITO electrodes were used to observe the electrochemical behavior of Hemoglobin (Hb) immobilized on the electrodes surfaces. The peak current value of Hb immobilized on NH₂/ITO increased compared with on bare ITO while peak current value of Hb immobilized on Au/NH₂/ITO increased compared with on Au/ITO. Linkage between the ‐NH₂ implanted into the ITO film and the ‐COOH of Hb was thought to be the reason for the increase of active Hb coverage on NH₂/ITO compared with bare ITO. Increase of active Hb coverage on Au/NH₂/ITO compare with Au/ITO was attributed to the different amount of gold nanoparticles deposited. Results showed the novel NH₂/ITO and Au/NH₂/ITO electrodes exhibited good stability, reproducibility besides selectivity and sensitivity. The electrode process of Hb immobilized on Au/NH₂/ITO was quasi‐reversible with adsorption. The electrode reaction rate constant k_s and other related constants were determined. X‐ray photoelectron spectroscopy (XPS), field‐emission scanning electron microscopy (FE‐SEM), and impedance spectra were used to characterize the different surfaces.     

Gold nanoparticles attached NH2+ ion implantation-modified indium tin oxide electrode: Characterization and electrochemical studies

An NH2+ ion implantation-modified indium tin oxide film was prepared and the implantation of amino groups on the indium tin oxide substrate was verified by X-ray photoelectron spectroscopy analysis.The gold nanoparticles attached surface could be obtained by self-assembly of different sized colloidal gold nanoparticles onto the NH2+ ion implantation-modified indium tin oxide surface.By scanning electron microscopy and electrochemical techniques,the as-prepared AuNPs attached NH2+ ion implantation-modified indium tin oxide electrode was characterized and compared with bare indium tin oxide electrode.Using a [Fe(CN)6]3 /[Fe(CN)6]4 redox probe,the increasingly facile heterogeneous electron transfer kinetics resulting from the attached gold nanoparticle arrays was observed.The gold nanoparticle arrays exhibited high catalytic activity toward the electro-oxidation of nitric oxide,which could provide electroanalytical application for nitric oxide sensing.     

P3HT修饰一维有序壳核式CdS/ZnO纳米棒阵列复合膜的光电化学性能

采用电化学方法在铟锡氧化物(ITO)导电玻璃上制备了高度有序的ZnO纳米棒阵列, 在ZnO纳米棒阵列上先后电化学沉积CdS纳米晶膜及聚3-己基噻吩(P3HT)薄膜得到P3HT修饰的一维有序壳核式CdS/ZnO纳米阵列结构, 并通过扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)、能量散射X射线(EDX)等表征手段证实了该结构的形成. 以此纳米结构薄膜为光阳极组装新型半导体敏化太阳电池, 研究了CdS纳米晶膜的厚度和P3HT薄膜的沉积对电池光伏性能的影响, 初步探讨了电荷在电池结构中的传输机理, 结果表明, CdS纳米晶膜和P3HT薄膜的沉积有效地拓宽了光阳极的光吸收范围, 实验中电池的光电转换效率最高达到1.08%.     

Electrochemical determination of nitrate on Ag nanoparticles-decorated poly (direct blue 15) electrodes

In this study, for the first time, the electro-polymerization of Direct blue15 (DB15), an azo dye, was carried out on the surface of ITO. Furthermore, the poly(DB15) surface was electrochemically decorated with Ag nanoparticles (AgNPs), and the fabricated AgNPs/PDB15 electrodes were examined as nitrate sensors. Compared to unmodified ITO electrode, the AgNPs/PDB15 electrode had greatly improved electrochemical response to nitrate reduction. The nitrate determination in a linear range from 1.0×10⁻⁵ mol L⁻¹ to 2.27×10⁻³ mol L⁻¹ was performed with a detection limit of 9.66 μM. The synthesized electrode is a promising sensor for the electrochemical detection of nitrate pollutants in water.     

A study on electrodeposited of ZnO/ZnS heterostructures

ZnO/ZnS heterostructures were synthesized by a two steps electrochemical deposition method. Firstly, ZnS layer was deposited from an aqueous solution containing Na₂S₂O₃ and ZnSO₄ onto indium-doped tin oxide (ITO) coating glass substrate at two deposition potentials. Then, ZnO nanostructures were deposited from an aqueous solution of Zn(NO₃) onto ZnS surface. The as-obtained samples were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), Raman and UV-visible analysis. The results indicate that the electrodeposition of ZnS layer at ?0.9 V give the best proprieties of ZnO/ZnS heterostructures. Homogeneous and uniform surface of ZnO/ZnS heterostructure was confirmed by AFM images. The XRD patterns indicates a high crystallinity of ZnO/ZnS. A high transmittance of 65% was also noted from UV-Visible spectra and band gap energy as large as 3.6?eV was found.     

The adsorption of methamphetamine on Ag nanoparticles dispersed in agarose gel – Detection of methamphetamine in fingerprints by SERS

Surface-enhanced Raman scattering (SERS) has been used to investigate the adsorption of methamphetamine hydrochloride (MA) on AgNPs surfaces characterized by the dispersion of AgNPs on agarose gel (AgNPs/Agar). The AgNPs/Agar was characterized by transmission electron microscopy (TEM) as being formed by AgNPs with a mean diameter of 13.5 nm. The AgNPs/Agar films presented a surface plasmon resonance absorption band centered at 421 nm. SERS spectra, excited at 632.8 nm, of MA adsorbed onto AgNPs/Agar films were recorded for MA concentrations down to 1.0 × 10⁻⁵ mol L^-1. The results have also shown that MA adsorbs on the Ag surface forming ionic pairs with adsorbed chloride following a Frumkin adsorption isotherm with a ΔG_ads of −24 kJ mol^-1 and a g parameter characteristic of attractive lateral interaction. The AgNPs/Agar SERS substrate was further evaluated for MA detection on latent fingerprints (LFP). The AgNPs/Agar films prove to be a suitable substrate for recording fingerprints contaminated with MA making possible the detection of ca. 190 μg of MA, before and after LFP development. The SERS signal of MA adsorbed onto AgNPs/Agar films remained stable for at least 180 days.     

Electrochemistry of Azocrown Ethers in Langmuir-Blodgett Monolayers

Abstract

Monomolecular films of amphiphilic derivatives of crown ethers bearing an azo group in the macrocycle were prepared on surfaces of pure water and transferred onto electrodes using the Langmuir-Blodgett technique. The azocompounds studied were separated into Z and E stereoisomers. Monolayers of both isomers of azocrowns were transferred onto the surfaces of hydrophilic (thin mercury film electrode, TMFE) and hydrophobic (indium-tin oxide, ITO) electrodes. The electrode processes showed more reversible cyclic voltammetry profiles when mercury was used instead of ITO as the electrode substrate. This difference was ascribed to the different orientation of the molecules on the electrode surface.     

Surface modification and characterization of indium-tin oxide for organic light-emitting devices

In this work, we used different treatment methods (ultrasonic degreasing, hydrochloric acid treatment, and oxygen plasma) to modify the surfaces of indium-tin oxide (ITO) substrates for organic light-emitting devices. The surface properties of treated ITO substrates were studied by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), sheet resistance, contact angle, and surface energy measurements. Experimental results show that the ITO surface properties are closely related to the treatment methods, and the oxygen plasma is more efficient than the other treatments since it brings about smoother surfaces, lower sheet resistance, higher work function, and higher surface energy and polarity of the ITO substrate. Moreover, polymer light-emitting electrochemical cells (PLECs) with differently treated ITO substrates as device electrodes were fabricated and characterized. It is found that surface treatments of ITO substrates have a certain degree of influence upon the injection current, brightness, and efficiency, but hardly upon the turn-on voltages of current injection and light emission, which are in agreement with the measured optical energy gap of the electroluminescent polymer. The oxygen plasma treatment on the ITO substrate yields the best performance of PLECs, due to the improvement of interface formation and electrical contact of the ITO substrate with the polymer blend in the PLECs.