聚鲁米诺-镍(Ⅱ)复合物自组装膜修饰电极电化学法测定氢氯噻嗪

基于鲁米诺的电聚合效应和该聚合物与镍离子的配位效应,利用层层自组装技术,聚鲁米诺-镍(Ⅱ)复合膜可以层层修饰在石墨电极表面。与电聚合修饰电极相比,氢氯噻嗪在该修饰石墨电极上能够更强烈地增敏鲁米诺弱电化学发光信号。据此,建立了一种高灵敏测定氢氯噻嗪的电化学发光分析新方法,同时也提出了利用自组装膜修饰电极改善电极表面电化学发光微环境从而提高其分析特性的新思路。该方法测定氢氯噻嗪的检出限为3.0×10-6g/L,线性范围为7.0×10-6~3.0×10-3g/L,相对标准偏差为2.3%(n=9)。     

化学氧化合成聚(苯胺-鲁米诺)复合纳米线的电化学发光特性研究

以过硫酸铵为氧化剂,通过氧化苯胺和鲁米诺混合溶液合成了聚(苯胺-鲁米诺)复合纳米线。相对于鲁米诺425 nm处的最大荧光发射波长,复合纳米线中聚鲁米诺的最大荧光发射波长明显红移到465 nm处。采用简单的滴凃方式将聚(苯胺-鲁米诺)复合纳米线修饰于石墨电极表面,形成一层稳定的聚(苯胺-鲁米诺)复合纳米线膜。此聚(苯胺-鲁米诺)纳米线膜修饰电极呈现出良好的电化学发光特性,H2O2对化学合成的聚(苯胺-鲁米诺)纳米线电化学发光呈现出增敏效应。在优化实验条件下,修饰电极的电化学发光信号与H2O2在5.0×10#9~1.0×10#5mol/L范围内呈线性关系,检出限为2×10#9mol/L。     

基于聚(吡咯-鲁米诺-金)纳米复合材料的电化学发光传感器检测盐酸去氧肾上腺素

利用电沉积方法在石墨电极表面制备了聚(吡咯-鲁米诺-金)纳米复合材料,通过扫描电子显微镜(SEM)、电化学阻抗谱(EIS)、循环伏安法(CV)及电化学发光法(ECL)进行了表征。结果表明,采用电沉积方法可以将金纳米与聚(吡咯-鲁米诺)共同固定于电极表面;相对于聚(吡咯-鲁米诺)修饰电极,聚(吡咯-鲁米诺-金)修饰电极呈现出更强的ECL信号,且在中性介质中仍然有良好的ECL信号。盐酸去氧肾上腺素(PHE)对聚(吡咯-鲁米诺-金)修饰电极的ECL信号具有抑制作用,由此建立了一种在中性介质中测定PHE的ECL分析法。聚(吡咯-鲁米诺-金)修饰电极的ECL降低值与PHE浓度的对数值在1. 0×10~(-7)～1. 0×10~(-12)mol/L的范围内呈线性关系,检出限为2. 5×10~(-13)mol/L。     

还原石墨烯-碳纳米管-金纳米复合物的电化学发光过氧化氢传感器

以聚乙烯亚胺(PEI)为还原剂,采用一步还原法制备纳米金修饰的还原石墨烯-碳纳米管(AuNPs-rGO-CNTs)复合纳米材料。PEI同时作为交联试剂,使得AuNPs-rGO-CNTs复合物具有良好的成膜性质,能均匀的修饰到玻碳电极表面,制得AuNPs-rGO-CNTs修饰电极。基于过氧化氢(H2O2)作为鲁米诺-电化学发光(鲁米诺-ECL)体系的共反应试剂能显著增强鲁米诺的电化学发光信号,构建了AuNPs-rGO-CNTs复合物修饰的玻碳电极用于电化学发光测定H2O2的新方法。实验采用循环伏安法对传感器的修饰过程进行了表征。对测试底液中鲁米诺的浓度、pH等条件进行了优化,在最优实验条件下,该传感器的电化学发光信号强度与H2O2浓度在3.4×10-2~1.4×102μmol/L范围内呈良好的线性关系,检出限为1.1×10-2μmol/L。传感器适用于H2O2的测定。     

CdSe量子点修饰电极电化学发光法测定叶酸

制备了水溶性的CdSe量子点,用紫外光谱和荧光光谱对其进行了表征.并将其修饰到金电极的表面,得到了CdSe量子点修饰电极(CdSe/GE),研究了其电化学发光性质.结果表明:在强碱介质中,CdSe/GE对鲁米诺电化学发光具有增敏作用,在此发光体系中加入叶酸后,会产生进一步增强的电化学发光信号,由此建立了电化学发光检测叶酸的新方法.考察了缓冲溶液pH值、鲁米诺的浓度和扫速等条件对电化学发光强度的影响.在优化的实验条件下,叶酸在1×10~(-13)~1.1×10~(-4) mol/L浓度范围内与相对发光强度(ΔI)呈现良好的线性关系,检测限为6.0×10~(-14) mol/L(S/N=3),并用于市售叶酸片剂中叶酸的测定,得到令人满意的实验结果.     

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%。     

纳米金/碳纳米管复合材料修饰电极催化鲁米诺电致发光体系的研究

制备了纳米金/多壁碳纳米管(MWNT)复合材料修饰电极,并将此电极应用于鲁米诺电化学发光体系.电化学发光实验表明,此复合材料修饰电极同时具备了纳米金和碳纳米管的催化性能.此外通过电极活性表面积测算、电化学交流阻抗实验等方法研究了纳米金和碳纳米管在此体系催化过程中的作用.纳米金/碳纳米管修饰电极具有良好的重现性,可以广泛应用于鲁米诺电化学发光测定体系.     

两极隔离式双极电极的电化学发光行为及其分析特性研究

设计了一种两极隔离式双极电极电化学发光装置,并以此装置为基础,研究了电化学发光试剂鲁米诺在此装置中的电化学发光行为和分析特性。通过外加电场的诱导,可以在双极电极的两极富集、分离对应的阴、阳离子,使鲁米诺阴离子富集于双极电极的阳极端,待检测的阳离子富集于双极电极阴极端。根据鲁米诺在阳极端的电化学发光信号定量分析阴极端所富集的阳离子的总量。在最佳条件下,鲁米诺电化学发光信号与分析物浓度在1.0×10-9~1.0×10-8mol/L范围内呈线性关系,检出限达1.1×10-10mol/L。以此为基础,发展了一种电化学发光方法测定溶液电导的新方法。     

聚鲁米诺-金属离子复合物膜的电化学发光特性及其分析应用研究

建立了一种基于电聚合和配位效应构建聚鲁米诺-金属离子复合物膜修饰电极测定尿素的电化学发光分析新方法, 并且提出了一种优化聚鲁米诺电化学发光分析特性的新思路. 在最佳条件下, 增敏电化学发光信号与尿素的质量浓度在2.0×10-9—1.0×10-7 g/mL 范围内呈线性关系, 检出限为1.7×10-10 g/mL.     

基于磁性分子印迹修饰电极的氯霉素电化学发光分析法

基于氯霉素(CAP)强烈抑制Ru(bpy)23+/三丙胺体系的电化学发光(ECL)信号,构建了一种高灵敏检测水体中CAP的磁性分子印迹电化学发光传感器。以Fe3O4-Au磁性纳米粒子为载体,对氨基苯硫酚(4-ATP)和2-丙烯酰胺-2-甲基丙基磺酸(AMPs)作为双功能单体,二甲基丙烯酸乙二酯(EGDMA)作为交联剂,过硫酸铵(APS)作为引发剂,通过自组装在Fe3O4-Au磁性纳米粒子表面合成氯霉素分子印迹膜(MIPs)。以修饰该磁性分子印迹聚合物的磁性玻碳电极(MGCE)为CAP电化学发光传感器。在优化实验条件下,ECL信号变化值(ΔI=I0-Ip)随着CAP浓度的增大而增大,且ΔI与CAP浓度的对数在0. 010～100 ng/L CAP浓度范围内呈良好线性关系,相关系数(r)为0. 998 0,检出限为0. 010 ng/L。研究结果表明,该传感器对CAP的检测灵敏度高,选择性好,线性范围宽,具有良好的应用前景。     

Intensification of electrochemiluminescence of luminol on TiO2 supported Au atomic cluster nano-hybrid modified electrode

With TiO(2) nanoparticles as carrier, a supported nano-material of Au atomic cluster/TiO(2) nano-hybrid was synthesized. It was then modified onto the surface of indium tin oxide (ITO) by Nafion to act as a working electrode for exciting the electrochemiluminescence (ECL) of luminol. The properties of the nano-hybrid and the modified electrode were characterized by XRD, XPS, electronic microscopy, electrochemistry and spectroscopy. The experimental results demonstrated that the modification of this nano-hybrid onto the ITO electrode efficiently intensified the ECL of luminol. It was also revealed that the ECL intensity of luminol on this modified electrode showed very sensitive responses to oxygen and hydrogen peroxide. The detection limits for dissolved oxygen and hydrogen peroxide were 2 μg L(-1) and 5.5 × 10(-12) M, respectively. Besides the discussion of the intensifying mechanism of this nano-hybrid for ECL of luminol, the developed method was also applied for monitoring dissolved oxygen and evaluating the scavenging efficiency of reactive oxygen species of the Ganoderma lucidum spore.     

鲁米诺在铂电极上阳极电致化学发光的机理研究

研究了碱性鲁米诺溶液在多晶铂电极上的阳极电致化学发光(ECL)行为,观察到电极的预极化处理和溶解氧跟发光峰强度和峰形有直接关系。结合XPS谱图和Pt,Pt|S~a~d~s修饰电极的循环伏安特性,给出了鲁米诺阳极ECL两个发光通道的可能反应机理:(1)鲁米诺阴离子在表面有新鲜Pt原子的电极上氧化生成鲁米诺自由基,然后迅速与溶液中的氧反应形成0.22V(vs.Ag)处的发光肩峰;(2)电极表面的铂氧化物能加速原子态氧的发生过程,并增大0.60V(vs.Ag)附近ECL主峰的发光强度。     

Synthesis, characterization, and electrochemiluminescence of luminol-reduced gold nanoparticles and their application in a hydrogen peroxide sensor

It was found that chloroauric acid (HAuCl(4)) could be directly reduced by the luminescent reagent luminol in aqueous solution to form gold nanoparticles (AuNPs), the size of which depended on the amount of luminol. The morphology and surface state of as-prepared AuNPs were characterized by transmission electron microscopy, UV/visible spectroscopy, X-ray photoelectron spectroscopy, FTIR spectroscopy, and thermogravimetric analysis. All results indicated that residual luminol and its oxidation product 3-aminophthalate coexisted on the surface of AuNPs through the weak covalent interaction between gold and nitrogen atoms in their amino groups. Subsequently, a luminol-capped AuNP-modified electrode was fabricated by the immobilization of AuNPs on a gold electrode by virtue of cysteine molecules and then immersion in a luminol solution. The modified electrode was characterized by cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy. The as-prepared modified electrode exhibited an electrochemiluminescence (ECL) response in alkaline aqueous solution under a double-step potential. H2O2 was found to enhance the ECL. On this basis, an ECL sensor for the detection of H2O2 was developed. The method is simple, fast, and reagent free. It is applicable to the determination of H2O2 in the range of 3x10(-7)-1x10(-3) mol L(-1) with a detection limit of 1x10(-7) mol L(-1) (S/N=3).     

TiO2/Nafion film based electrochemiluminescence for detection of dissolved oxygen

TiO₂ nanocrystals had been modified on the surface of the glassy carbon electrode (GCE) with the help of Nafion. The electrochemiluminescence (ECL) behavior of the TiO₂/Nafion GCE in aqueous solution was investigated. A possible mechanism about the ECL of TiO₂ had also been proposed. The ECL intensity was linear with the dissolved oxygen concentration in the range of 0.30–10.00 mg/L with a detection limit of 0.12 mg/L. The developed method can be applied to detect the dissolved oxygen concentration or biochemical oxygen demand (BOD).     

The enhanced electrochemiluminescence of luminol on the nickel phthalocyanine modified electrode

A glassy carbon electrode (GCE) modified with nickel(II) tetrasulfophthalocyanine (NiTSPc) and Nafion was used for the investigation of the catalytic oxidation of luminol. The modified electrode was found to much more effectively improve the emission of electrochemiluminescence(ECL) of luminol in a solution containing hydrogen peroxide. The enhanced ECL signal corresponded to the catalytic oxidation of both luminol and H(2)O(2) by NiTSPc. Attached Ni(II) on GCE was oxidised to Ni(III) and then used as the catalyst for the chemiluminescence of luminol. The enhanced stability of the ECL signal with Nafion would mainly result from the prevention of the dissolution of NiTSPc and the adsorption of the oxidation product of luminol on the electrode surface. The proposed method enables a detection limit for luminal of 6.0 x 10(-8) mol L(-1) to be achieved in the presence of H(2)O(2) in the neutral solution. The enhanced ECL intensity had a linear relationship with the concentration of luminol in the range of 1.0 x 10(-7)-8.0 x 10(-6) mol L(-1).     

Enhanced electrochemiluminescence employed for the selective detection of methyl parathion based on a zirconia nanoparticle film modified electrode

A simple, rapid and sensitive electrochemiluminescence (ECL) sensor was proposed for direct measurements of methyl parathion (MP) based on the strong affinity of a nano zirconia particles (ZrO(2) NPs) modified film on the electrode to the phosphoric group. ZrO(2) NPs, which could provide a larger absorption area to immobilize organophosphorus, was firstly modified on the glassy carbon electrode surface to prepare the proposed ECL sensor (ZrO(2)/GC). Subsequently, the ZrO(2)/GC electrode was scanned from -0.8 to +0.6 V to obtain the background signal at 0.44 V in a luminol/KCl solution. Then, a certain concentration of MP was added to an aqueous solution for 240 s, which was absorbed onto the ZrO(2)/GC electrode surface. Moreover, the MP absorbed on the surface of the ZrO(2)/GC electrode enhanced the ECL signal of luminol in the luminol/KCl solution, which increased with the concentration of MP. As a result, a novel ECL sensor was obtained in a luminol/KCl solution. The MP was determined in the range of from 3.8 × 10(-11) to 3.8 × 10(-6) mol L(-1), with a low detection limit of 1.27 × 10(-11) mol L(-1) (S/N = 3). The proposed ECL sensor performance for MP detection will open a new field in the application of rapid and screen detection of ultra-trace amounts of organ phosphorus pesticides (OPs) of vegetables used in farm markets.     

Electrochemiluminescence detection of dichlorvos pesticide in luminol-CTAB medium

A simple, novel electrochemiluminescence (ECL) method for the detection of dichlorvos pesticide (DDVP) with high sensitivity was discovered. Detection was carried out in a static ECL system, in which a glassy carbon electrode was selected as the working electrode. ECL parameters, including the concentrations of cetyrltrimethylammonium bromide and luminol, the solution pH, and the scan rate of the applied potential, were optimized. Under these optimal conditions, the linear response of ECL-emission versus DDVP concentration was valid in the range 5-8000 ng/L (r(2)=0.9982) with a relative standard deviation of 4.3% at 2000 ng/L (n=10), yielding a detection limit (S/N=3) of 0.42 ng/L. The ECL emission was caused by a radical reaction process, in which the dissolved oxygen in the luminol solution reacted with the DDVP and generated free radicals. The free radicals reacted with the luminol anion and yielded the luminol radical. The approach presented was successfully applied to the determination of DDVP residues in vegetable samples.     

铂电极在碱性含氧溶液中的预还原处理对鲁米诺电 致化学发光的影响

研究了铂电极的不同预极化处理过程对碱性鲁米诺阳极电致化学发光(ECL)和阳极极化曲线的影响,发现在碱性含氧溶液中预还原处理的铂电极可增强0.22V(vs.SCE)处发光峰强度,且催化产生1.07V(vs.SCE)附近氧气析出过程并伴随产生明显的ECL发光峰;在酸性溶液中预处理电极可抑制这些活性。给出了催化氧气析出的可能作用机理：在碱性溶液中溶解氧还原生成了吸附在铂电极表面的(OH^-)~a~d~s,从而回忆了氧气的析出过程。同时给出了在碱性含氧溶液中预还原的铂电极上两个可能的ECL反应通道：(1)在0.22V鲁米诺阴离子氧化为鲁米诺自由基,然后与溶解氧反应而发光;(2)1.07V处析出的新鲜氧与鲁米诺阴离子反应而发光。     

Enhanced electrochemiluminescence from luminol at multi-walled carbon nanotubes decorated with palladium nanoparticles: a novel route for the fabrication of an oxygen sensor and a glucose biosensor

Incorporation of palladium nanoparticles on the surface of multi-walled carbon nanotubes and modification of glassy carbon electrode with the prepared nano-hybrid material led to the fabrication of a novel electrode. The modified electrode showed attractive electrocatalytic activity and sensitizing effect on luminol-O(2) and luminol-H(2)O(2) electrochemiluminescence (ECL) reactions at neutral media. The sensitized luminol-O(2) and luminol-H(2)O(2) reactions were successfully applied for the ECL determination of dissolved O(2) and glucose, respectively. Under the optimal conditions for luminol-O(2) system, the ECL signal intensity of luminol was linear with the concentration of dissolved oxygen in the range between 0.08 and 0.94 mM (r=0.9996) and for luminol-H(2)O(2) system, the ECL signal intensity of luminol was linear with the concentration of glucose in the range between 0.1 and 1000 μM (r=0.9998). The limits of detection (S/N=3) for dissolved oxygen and glucose were 0.02 mM and 54 nM, respectively. The relative standard deviations (RSD) for repetitive measurements of 0.50 mM oxygen (n=10) and 10 μM glucose (n=30) were 3.5% and 0.3%, respectively. Also, under the optimal conditions for luminol-H(2)O(2) system, the ECL signal intensity of luminol was linear with the concentration of H(2)O(2) in the range between 1 nM and 0.45 mM (r=0.9997). The limit of detection (S/N=3) for H(2)O(2) detection was 0.5 nM and the relative standard deviation for repetitive measurements of 10 μM H(2)O(2) (n=10) was 0.8%.     

电化学发光淬灭法测定SOD

在硼酸缓冲溶液（pH6．7）中性介质中,O2和H2O2均对鲁米诺的电化学发光（ECL）有敏化作用,而超氧化物歧化酶（SOD）对此敏化的电化学发光具有淬灭作用,SOD的浓度与两种发光体系的ECL光强成线性关系,可用于SOD的测定,为SOD的测定提供了一种灵敏、可靠的测定方法。