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1.
以不同阴离子表面活性剂作为添加剂种子生长法制备金纳米棒,并考察阴离子表面活性剂种类对金纳米棒形貌及光学性质的影响。在十二烷基苯基磺酸钠(SDBS)存在下,金纳米棒的产率明显高于使用十二烷基磺酸钠的反应体系。对添加SDBS的种子生长法制备金纳米棒的反应条件进行优化,得到十六烷基三甲基溴化铵、SDBS、抗坏血酸和硝酸银的最佳浓度分别为0.04 mol.L-1、2.4 mmol.L-1、1.2 mmol.L-1和0.08 mmol.L-1。在此条件下,金纳米棒的生长在30 min内完成,所制备的金纳米棒表面等离子共振吸收峰位于823 nm,其横纵比为(5±0.03)。当改变生长液中硝酸银浓度时,金纳米棒的尺寸也随之发生改变。此外,我们还探讨了SDBS的作用机理。相对于经典种子生长法,新方法制备纳米金棒在尺寸可调性、单分散性和生物毒性方面明显改善,可广泛应用于各种光学及生物分析。  相似文献   

2.
采用种子生长法制备金纳米棒(AuNRs)以构建光学传感器,用于Fe3+和Cu2+的高选择性快速可视化检测。在酸性环境中,Fe3+和Cu2+通过与KI溶液反应,将I-氧化成I2。I2刻蚀AuNRs,导致其纵向表面等离子体共振(LSPR)吸收峰蓝移,从而实现对Fe3+和Cu2+的检测。结果表明,反应温度为50℃时,添加0.8 mL 0.1 mol·L-1 HCl、2 mL AuNRs生长液和20 mmol·L-1 KI溶液,与2 mL 500 μmol·L-1 Fe3+或30 μmol·L-1 Cu2+反应25或90 min,可将AuNRs刻蚀至LSPR吸收峰消失。该方法对Fe3+和Cu2+检测具有高选择性和准确性,对于Fe3+、Cu2+共存体系的检测,可通过加入适量F-与Fe3+生成配合物[FeF6]3-完成对Fe3+的化学掩蔽,消除Fe3+的干扰,实现共存体系中Cu2+的准确检测。  相似文献   

3.
高比表面CexZr1-xO2复合氧化物的制备及表征   总被引:2,自引:0,他引:2  
分别采用共沉淀法和阴离子表面活性剂模板法制备了CexZr1-xO2复合氧化物。采用XRD、AFM、FTIR以及N2吸附-脱附等方法对样品进行了表征。结果表明,共沉淀法合成的样品在500 ℃煅烧2 h后,生成了立方相Ce0.75Zr0.25O2和四方相Ce0.5Zr0.5O2固溶体,比表面积为62.1 m2·g-1,孔体积为0.097 cm3·g-1;以阴离子表面活性剂十二烷基苯磺酸钠(SDBS)为模板剂,乙二胺为助模板剂合成的样品在500 ℃煅烧2 h后,生成了纯四方相Ce0.5Zr0.5O2固溶体,比表面积为180 m2·g-1,孔体积为0.182 cm3·g-1。结果表明,以阴离子表面活性剂SDBS为模板剂,可以合成高比表面积且具有介孔结构的Ce0.5Zr0.5O2复合氧化物;加入乙二胺作为助模板剂可明显的提高比表面积和孔体积。  相似文献   

4.
采用种子生长法制备金纳米棒(AuNRs)以构建光学传感器,用于 Fe3+和 Cu2+的高选择性快速可视化检测。在酸性环境中,Fe3+和 Cu2+通过与 KI溶液反应,将 I-氧化成 I2。I2刻蚀 AuNRs,导致其纵向表面等离子体共振(LSPR)吸收峰蓝移,从而实现对Fe3+和Cu2+的检测。结果表明,反应温度为50℃时,添加0.8 mL 0.1 mol·L-1 HCl、2 mL AuNRs生长液和20 mmol·L-1 KI溶液,与 2 mL 500 μmol·L-1 Fe3+或 30 μmol·L-1 Cu2+反应 25或 90 min,可将 AuNRs刻蚀至 LSPR 吸收峰消失。该方法对 Fe3+和 Cu2+检测具有高选择性和准确性,对于 Fe3+、Cu2+共存体系的检测,可通过加入适量 F-与 Fe3+生成配合物[FeF6]3-完成对 Fe3+的化学掩蔽,消除Fe3+的干扰,实现共存体系中Cu2+的准确检测。  相似文献   

5.
以柠檬酸三钠做稳定剂, 用硼氢化钠还原氯金酸制备了粒径为5 nm的纳米金. 用铅离子核酸适体aptamer保护纳米金获得了检测铅离子的适体纳米金(aptamer-NG)共振散射光谱探针. 在pH 7.0的Na2HPO4-NaH2PO4缓冲溶液中及30 mmol•L-1 NaCl存在下, aptamer-NG稳定而不聚集. Pb2+可与该探针中的aptamer形成非常稳定的G-四分体结构, 并释放出纳米金. 在NaCl作用下纳米金聚集形成较大的微粒, 导致552 nm处共振散射峰强度增大. Pb2+浓度在0.07~42 nmol•L-1范围内与552 nm处共振散射强度增大值ΔI成线性关系, 其回归方程为ΔI=12.0c+9.2, 线性相关系数为0.9965, 方法检出限为0.03 nmol•L-1 Pb2+. 该方法用于水样中铅离子检测, 结果与石墨炉原子吸收光谱法结果一致.  相似文献   

6.
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   

7.
C9pPHCNa与C10TABr混合水溶液的表面吸附和胶团形成   总被引:2,自引:0,他引:2  
羧酸盐Gemini表面活性剂C9pPHCNa与季铵盐表面活性剂十烷基三甲基溴化铵(C10TABr)混合水溶液的胶团生成能力、降低水表面张力的能力和效率均出现明显的增效. 当C9pPHCNa在溶液中的摩尔分数(α1)为0.33时,cmcT(临界胶团总浓度)、γcmc(临界胶团总浓度对应的表面张力)、c20,T(降低20 mN•m-1水表面张力所需的表面活性剂总浓度)这3个指标均达到最低值,分别为0.60 mmol•L-1、23.5 mN•m-1和1.58×10-5 mol•L-1. 在所有考察的溶液比例范围内,二组分在混合胶团和表面吸附层中的组成均接近等摩尔比,表现出强烈的分子间相互作用.  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.
首先通过水热过程在泡沫镍(NF)上生长出钼酸镍纳米棒阵列(NMO/NF),再依次利用水热硫化和气相磷化法改性钼酸镍纳米棒阵列获得三维自支撑析氢电催化剂(PS-NMO/NF)。研究表明,硫化作用诱导钼酸镍纳米棒阵列向类珊瑚球结构转变并形成具有高电化学活性表面积的无定形硫化物壳层,显著提高钼酸镍析氢反应(HER)活性。进一步磷化处理,表面形成的无定形磷酸盐与硫化物形成丰富的异质界面,促进了电子转移,进一步提升了电极的HER性能。在1 mol·L-1 KOH电解液中,电流密度为10 mA·cm-2时,PS-NMO/NF所对应的析氢过电势为93 mV; 100 mA·cm-2的电流密度所对应的析氢过电势仅为180mV,Tafel斜率为67 mV·dec-1,而且在20 h内可稳定运行,无明显衰减。  相似文献   

10.
外源Cu2+与烟草CuZnSODⅢ的相互作用   总被引:1,自引:0,他引:1       下载免费PDF全文
In this paper, we have studied the interaction of CuZnSODⅢ and Outer-Copper, enzyme activity experiments expressed that 0.1mmol·L-1 Cu2+ addition reduced the enzyme activity sharply, but this reduced action had not been found for the additions of 0.1mmol·L-1 1∶1 Cu2+ and Zn2+, and 0.1mmol·L-1 Zn2+, respectively. This was due to the Cu2+ exchanged the Zn2+ in CuZnSODⅢ,and it was proved by the experiment of determination of metal content. Meanwhile, the static fluorescence quenching mechanism revealed the exist of molecular complex of CuZnSOD with Cu2+. The binding constant was obtained from lineweaver-burk and double-lg plot. The distance of active site to Trp is about 2.83nm, was calculated according to F?rster theory.  相似文献   

11.
Controlled synthesis of asymmetrical gold nanokites was realized by reducing HAuCl4 with polyvinyl alcohol (PVA) in PVA‐sodium dodecyl sulfate (SDS) aggregations aqueous solution at room temperature without any additional reducing agents. The crystal structures, optical property and growth process of the gold nanokites were investigated by X‐ray diffraction (XRD), Vis‐NIR spectrum and transmission electron microscope (TEM). HAuCl4 concentration dramatically influenced the morphologies of the products. When HAuCl4 concentration was increased from 0.5 mmol·L−1 to 2.2 mmol·L−1, the products changed from network‐like nanostructures to nanokites, nanoleaves and microplates. SDS was indispensable for the formation of gold nanokites and without SDS super‐branched structures became the dominant products.  相似文献   

12.
In the present work a central composite design based on response surface methodology (RSM) is employed for fine tuning of the aspect ratios of seed-mediated synthesized gold nanorods (GNRs). The relations between the affecting parameters, including ratio of l-ascorbic acid to Au3+ ions, concentrations of silver nitrate, CTAB, and CTAB-capped gold seeds, were explored using a RSM model. It is observed that the effect of each parameter on the aspect ratio of developing nanorods highly depends on the value of the other parameters. The concentrations of silver ions, ascorbic acid and seeds are found to have a high contribution in controlling the aspect ratios of NRs. The optimized parameters led to a high yield synthesis of gold nanorods with an ideal aspect ratio ranging from 1 (spherical particle) to 4.9. In addition, corresponding tunable surface Plasmon absorption band has been extended to 880 nm. The resulted nanorods were characterized by UV–visible spectrometry and transmission electron microscopy.  相似文献   

13.
A sensitive and rapid method, without any extraction procedure, for the determination of the anionic surfactant expressed in the terms of sodium dodecyl benzene sulfonate (SDBS) by the resonance light scattering (RLS) technique is described in this paper. In the pH value 3.0 Britton-Robinson (BR) buffer, Victoria blue B (VBB) reacted with SDBS and produced large particles which resulted in the remarkable enhancement of the RLS intensity of VBB. The enhanced RLS intensity of the assay system was proportional to the concentration of SDBS in the range of 0.08–3.0 mg L–1 and the correlation coefficient was r = 0.9996. The detection limit was 0.013 mg L–1. This method was applied to determine the anionic surfactant in the surface water samples and satisfactory results were obtained. The reaction mechanism was also studied and the interaction between VBB and SDBS was mainly governed by electrostatic effect and the π–π stacking effect.  相似文献   

14.

The electrochemical behavior of cationic tetradecyltrimethylammonium bromide (TTABr), anionic sodium dodecylsulfate (SDS), cationic‐anionic (catanionic) mixed surfactant and self‐assembled solutions at Pt wire electrode has been studied by cyclic voltammetry (CV). On the basis of the cyclic voltammograms and determining the self‐assembled structures by using freeze‐fracture transmission electron microscopy (FF‐TEM), the mechanisms of the electrochemical reactions near the electrode for the two surfactant self‐assembled solutions, i.e., micelles and vesicles, are presented. When mixing TTABr and SDS, at the right mixing ratio of TTABr:SDS, vesicles are established spontaneously. The redox behavior of two vesicle‐phase solutions at a constant total concentration of 25 mmol·L?1 with the ratios of TTABr:SDS 9.35:0.65 of positive charges of bilayer membranes and 1.25:8.75 of negative charges of bilayer membranes are investigated by cyclic voltammetry. These cyclic voltammograms of vesicles with different charges are compared with those of 100 mmol · L?1 TTABr and 100 mmol · L?1 SDS micelle solutions. This CV study on surfactant self‐assembled solutions should open up a new method of study in surfactant science.  相似文献   

15.
一维金纳米粒子链的制备及其光学特性研究   总被引:2,自引:0,他引:2  
在没有模板存在的条件下, 只用表面活性剂为稳定剂, 制备了一维的金纳米粒子链, 详细考察了链状结构形成时各种试剂浓度、种类及其它外部条件对纳米粒子链形成的影响. 实验发现, 在HAuCl4 浓度1~5 mmol•L-1、十二烷基磺酸钠(SDS)浓度在2~8 mmol•L-1 (小于其CMC)范围内, 温度由60 ℃ 0.5 h内升高到100 ℃, 并在升温时间内分次将还原剂加完, 反应完成后不老化立即冷却到室温, 可以获得一维金纳米粒子链. 采用紫外可见光谱(UV-Vis)、同步光散射光谱和发射光谱等手段对金纳米粒子链的光学特性进行了研究, 用高分辨透射电子显微镜(HRTEM)研究了金纳米粒子的外观和粒径分布, 结果表明制备的金纳米粒子链是错落有致的链状结构, 结节处可以观察到金原子的排列晶格, 说明金纳米粒子的链状连接不是外部分子作用的结果; 表面等离子体共振吸收峰出现红移现象, 且随着链长的增加红移越明显; 具有非常强的光散射特性, 散射光强度比浓度相同的金纳米粒子高8倍; 发射光谱中明显观察到其三级散射, 表明其具有很好的非线性光学特性. 对金纳米粒子链的形成机理进行了探讨, 认为表面活性剂烷基亲油作用和金原子的聚集作用相互竞争是链状结构形成的原因.  相似文献   

16.
When the concentration of dodecyl benzene sulfonic acid sodium salt (SDBS) is 0.7 mmol·L?1, the electrochemical and electrochemiluminescence (ECL) intensity of Ru(bpy)32+‐chlorpheniramine maleate (CPM) system at the Au electrode were studied. The results showed that compared with the absence of SDBS, enhancement of the ECL intensity was 14‐fold at Au electrode. Base on this, an ECL method was established for efficient and simple determination of CPM at Au electrode. Under the optimum experimental condition, the enhanced ECL intensities had good linear relationship with the concentration of CPM in the range of 1.0×10?4–1.0×10?7 mol·L?1, and a linear regression equation was obtained as follows: I (counts)=48.805×106c+394.03 (r=0.9975), the detection limit for CPM was 1.4×10?8 mol·L?1. The RSD for 5 times determinations of 1.0×10?5 mol·L?1 CPM was 3.2%. The results of recovery test were between 96.3%–102.5%, and the RSD of recovery test (n=5) was 2.7%. In addition, eleven kinds of tertiary amines‐Ru(bpy)32+ systems were investigated in the absence and presence of SDBS. The results showed that the enhancement of SDBS on ECL intensity of tertiary amines‐Ru(bpy)32+ systems was universal.  相似文献   

17.
《Analytical letters》2012,45(17):3124-3137
Abstract

A terbium-sensitized fluorescence spectrophotometry method using an anionic surfactant, sodium dodecyl benzene sulphonate (SDBS), was developed for the determination of prulifloxacin (PUFX). It was found that SDBS significantly enhanced the fluorescence intensity of the PUFX–Tb3+ complex (about 13-fold). The optimal experimental conditions were determined as follows: excitation and emission wavelengths of 290 nm and 545 nm, pH 8.0, 4.0 × 10?5 mol L?1 terbium(III), and 4.0 × 10?4 mol L?1 SDBS. The enhanced fluorescence intensity of the system (ΔF) showed a good linear relationship with the concentration of PUFX over the range 6.0 × 10?8 to 2.0 × 10?6mol L?1 with a correlation coefficient of 0.9991. The detection limit (S/N = 3) was determined as 8.5 × 10?9 mol L?1. This method has been successfully applied for the determination of PUFX in pharmaceuticals and human urine/serum samples. Compared with most other methods reported, the rapid and simple procedure proposed here offered higher sensitivity, wider linear range, and good stability. The luminescence mechanism of the system was also discussed in detail. In the fluorescence system of PUFX–Tb3+–SDBS, SDBS acted not only as the surfactant but also as the energy donor.  相似文献   

18.
《Analytical letters》2012,45(10):1783-1795
The behavior of seven hydroxy anthraquinone derivatives was studied by capillary zone electrophoresis and micellar electrokinetic chromatography. The effects of buffer pH (6.5–10.8) and sodium dodecyl sulfate concentration (10–20 mmol L?1) on the effective mobilities of the analytes and their separation were tested. A comparison of the two optimized separation systems showed that micellar electrokinetic chromatography was superior as it permits separation of all the seven analytes within 15 min, using 15 mmol L?1 sodium dodecyl sulfate in 10 mmol L?1 tetraborate buffer, pH 8.5, at a voltage of 20 kV. The calibration curves were linear in the concentration range from 5.0 · 10?7 to 5.0 · 10?4 mol L?1 for most of the analytes, at a detection wavelength of 254 nm. LOD and LOQ values of the analytes were in the ranges of 2.10 · 10?7–1.28 · 10?6 mol L?1and 6.99 · 10?7–4.25 · 10?6 mol L?1, respectively. The proposed separation conditions were applied to determination of 1,2-dihydroxy anthraquinone (alizarin) and 1,2,4-trihydroxy anthraquinone (purpurin) in Rubia tinctorum aglycone and of the recently described 1-acetyl-2,4,5,7-tetrahydroxy-9,10-anthraquinone and 1-acetyl-2,4,5,7,8-pentahydroxy-9,10-anthraquinone in the mycelium of fungi Geosmithia lavendula.  相似文献   

19.
A novel bicaudate gemini surfactant was synthesized with anhydrous piperazine, chloride- bian, and 1-bromo dodecane as raw materials. Its structure was verified by infrared and 1H NMR. The surface active properties of the bicaudate gemini surfactant in water were measured at 55°C. Its critical micelle concentration (cmc) and γ cmc was 0.50 mmol · L?1 and 28.95 mN · m?1, respectively. Results indicate that there was not a remarkable difference in γcmc values between the synthesized bicaudate surfactant and conventional gemini surfactant N,N′–bis (dodecyl dimethyl ammonium bromide)-3-oxa-1,5-pentadiammonium. The sterilizing antimicrobial performance of the bicaudate gemini surfactant was examined. The bicaudate gemini surfactant show excellent inhibition against 18 types of bacteria compared with conventional monomeric surfactant and gemini surfactant at concentrations of 50 mg/L.  相似文献   

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