簇状纳米二氧化锰修饰玻碳电极电化学发光法测定己烯雌酚

基于簇状纳米二氧化锰可显著增强玻碳电极的导电性能,且己烯雌酚在该电极上能够增强鲁米诺体系的电化学发光,据此建立了电化学发光测定己烯雌酚的新方法。采用壳聚糖包覆的方法将簇状纳米二氧化锰固定在玻碳电极表面,考察了电极的稳定性以及影响电化学发光的因素。己烯雌酚浓度在3.5×10-11~6.5×10-9mol/L范围内,与电化学发光信号呈良好线性关系;检出限(3σ)为2.0×10-11mol/L。对4.0×10-10mol/L己烯雌酚进行11次平行测定,相对标准偏差(RSD)为1.1%。     

喷射式电化学发光流动检测技术快速测定奶粉及液态奶中三聚氰胺

采用喷射式电化学发光流动检测技术建立了奶粉和液态奶中三聚氰胺检测的新方法。在优化条件下,三聚氰胺浓度的负对数在1.0×10-9～1.0×10-3g/L范围内与其电化学发光强度呈良好的线性关系,检出限(S/N=3)为1.0×10-9g/L。不同加标量的阴性样品加标回收率为92.2%～114.2%,相对标准偏差为0.46%～1.2%。该方法具有检测灵敏、操作简单、样品用量少等优点,有望用于三聚氰胺的现场快速检测。     

CdS:Mn纳米棒的溶剂热合成与发光性质

近年来,一维纳米材料已成为广泛的研究热点.其中,Ⅱ-Ⅵ族掺杂半导体发光材料是一个重要的研究方向.研究者已通过不同的方法合成ZnS或CdS基掺杂纳米发光材料,以期得到基质与发光中心之间有效的能量传递,以及控制基质本身的缺陷发光.溶剂热便是其中一种较新的合成方法,通过它可以在相对温和的反应条件下得到均一的、结晶度较高的产品,在硫化物纳米发光材料的合成方面具有一定的优势.本文以乙二胺为溶剂,采用溶剂热方法制备出CdS︰Mn纳米棒,并系统研究了反应温度、硫镉比和反应时间对CdS︰Mn纳米晶的结晶度和发光性质的影响.(1)反应温度的影响.当[Cd(CH3COO)2]=0.0278mol·L-1,[TAA](硫代乙酰胺)=0.0556mol·L-1,[Mn(CH3COO)2]=0.000278mol·L-1时,分别在130,190,220,230,250℃恒温反应10h.随着反应温度的升高,CdS︰Mn纳米晶的结晶度逐渐提高.因为Mn2+掺杂进入CdS晶格,CdS纳米棒沿[001]晶向的生长优势逐步减弱并最终消失.在130～220℃之间,样品的发光强度变化不大.在220℃以上,样品的发光强度随反应温度的升高而迅速降低.(2)硫镉比的影响.当[Cd(CH3COO)2]=0.0278mol·L-1,[Mn(CH3COO)2]=0.000278mol·L-1时,改变TAA的浓度,分别采用0.5︰1,1︰1,1.5︰1,2︰1的硫镉摩尔比,在130℃恒温反应10h.发现随着硫镉比的提高,CdS︰Mn纳米晶的结晶度逐渐提高.当反应物中硫过量时,晶格缺陷以及表面悬空键数量降低,产品的发光强度随硫镉比升高而逐步提高.(3)反应时间的影响.当[Cd(CH3COO)2]=0.0278mol·L-1,[TAA]=0.0556mol·L-1,[Mn(CH3COO)2]=0.000278mol·L-1时,分别在130℃恒温反应1.5,2.5,4,6,10h.当反应时间少于4h时,CdS︰Mn纳米晶的结晶度迅速提高;而在4～10h之间,产品的结晶度变化不大.TEM图像显示了CdS︰Mn纳米棒的形成过程,只有当反应时间达到4h以上时,才能得到棒状产品.随着反应时间的延长,产品的发光强度先急剧降低,而后略微升高,这可能与纳米棒形成过程中产生的大量表面态有关.通过发光性质的研究,发现CdS基质的缺陷发光得到很好的抑制,产品在室温下即具有绝对优势的Mn2+发光(593nm),归于Mn2+的d-d(4T1-6A1)跃迁.激发光谱表明,本文所讨论的样品均显示出CdS基质的宽吸收,CdS基质与发光中心Mn2+之间存在有效的能量传递.综合考虑产品的形状与发光性质,当采用2︰1的硫镉比,不需要任何其他添加剂,在130℃反应10h制得Mn2+掺杂浓度为1%的CdS纳米棒,其在593nm附近的发光强度较强.CdS︰Mn纳米棒在纳米尺度电子和光子设备中具有潜在的应用价值.     

CdS：Mn纳米棒的溶剂热合成与发光性质（摘要）

近年来,一维纳米材料已成为广泛的研究热点.其中,Ⅱ-Ⅵ族掺杂半导体发光材料是一个重要的研究方向.研究者已通过不同的方法合成ZnS或CdS基掺杂纳米发光材料,以期得到基质与发光中心之间有效的能量传递,以及控制基质本身的缺陷发光.溶剂热便是其中一种较新的合成方法,通过它可以在相对温和的反应条件下得到均一的、结晶度较高的产品,在硫化物纳米发光材料的合成方面具有一定的优势.     

三聚氰胺修饰玻碳电极用于溶出伏安法测定水样中痕量银

用电化学沉积法将三聚氰胺修饰在玻碳电极上,应用此三聚氰胺修饰玻碳电极测定银时,试液在pH 4.6的乙酸-乙酸钠缓冲溶液中,在—0.45V处还原60 s,然后在0～+0.6V范围内扫描,使银离子从修饰电极上溶出,实现了水样中银离子的溶出伏安法测定,在+0.27V处可得银离子的氧化峰电位,银的浓度在6.0×10~(-9)～5.0×10~(-7)mol·L~(-1)范围内与其峰电流呈线性关系,检出限(3S/N)为1.0×10~(-9)mol·L~(-1)。方法用于实际水样中痕量银的测定,加标回收率在90.0%～96.0%之间。     

Electrochemiluminescence Biosensor for Glucose Based on Graphene/Nafion/GOD Film Modified Glassy Carbon Electrode

Glucose oxidase(GOD) was encapsulated in the Graphene/Nafion film modified glassy carbon electrode(GCE) and used as an ECL sensor for glucose. The GOD retains its bioactivity after being immobilized into the composite film. The sensor gives a linear response for glucose in the range of 2.0×10^?6–1.0×10^?4 mol/L with a detection limit of 1.0×10^?6 mol/L. The sensor showed good stability, the RSD for continuous scanning for 5.0×10^?5 mol/L glucose was 4.21 % (n=5). After being stored in 0.05 mol/L pH 7.4 PBS in 4 °C for two weeks, the modified electrode maintains 80 % of its initial activity. The glucose sensor provides new opportunity for clinical diagnosis applications.     

碳纳米管负载铂修饰玻碳电极用于电化学发光的研究及其对富马酸酮替芬的测定

在玻碳电极上制备了碳纳米管负载纳米铂修饰电极(Pt-MWCNTs/GCE)。考察了联吡啶钌和富马酸酮替芬在3个不同电极上的电化学及其发光行为,并对其进行了对比。结果表明,在Pt-MWCNTs/GCE上富马酸酮替芬对联吡啶钌的电化学发光强度有明显的增敏作用,其增敏效果约为MWCNTs/GCE电极的2倍,约为裸玻碳电极的3.5倍,据此,建立了一种Pt-MWCNTs/GCE电极上电化学发光法检测富马酸酮替芬的新方法。在优化实验条件下,富马酸酮替芬的浓度在1.0×10-7～1.0×10-4mol/L范围内与其相对发光强度呈线性关系,线性回归方程为I=48.805×106c+221.03(r=0.9969),检出限为2.4×10-9mol/L,连续平行测定1.0×10-5mol/L的富马酸酮替芬溶液5次,发光强度的RSD为3.3%。对样品进行回收率实验,回收率为99%～104%,RSD为2.1%。     

Electrochemical Determination of Tannins Using Multiwall Carbon Nanotubes Modified Glassy Carbon Electrode

A novel chemically modified electrode is prepared on the basis of the attachment of multiwall carbon nanotubes (MWNTs) to the surface of a glassy carbon electrode (GCE) in the presence of a hydrophobic surfactant. The electrochemical behavior of tannins at the MWNTs-modified GCE is investigated. Tannins yield a well-defined oxidation at about 0.30 V (SCE) at the MWNTs-modified GCE. MWNT-film shows remarkable enhancement effect on the oxidation peak current of tannins. The experimental parameters are optimized, and a direct electrochemical method to detect tannins is proposed. The oxidation peak current is proportional to the concentration of tannins over the range from 4 × 10^–7 to 2 × 10^–4 M, and the detection limit is 1 × 10^–7 mol/l after 5 min of accumulation. The relative standard deviation of 6% for determination of 2 × 10^–6 mol/l tannins indicates excellent reproducibility. The analysis method is demonstrated by using tea and Chinese gall samples.     

多壁碳纳米管修饰玻碳电极测定乙炔雌二醇

多壁碳纳米管修饰玻碳电极测定乙炔雌二醇;多壁碳纳米管;乙炔雌二醇;化学修饰电极;电化学测定     

多壁碳纳米管化学修饰电极测定替硝唑的研究

替硝唑(Tinidazole,TNZ)是继甲硝唑后新一代的抗厌氧菌和抗滴虫的国家级二类新药,可广泛应用于临床各种厌氧菌感染。其测定方法有紫外分光光度法、高效液相色谱法、光度法及电化学方法等。但用碳纳米管修饰电极测定TNZ还未见报道。     

Electrochemical Detection of 2-Nitrophenol Using a Glassy Carbon Electrode Modified with BaO Nanorods

Here, an electrochemical detection approach (differential pulse voltammetry) was employed to develop a 2-nitrophenol (2-NP) sensor probe using a glassy carbon electrode (GCE) coated by wet-chemically synthesized nanorods (NRs) of BaO. The prepared BaO NRs were characterized by field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and powder X-ray diffraction (XRD) analysis. The peak currents by differential pulse voltammetric (DPV) analysis of 2-NP are plotted against the concentration to obtain the calibration curve of the 2-NP detection. It was found to be linear from 1.5 to 9.0 μM, defined as the dynamic range (LDR) for 2-NP detection in phosphate buffer solution. The sensor sensitivity was calculated from the slope of LDR by considering the active surface area of NRs coated on GCE (0.0316 cm²) and found as 17.6 μAμM⁻¹ cm⁻². The limit of detection (LOD) was calculated as 0.50±0.025 μM from the signal/noise (S/N) ratio of 3. Moreover, the sensor analytical parameters such as reproducibility, long-term performing ability (stability), response time and validity in real environmental samples were found acceptable and to give satisfactory results. The development of a nanomaterial-based electrochemical chemical sensor might be an effective approach to sensor technology to detect carcinogenic and hazardous toxins for environmental safety and healthcare fields in a broad scale.     

Simultaneous Determination of Fat-Soluble Vitamins by Using Modified Glassy Carbon Electrode

Russian Journal of Electrochemistry - This study demonstrates the development of an electrochemical sensor based on β-cyclodextrin/multi-wall carbon nanotubes modified glassy carbon electrode...     

多壁碳纳米管-Nafion复合膜修饰玻碳电极测定硝苯地平的研究

研制了以Nafion分散羧基化多壁碳纳米管的化学修饰电极(Nafion-MWCNTs/GC),研究了硝苯地平(NIF)在修饰电极上的电化学行为和测定方法。实验结果表明,在0.1mol/LNH3-NH4Cl(pH9.6)溶液中,Nafion-MWCNTs/GC,对NIF具有明显的催化和增敏作用,还原峰电位由-0.85V(裸电极)正移到-0.75V(vs.AgCl/Ag)(修饰电极),灵敏度增加约7倍。对各种实验条件进行了优化。定量测定的线性范围为2.5×10-7~4.5×10-5mol/L,r为0.9974;检出限为8.0×10-8mol/L。探讨了NIF在Nafion-MWCNTs/GC上的电极过程和反应机理,测得在本体系中参与反应的质子数和电子转移数均为4,电子转移系数α为0.41。对NIF药片进行了测定,回收率为94.5%~101.0%。