共查询到20条相似文献,搜索用时 218 毫秒
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通过一步电沉积制备了石墨烯-金纳米复合膜修饰玻碳电极,并以此修饰电极为工作电极,采用差分脉冲阳极溶出伏安法测定环境水中痕量汞. 这种纳米复合膜结合了金纳米粒子和石墨烯两者的优势,能够增加异相电子转移速度和修饰电极对汞的富集能力,从而显著提高了电极的灵敏度和选择性. 这种修饰电极具有良好的分析性能:Hg(II)的分析曲线覆盖了0.2~5.0和5.0~30 μg/L两个线性范围,Hg(II)检测限(S/N=3)为0.030 μg/L. 此外,该修饰电极还表现出良好的稳定性和抗干扰性能,还被成功地应用于实际水样中Hg(II)的测定. 相似文献
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ω-巯基己酸自组装修饰金电极及其对叶绿素的催化氧化还原作用 总被引:2,自引:0,他引:2
用自组装技术以ω-巯基己酸(6-MHA)对金电极进行修饰。通过表面增强拉曼散射(SERS)光谱和电化学方法研究了6-MHA自组装单分子膜(SAM)在金电极表面的形成及由此引起的电极双电层电容的变化,并研究了该自组装单分子膜的结构模型及修饰电极对叶绿素的催化性能。结果表明,6-MHA在金电极表面能够形成一层自组装膜,并对叶绿素的氧化还原过程具有明显的催化作用。 相似文献
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基于荧光共振能量转移的原理,以修饰于核酸适体上的FAM作为能量供体,以氧化石墨烯作为能量受体,构建了荧光适体传感器,分别对不同浓度的胰岛素和多巴胺进行检测.结果表明,胰岛素的线性检测范围为0.05~10μmol/L,多巴胺的线性检测范围为1~500μmol/L,当胰岛素和多巴胺检测浓度相同时,胰岛素检测信号远强于多巴胺.对胰岛素和多巴胺分别进行特异性实验,发现该传感器对胰岛素和多巴胺有较强的特异性.说明基于荧光共振能量转移的核酸适体传感器不仅可实现多种物质的微量检测,还具有较强的选择性,在生物和医药检测领域应用前景广阔. 相似文献
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表面修饰纳米TiO2的贮氢合金电极的光充电行为 总被引:1,自引:0,他引:1
采用水解-沉淀法制备了锐钛矿结构的纳米级TiO2,研究了表面修饰TiO2的贮氢合金电极的光充电、循环伏安及交流阻抗特性.结果表明,表面未修饰TiO2的贮氢合金电极在光照下电极电位基本无变化,而表面修饰TiO2的贮氢合金电极在光照下,电极电位向负方向偏移,可达-0.835V,表明在光照射条件下电极表面有氢原子形成.电化学阻抗谱的结果也表明,表面修饰电极在光照时表面有吸附氢存在,并存在氢原子向贮氢合金内部的扩散过程.扫描电镜观察表明,表面修饰TiO2的贮氢合金电极在光充电后产生的氢原子被贮氢合金吸收引起膨胀,导致表面出现大量微裂纹. 相似文献
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Fabrication of patterned polyaniline microstructure through microcontact printing and electrochemistry 总被引:1,自引:0,他引:1
Fei Guan Miao Chen Wu Yang Jinqing Wang Rui Zhang Shengrong Yang Qunji Xue 《Applied Surface Science》2004,230(1-4):131-137
Polyaniline (PANI) microstructures on ITO glass surface were achieved by microcontact printing of self-assembled film and electrochemical polymerization in an aqueous monoaniline solution. The patterned microstructures of PANI were easily transferred to an adhesive tape surface, which could be applied in the area of plastic circuit application. Optical microscope, atomic force microscopy (AFM), lateral force microscopy (LFM) and X-ray photoelectron spectroscopy (XPS) were used to examine the topography and properties of patterned PANI films. Optical microscope and AFM results showed that the PANI microstructure has regular pattern and clear boundary, while LFM and XPS results implied that this microstructure was completely covered by PANI. The data suggested that the interfacial properties of the surface control the rate of electrochemical polymerization, and the polymerization rate on the modified ITO surface is higher than that on the bare ITO area. In our experiments, cyclic voltammetric method, potentiostatic method and chronopotentiometry method were employed to deposited patterned PANI films on octadecyltrichorosilane modified ITO substrate. 相似文献
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Mohammad Mazloum-Ardakani Abolfazl Naser-Sadrabadi Mohammad Ali Sheikh-Mohseni Ali Benvidi Hossein Naeimi Azam Karshenas 《Ionics》2013,19(11):1663-1671
In this paper, the electrochemical properties of a carbon paste electrode modified by a synthesized Schiff base, 2,2′-[1,4-phenylenediyl-bis(nitrilomethyl-idene)]-bis(4-hydroxyphenol), and carbon nanotubes were studied by cyclic voltammetry. The modified electrode was used as an electrochemical sensor for catalytic oxidation of dopamine (DA). Differential pulse voltammetry (DPV) of DA by this electrochemical sensor exhibited two linear dynamic ranges with a detection limit (3σ) of 0.42 μM. Also, the selectivity of the prepared electrochemical sensor was checked for determination of DA in the presence of uric acid (UA), folic acid (FA), and acetaminophen (AC). The DPV results indicate that the proposed sensor can be used for simultaneous determination of DA, UA, and FA and also simultaneous determination of DA and AC. Finally, the proposed electrochemical sensor was used for determinations of these substances in real sample. 相似文献
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The electrochemical and optical properties of transparent, two-dimensional macroporous gold film were investigated. Colloidal crystal templates were assembled onto indium-doped tin oxide (ITO) glass surface through vertical depositing method. Following gold electrodeposition, they were removed by dissolution with tetrahydrofuran (THF). The highly ordered macroporous gold array was achieved. It was characterized by scanning electron microscope (SEM) and ultraviolet visible (UV-vis) spectrophotometry. The optical transparency of the gold film was near 25% and fairly constant between 300 and 900 nm. The macroporous gold film electrode was mounted into a thin-layer transmission cell. The electrochemical response was evaluated by thin-layer cyclic voltammograms (CV) of the Fe (CN)63−/Fe (CN)64− couple. Thin-layer cell exhibits good shape of waves and nearly symmetric cathodic and anodic waves. E0′ value and n of TMPD+/TMPD (TMPD is acronyms for N,N,N′,N′-tetramethyl-p-phenylenediamine, and TMPD+ is its mono-cation radical) couple were determined. Furthermore, results demonstrated electrolytic equilibrium was faster reached in macroporous gold film than ITO electrode. 相似文献
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The surfaces of tin-doped indium oxide (ITO) thin films for polymer light-emitting electrochemical cells (LECs) were modified by oxygen plasma discharge. The properties of the ITO surfaces were evaluated by means of the measurements of X-ray photoelectron spectroscopy (XPS), contact angle, surface free energy and polarity. The influence of surface properties of the ITO thin films on the performance of polymer LECs was investigated in terms of the turn-on voltage, injection current and luminance. When oxygen plasma discharge was employed to modify the ITO surfaces, the surface properties of ITO are optimized due to the improvement of surface stoichiometry and the enhancement of wettability. And the improved surface properties benefited from the oxygen plasma discharge is observed to decay with the time after the plasma discharge. The difference in chemical composition, surface free energy and polarity between the non-treated and treated ITO surfaces appears to become smaller with the increase of the time after plasma discharge. In addition, the electrical and optical performance of the devices is found to become worse with the increasing time after plasma discharge on ITO substrates. The results demonstrate that the device performance strongly depends on the ITO surface properties and the ITO/organic interface characteristics. 相似文献
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Shao Su Xinpan Wei Yuanyuan Guo Yiling Zhong Yuanyuan Su Qing Huang Chunhai Fan Yao He 《Particle & Particle Systems Characterization》2013,30(4):326-331
A new kind of silicon nanowire (SiNWs)‐based nanoelectrode assembly, a gold‐nanoparticle‐decorated silicon nanowire array (AuNPs@SiNWsAr), is employed for the construction of high‐performance electrochemical sensors. Significantly, the electrochemical nanosensors are capable of sensitive detection of various electroactive molecules (e.g., dopamine (DA), ascorbic acid (AA), hydrogen peroxide (H2O2), and glucose). Further, DA molecules loaded on the surface of AuNPs@SiNWsAr preserve stable high electroactivity overnight without special protection, while free DA molecules may lose their biological activity due to severe oxidization in ambient environment. These findings may offer new opportunities for the design of high‐performance electrochemical nanosensors with high sensitivity and robust stability. 相似文献
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One-dimensional assemblies of Pt nanoparticles (NPs) with the size range of 10–20 nm have been synthesized via a simple hydrothermal route using soluble starch as both template and reducing agent. The formation mechanism of the product was studied in details. The electrochemical behavior of dopamine (DA) and ascorbic acid (AA) on the prepared one-dimensionally assembled Pt NPs modified glassy carbon electrode were studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques and showed satisfactory results for the simultaneous determination of DA and AA by resolving the overlapping voltammetric responses of DA and AA into two voltammetric peaks.
相似文献17.
We demonstrated enhanced surface plasmon resonance (SPR) detection by incorporating an indium tin oxide (ITO) layer on a thin gold film. Porous ITO layers were fabricated by e-beam evaporation and slanted deposition at room temperature and the ITO structure was optimized in terms of the surface roughness and the SPR curve characteristics. In sensing experiments, the results obtained by ethanol–water mixture test showed that SPR substrates with a porous ITO layer provided a notable sensitivity improvement compared to a conventional bare gold film, which is attributed to the nonlinear dispersion characteristic of surface plasmons. Our approach is intended to show the feasibility and extend the applicability of the porous ITO-mediated SPR biosensor to diverse biomolecular binding events. 相似文献
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D. Caschera F. Federici D. Zane F. Focanti A. Curulli G. Padeletti 《Journal of nanoparticle research》2009,11(8):1925-1936
Gold colloidal nanoparticles (AuNps), synthesized by gold chloride hydrate (HAuCl4) chemical reduction were used to realize a modified glassy carbon electrode (GCE). Different shapes and sizes were observed,
varying the molar ratio of HAuCl4 and polyvinylpyrrolidone (PVP). The electrochemical behaviour of different neurotransmitters and molecules of biological
interest (dopamine, caffeic acid, catechol, uric acid, epinephrine and serotonin) were investigated by cyclic voltammetry
(CV) at the AuNps modified GCE and a dependence of the electrochemical response on the size and the shape of the particles
was observed. The electrochemical responses were stable during time with a generic decreasing of the peak current after 10 days
ranging from 5–10% for catechol, uric acid and serotonine to 10–15% for the other analytes. A study on the electrochemical
interface of modified electrodes was also carried out by means of electrochemical impedance spectroscopy (EIS). 相似文献
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Thin film hexagonal gold grids as transparent conducting electrodes in organic light emitting diodes
F. Laurent M. Sam Christopher A. Mills Lynn J. Rozanski S. Ravi P. Silva 《Laser \u0026amp; Photonics Reviews》2014,8(1):172-179
Indium Tin Oxide (ITO) coated glass is currently the preferred transparent conducting electrode (TCE) for organic light emitting diodes (OLEDs). However, ITO has its drawbacks, not least the scarcity of Indium, high processing temperatures, and inflexibility. A number of technologies have been put forward as replacements for ITO. In this paper, an OLED based on a gold grid TCE is demonstrated, the light emission through the grid is examined, and luminance and current measurements are reported. The gold grid has a sheet resistance of 15 Ω□−1 and a light transmission of 63% at 550 nm, comparable to ITO, but with advantages in terms of processing conditions and cost. The gold grid OLED has a lower turn‐on voltage (7.7 V versus 9.8 V) and achieves a luminance of 100 cdm−2 at a lower voltage (10.9 V versus 12.4 V) than the reference ITO OLED. We discuss the lower turn‐on voltage and the uniformity of the light output through the gold grid TCE and examine the conduction mechanisms in the ITO and gold grid TCE OLEDs. 相似文献
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Amino ion implantation was carried out at the energy of 80 keV with fluence of 5 × 1015 ions cm−2 for indium tin oxide film (ITO) coated glass, and the existence of amino group on the ITO surface was verified by X-ray photoelectron spectroscopy analysis and Fourier transform infrared spectra. Scanning electron microscopy images show that multi-wall carbon nanotubes (MWCNTs) directly attached to the amino ion implanted ITO (NH2/ITO) surface homogeneously and stably. The resulting MWCNTs-attached NH2/ITO (MWCNTs/NH2/ITO) substrate can be used as electrode material. Cyclic voltammetry results indicate that the MWCNTs/NH2/ITO electrode shows excellent electrochemical properties and obvious electrocatalytic activity towards uric acid, thus this material is expected to have potential in electrochemical analysis and biosensors. 相似文献