氮掺杂石墨烯量子点/Ru(bpy)_3~(2+)体系电致化学发光法检测邻苯二酚

采用简单的方法合成了氮掺杂石墨烯量子点(NG QDs),并分别用荧光光谱仪和透射电子显微镜进行了表征。研究了NG QDs对Ru(bpy)_3~(2+)电致化学发光(ECL)体系的增敏作用。实验优化了体系pH、Ru(bpy)_3~(2+)用量、NG QDs用量以及扫速等条件。在最优条件下,根据邻苯二酚对NG QDs/Ru(bpy)_3~(2+)耦合ECL体系信号的猝灭作用,建立了测定邻苯二酚的新方法。邻苯二酚浓度(1.0×10~(-8)～1.0×10~(-5) mol/L)的对数值与ECL信号强度差之间呈线性关系,检测限低至5.0×10~(-9) mol/L,而且选择性和重现性好,实际样品检测结果令人满意。     

硫化镉量子点对三联吡啶钌电化学发光的增敏作用及用于邻苯二酚的检测

研究了CdS量子点(CdS QDs)对三联吡啶钌(Ru(bpy)_3~(2+))电致化学发光(ECL)信号的作用,发现CdS QDs对Ru(bpy)_3~(2+)的ECL信号有良好的增敏作用,基于此建立了高灵敏的CdS QDs/Ru(bpy)_3~(2+)ECL体系。探讨了该体系的ECL机理,考察了CdS QDs的浓度、缓冲溶液p H值、扫描速率等实验参数对ECL信号的影响,优化了体系的ECL条件。基于邻苯二酚对该体系ECL信号的抑制作用,建立了邻苯二酚的ECL检测方法。在1.0×10~(-8)~1.0×10~(-5)mol/L范围内,邻苯二酚的浓度与ECL信号的变化值呈良好的线性关系,检出限(S/N=3)为5.5 nmol/L,将本方法用于茶叶中邻苯二酚的检测,结果令人满意。     

免标记自增强电化学发光免疫传感器超灵敏检测河豚毒素

以Nafion固定钌联吡啶Au纳米颗粒(Ru(bpy)2+3-Au NPs)于玻碳电极(GCE),借助Au—N共价键固定河豚毒素抗体(anti-TTX),通过抗原抗体的特异性结合构建了超灵敏检测河豚毒素(TTX)的免标记自增强电化学发光(ECL)免疫传感器。当目标物TTX被特异性捕获到修饰电极表面后,可以作为Ru(bpy)2+3的共反应物增强ECL信号。与共反应物存在于溶液中或标记于二抗上相比,其优点在于发光体和共反应物之间的电子转移距离更短,可有效改善电化学发光效率,降低实验成本。最佳条件下,TTX质量浓度在0.01~1 000μg·L-1范围内与ECL信号呈良好的线性关系,检出限(LOD)为0.01μg·L-1。此免标记自增强型ECL免疫传感器显示出优异的稳定性、重现性和灵敏度,对实际样品中TTX的回收率为98.0%~104.0%,表明其具有较好的实用价值。     

一种新型电沉积二氧化硅复合膜电化学发光雷尼替丁传感器

利用电沉积方法在玻碳电极表面制备了二氧化硅-壳聚糖(CHI)-氧化石墨烯(GO)-Ru(bpy)2+3复合膜,并采用扫描电子显微镜(SEM)技术、循环伏安法(CV)、电化学阻抗法(EIS)和电化学发光法(ECL)对修饰电极的性质进行了研究。结果表明,将壳聚糖和氧化石墨烯引入二氧化硅膜可以提高该膜的电子传递速度,且固定化的Ru(bpy)2+3在该膜中保持了良好的电化学活性。复合膜中固定化的Ru(bpy)2+3呈现出稳定的电化学发光信号。盐酸雷尼替丁对该电极的电化学发光信号有增敏作用,该增敏电化学发光信号与盐酸雷尼替丁的浓度的对数值在1.0×10-9~5.0×10-6mol/L范围内呈线性关系,相关系数r为0.9908,检出限为5×10-10mol/L。     

单个Nafion@Ru和Au-Nafion@Ru纳米粒子的电化学和电化学发光碰撞行为研究

通过静电作用在Nafion和Au-Nafion纳米粒子(NPs)上负载钌联吡啶(Ru(bpy)₃²⁺)分别制得Nafion@Ru和Au-Nafion@Ru NPs.分析并比较了Au-Nafion@Ru和Nafion@Ru NPs在金超微电极(Au UME)上随机碰撞产生电流响应峰的平均峰大小、峰电量和单峰持续时间,建立了以Au-Nafion@Ru NPs为主体的电化学碰撞体系.研究结果表明,制备的Au-Nafion@Ru NPs因其特殊结构,Nafion和AuNPs的共同参与增加了NPs与Au UME的有效接触或碰撞面积,产生了更强的电化学碰撞响应信号.在Au-Nafion@Ru NPs-三正丙胺(TPrA)体系中,同时使用电流-时间曲线和电化学发光(ECL)-时间曲线监测Au-Nafion@Ru NPs碰撞Au UME产生的电化学和ECL瞬变信号,建立了单个Au-Nafion@Ru NPs-TPrA在Au UME上瞬变电化学信号与ECL信号之间的相关性.该策略为研究其他分子电化学碰撞体系提供了思路.     

基于Ru(bpy)■-三乙胺体系的电致化学发光生物传感器检测葡萄糖

联吡啶钌(Ru(bpy)■)拥有优良的电致化学发光(ECL)性能,但其较好的水溶性使其固载面临巨大问题。该文制备了Pt纳米粒子与Ru(bpy)■的复合物(Pt NPs-Ru),将其修饰于电极并进一步固载葡萄糖氧化酶(GOx)制得传感器。基于H_2O_2对Ru(bpy)■-三乙胺体系ECL信号的猝灭作用,随着葡萄糖浓度的增加,其在GOx的催化下原位产生的H_2O_2量增多,导致ECL信号逐渐减弱,从而实现葡萄糖的检测。ECL强度与葡萄糖浓度的对数在1.0×10~(-8)～5.0×10~(-5) mol/L范围内呈良好的线性关系,检出限低至5.2×10~(-9) mol/L。传感器具有好的稳定性和高的选择性。Pt NPs-Ru复合物为ECL传感器的构建提供了良好平台,为葡萄糖检测提供了新方法。     

基于Ru(bpy)■-三乙胺体系的电致化学发光生物传感器检测葡萄糖

联吡啶钌(Ru(bpy)■)拥有优良的电致化学发光(ECL)性能,但其较好的水溶性使其固载面临巨大问题。该文制备了Pt纳米粒子与Ru(bpy)■的复合物(Pt NPs-Ru),将其修饰于电极并进一步固载葡萄糖氧化酶(GOx)制得传感器。基于H2O2对Ru(bpy)■-三乙胺体系ECL信号的猝灭作用,随着葡萄糖浓度的增加,其在GOx的催化下原位产生的H2O2量增多,导致ECL信号逐渐减弱,从而实现葡萄糖的检测。ECL强度与葡萄糖浓度的对数在1.0×10-8~5.0×10-5 mol/L范围内呈良好的线性关系,检出限低至5.2×10-9 mol/L。传感器具有好的稳定性和高的选择性。Pt NPs-Ru复合物为ECL传感器的构建提供了良好平台,为葡萄糖检测提供了新方法。     

基于二氧化硅包裹三联吡啶钌的新型咖啡因电致化学发光传感器

将包裹了三(2,2'-联二吡啶)二氯化钌(Ⅱ)配合物(Ru(bpy)32+)的二氧化硅纳米粒子(Ru(bpy)32+@Si O2)通过Nafion膜修饰在玻碳电极上,并研究了咖啡因在此电极上的电化学发光行为。在单因素实验的基础上,结合响应面分析法对实验条件进行了优化,建立了一种检测咖啡因的新方法。在最佳的实验条件下,咖啡因浓度在5.0×10-3~20μmol/L范围内与其相对发光强度呈良好的线性关系(r2=0.9996),检出限(S/N=3)为1.3×10-3μmol/L。连续平行测定1μmol/L的咖啡因溶液5次,相对发光强度的RSD为3.8%。方法用于可乐样品的实际测定,回收率为93.7%~103.8%。     

三联吡啶钌复合膜修饰电极电化学发光法测定马来酸氯苯那敏

以氧化铟锡(ITO)导电玻璃为基质,研制了一种SiO2/Ppy/PSS/Ru(bpy)32+复合膜修饰电极。在pH 8.00磷酸盐缓冲溶液中,马来酸氯苯那敏(CM)在修饰电极的电化学发光强度(ECL)有强增敏作用,据此建立了一种灵敏地测定马来酸氯苯那敏的电化学发光的方法。其ECL增加程度与CM的浓度在30～100μmol.L-1之间呈线性关系。方法的检出限(3S/N)为9.0×10-2μmol.L-1。对2.0μmol.L-1马来酸氯苯那敏标准溶液连续测定11次,测定值的相对标准偏差为1.3%。方法用于维C银翘片中马来酸氯苯那敏的测定,回收率在96.5%～98.8%之间。     

硅量子点为共反应剂的联吡啶钌电致化学发光研究及对多巴胺的检测

利用水热法合成了水溶性硅量子点(SiQDs),并探究了联呲啶钌(Ru(bpy)■)在硅量子点修饰玻碳电极(SiQDs/GCE)上的电致化学发光(ECL)行为。结果表明,在中性条件下,SiQDs能够作为共反应剂明显增强Ru(bpy)■的阳极ECL信号。研究了SiQDs修饰量、缓冲溶液pH等因素对该体系ECL信号的影响规律,并对ECL机理进行了探讨。多巴胺对ECL信号具有明显的抑制作用,据此可以实现对多巴胺的灵敏检测。在1.0×10~(-8)～1.0×10~(-4) mol·L~(-1)范围内,多巴胺浓度与ECL信号的减少值呈线性变化关系,相关系数达0.993。     

基于Ru(bpy)32+/AuNPs/Nafion电化学发光传感器检测已烯雌酚

利用柠檬酸钠还原氯金酸制得金纳米粒子(AuNPs),基于AuNPs/Nafion与Ru(bpy)32+之间的静电引力,制备了Ru (bpy) 32+/AuNPs/Nafion电化学发光传感器.采用循环伏安法和电化学发光法对该传感器进行了表征,结果表明该传感器具有良好的稳定性和重现性,可实现对已烯雌酚的检测.在pH=7.0的0.1 mol/L磷酸盐缓冲溶液(PBS,含0.05 mol/L三正丙胺)中,当已烯雌酚与修饰电极作用15 min时,电化学发光强度减少值与已烯雌酚浓度的负对数在1.0×10-10～5.0×10-7 mol/L范围内呈良好的线性关系,检出限为6.0 X 10-11 mol/L.对1.0×10-8 mol/L已烯雌酚平行测定11次,相对标准偏差为2.7％.测定已烯雌酚实际样品的加标回收率在98.0％～104.5％之间.     

In situ synthesis of gold nanoparticles on porous polyacrylonitrile nanofibers for sensing applications

A simple and cost-effective method was reported to synthesize small size (6 nm) gold nanoparticles (AuNPs) on polyacrylonitrile (PAN) electrospun nanofibers (AuNPs/PAN). The formation of AuNPs is attributed to the in situ reduction of Au(III) to Au(0) by 4-(dimethylamino)benzaldehyde doped in the PAN nanofibers. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) confirmed that the AuNPs/PAN nanofibers showed good conductivity. The AuNPs/PAN nanofibers were used to immobilize tris(2,2'-bipyridyl)ruthenium(II) ions (Ru(bpy)(3)(2+)) to form an electrochemiluminescence (ECL) sensor. The AuNPs on the PAN nanofibers exhibited an excellent catalytic effect on the ECL of Ru(bpy)(3)(2+) which could be employed to detect low concentrations of phenolic compounds. The linear response range of the ECL sensor to hydroquinone is 0.55-37 μM with limit of detection of 80 nM (S/N = 3). This sensor has been successfully applied to determine the hydroquinone content in photographic developer samples. Our work provides a very simple and cost-effective method to synthesize AuNPs on polymer nanofibers which shows great potential in the field of electrocatalysis and chemo/biosensors.     

十二烷基苯磺酸钠-盐酸苯海索-Ru(bpy)2+3体系的电化学发光行为研究及应用

在十二烷基苯磺酸钠(SDBS)存在下,考察了盐酸苯海索(BH)-Ru(bpy)32+体系的电化学及其发光行为。结果表明,BH对Ru(bpy)32+体系的电化学发光具有增敏效应;在SDBS存在下,BH对Ru(bpy)32+体系电化学发光的增敏效应显著增强,发光强度提高约16倍。据此建立了一种高效、简便的BH电化学发光新方法。在最佳实验条件下,BH的浓度在4.0×10-7～1.0×10-4 mol/L范围内与相对发光强度呈线性关系(r=0.995 5),检出限(S/N=3)为1.11×10-9 mol/L;连续平行测定1.0×10-5 mol/L BH溶液10次,发光强度的RSD为3.2%。样品的回收率为96%～108%,RSD为4.3%。该方法样品前处理简单,具有较高的选择性和灵敏度,用于实际样品中BH的测定,结果满意。     

Electrogenerated chemiluminescence sensor for glutathione with Ru\left( {bpy} \right)_3^{2+ } -doped silica nanoparticles

An electrogenerated chemiluminescence (ECL) sensor for reduced glutathione was developed based on $ \mathrm{Ru}\left( {\mathrm{bpy}} \right)_3^{2+ } $ -doped silica nanoparticles-modified gold electrode (Ru-DSNPs/Au). These uniform Ru-DSNPs (about 58?+?4 nm) were prepared by a water-in-oil microemulsion method and characterized by transmission electron microscope and scanning electron microscope. With such a unique immobilization method, a considerable $ \mathrm{Ru}\left( {\mathrm{bpy}} \right)_3^{2+ } $ was immobilized three dimensionally on the electrode, which could greatly enhance the ECL response and thus result in an increased sensitivity. The ECL analytical performances of this sensor for reduced glutathione based on the quenched ECL emission of $ \mathrm{Ru}\left( {\mathrm{bpy}} \right)_3^{2+ } $ have been investigated in detail. Under the optimum condition, the ECL intensity was linear with the reduced glutathione concentration in the range of 1.0?×?10^?9 to 1.0?×?10^?4?mol?L^?1 (R?=?0.9971). This method has been successfully applied for the determination of reduced glutathione in serum samples with satisfactory results. The as-prepared ECL sensor for the determination of reduced glutathione displayed good sensitivity and stability.     

Ultrasensitive Eletrogenerated Chemiluminescence Immunoassay by Magnetic Nanobead Amplification

An ultrasensitive electrogenerated chemiluminescence (ECL) immunoassay was proposed by using magnetic nanobeads (MNBs) as the carrier of ECL labels for ECL emission amplification. Carcinoembryonic antigen (CEA) and MNBs were initially immobilized on a platform in 1 : 1 molar ratio via sandwich immunoreaction. Subsequently, the MNBs were released from the platform and labeled with Ru(bpy)₃²⁺ species. After the MNBs with Ru(bpy)₃²⁺ were immobilized on an Au electrode, ECL of the Ru(bpy)₃²⁺ was measured for CEA determination. A linear relation between the ECL intensity and CEA concentration was obtained in a range of 1×10^?14 to 3×10^?13 mol/L (2.0 to 60 pg/mL) with a limit of detection of 8.0×10^?15 mol/L (1.6 pg/mL).     

Solid-state electrochemiluminescence protein biosensor with aptamer substitution strategy

One solid-state electrochemiluminescence(ECL) protein biosensor based on the competing reaction and substitute reaction between protein-to-DNA aptamer and DNA-to-DNA aptamer was proposed.Additionally,the biosensor was based on ECL photo-quenching effect of ferrocene(Fc) to tris(2,2'-bipyridyl)ruthenium(II)(Ru(bpy)32+).It was built up by modification of Au nanoparticles(AuNPs) and Ru(bpy)3 2+ on one Au electrode firstly,and then self-assembly of one special double-stranded DNA(dsDNA) onto the electrode.This ...     

基于DNA电化学发光传感器研究金纳米颗粒对量子点的电化学发光影响

纳米金颗粒具有高的消光系数和良好的表面等离子体共振特性, 其等离子体共振特性受纳米金颗粒的尺寸和周围环境等因素的影响. 本文基于半导体纳米晶电化学发光信号对金纳米颗粒的距离依赖性制备了DNA电化学发光传感器. 首先利用循环伏安法(CV)在玻碳电极(GCE)表面原位沉积金纳米颗粒(AuNPs), 巯基丙酸包裹的CdS量子点(QDs)与氨基修饰的双链DNA (dsDNA)通过酰胺键缩合, 形成量子点修饰的双链DNA(QDs-dsDNA). 最后将QDs-dsDNA 通过dsDNA 另一端的巯基组装到纳米金表面, 得到CdS QDs-DNA/AuNPs/GCE电化学发光传感器. 在优化电极表面QDs-dsDNA密度、金纳米颗粒沉积方法等实验条件的基础上, 对不同传感器的表面性质进行了表征, 如形貌和电化学阻抗等. 进一步通过控制纳米金和CdS QDs之间的DNA研究了纳米金对CdS QDs发光信号的影响作用. 结果显示DNA链的长度和类型对发光信号有着重要的影响. 最后将此传感器用于环境污染物的DNA损伤检测, 显示出很好的灵敏响应.     

流动体系中维生素B~1的电致化学发光研究

在0.1mol/LNaOH水溶液中(pH12.6),维生素B~1的水解产物在玻碳电极上于+0.88V(vs.Ag/AgCl,下同)处被氧化,其氧化产物在+1.20V处与被氧化的Ru(bpy)~3^2^+反应,生成激发态的Ru(bpy)~3^2^+^*而发光,发光波长为609nm,研究结果表明水溶液的pH值影响了维生素B~1的水解速率,从而引起发光强度的明显差异。     

Determination of Amino Acids by Ru(bpy)_3~(2+) Cathodic Electrochemiluminescence with High Sensitivity

The unique cathodic electrochemiluminescence(ECL) emission of Ru(bpy)32+(bpy=2,2′-bipyridine) was observed via Nafion film at Au electrode[Au/Nafion/Ru(bpy)32+] at about 0.20 V(vs. Ag/AgCl) and applied to the determination of several amino acids without prior derivatization with high sensitivity. The cathodic electrochemilumi-nescence(ECL) exhibits the detection limits and linear ranges of several amino acids comparable to or better than those of capillary electrophoresis with conventional ECL detection method(at 1.10—1.20 V vs. Ag/AgCl) based on precolumn derivatization. The results suggest that the cathodic ECL is promising for the detection of amino acids in bioanalysis.