金纳米球/氮掺杂石墨烯量子点固载Ru(bpy)3^2+电致化学发光法检测邻苯二酚

利用还原法制得金纳米球(Au NPs),与氮掺杂石墨烯量子点(NG QDs)杂化后,再以壳聚糖胶黏剂并通过静电作用使Ru(bpy)3^2+负载于其表面形成复合膜,制备了一种新型的固相电致化学发光(ECL)传感器。研究发现,与单一材料相比,Au NPs和NG QDs杂化复合材料作为载体显著提高了发光试剂Ru(bpy)3^2+的ECL信号。根据环境污染物邻苯二酚对该修饰电极ECL信号较强的阻抑作用,建立了测定领苯二酚的新体系。结果表明,Au NPs/NG QDs/Ru(bpy)3^2+修饰电极的ECL信号变化值与邻苯二酚的浓度负对数在5.0 nmol/L^10μmol/L之间呈良好的线性关系,检出限为3.0 nmol/L(r=0.9992)。对5.0μmol/L的邻苯二酚进行10次重复测定,相对标准偏差为4.6%,常见的共存物质不干扰测定,表明该方法的选择性较好。采用该修饰电极成功测定了河水中的邻苯二酚含量。     

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 ...     

Novel cathodic electrochemiluminescence of tris(bipyridine) ruthenium(II) on a gold electrode in acidic solution

The novel phenomenon of cathodic electrochemiluminescence on a gold electrode in tris(bipyridine) ruthenium(II) (Ru(bpy)(3)(2+)) solution is described for the first time. A cathodic electrochemiluminescence (ECL) was found to mainly occur at 0.4-0.8 V with continuous potential scanning from 0.2-1.4 V and the ECL peak was observed around 0.68 V, which was quite different from generally reported Ru(bpy)(3)(2+) ECL. Our group speculated that Ru(bpy)(3)(2+) possibly reacts with the gold electrode in the acidic phosphate buffer solution (PBS) to generate luminescence. The possible ECL mechanism was discussed according to the presented results. Moreover, it is revealed that the Au as co-reactant in the Ru-system contributed dominantly to the whole ECL. Therefore, the reaction between Ru(bpy)(3)(2+) and the newly formed Au implied that the inert metal Au could become a promising material for ECL investigations.     

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.     

Nanoscale-enhanced Ru(bpy)3(2+) electrochemiluminescence labels and related aptamer-based biosensing system

A unique multilabeling at a single-site protocol of the Ru(bpy)(3)(2+) electrochemiluminescence (ECL) system is proposed. Nanoparticles (NPs) were used as assembly substrates to enrich ECL co-reactants of Ru(bpy)(3)(2+) to construct nanoscale-enhanced ECL labels. Two different kinds of NP substrates [including semiconductor NPs (CdTe) and noble metal NPs (gold)] capped with 2-(dimethylamino)ethanethiol (DMAET) [a tertiary amine derivative which is believed to be one of the most efficient of co-reactants of the Ru(bpy)(3)(2+) system] were synthesized through a simple one-pot synthesis method in aqueous media. Although both CdTe and gold NPs realized the enrichment of ECL co-reactants, they presented entirely different ECL performances as nanoscale ECL co-reactants of Ru(bpy)(3)(2+). The different effects of these two NPs on the ECL of Ru(bpy)(3)(2+) were studied. DMAET-capped CdTe NPs showed enormous signal amplification of Ru(bpy)(3)(2+) ECL, whereas DMAET-capped gold NPs showed a slight quenching effect of the ECL signal. DMAET-capped CdTe NPs can be considered to be excellent nanoscale ECL labels of the Ru(bpy)(3)(2+) system, as even a NP solution sample of 10(-18) M was still detectable after an electrostatic self-assembly concentration process. DMAET-capped CdTe NPs were further applied in the construction of aptamer-based biosensing system for proteins and encouraging results were obtained.     

Enhanced electrochemiluminescence sensor from tris(2,2'-bipyridyl)ruthenium(II) incorporated into MCM-41 and an ionic liquid-based carbon paste electrode

The electrochemiluminescence (ECL) of tris(2,2'-bipyridyl)ruthenium(II) [Ru(bpy)(3)(2+)] ion-exchanged in the sulfonic-functionalized MCM-41 silicas was developed with tripropylamine (TPrA) as a co-reactant in a carbon paste electrode (CPE) using a room temperature ionic liquid (IL) as a binder. The sulfonic-functionalized silicas MCM-41 were used for preparing an ECL sensor by the electrostatic interactions between Ru(bpy)(3)(2+) cations and sulfonic acid groups. We used the IL as a binder to construct the CPE (IL-CPE) to replace the traditional binder of the CPE (T-CPE)--silicone oil. The results indicated that the MCM-41-modified IL-CPE had more open structures to allow faster diffusion of Ru(bpy)(3)(2+) and that the ionic liquid also acted as a conducting bridge to connect TPrA with Ru(bpy)(3)(2+) sites immobilized in the electrode, resulting in a higher ECL intensity compared with the MCM-41-modified T-CPE. Herein, the detection limit for TPrA of the MCM-41-modified IL-CPE was 7.2 nM, which was two orders of magnitude lower than that observed at the T-CPE. When this new sensor was used in flow injection analysis (FIA), the MCM-41-modified IL-CPE ECL sensor also showed good reproducibility. Furthermore, the sensor could also be renewed easily by mechanical polishing whenever needed.     

“Signal-on” Electrogenerated Chemiluminescence Biosensing Method for the Determination of Matrix Metalloproteinase 2

A simple, selective and sensitive “signal-on” electrogenerated chemiluminescence (ECL) biosensing method was developed for matrix metalloproteinase 2 (MMP-2). Ru(bpy)₃²⁺, gold nanoparticles (AuNPs) and Nafion were modified onto glassy carbon electrode (GCE) to form Ru(bpy)₃²⁺/AuNPs/Nafion/GCE as sensitive ECL platform and then ferrocene (Fc) labeled peptide was assembled onto the modified electrode to form ECL biosensing platform. The ECL intensity increased when the ECL biosensing electrode reacted with MMP-2 because of MMP-2-induced cleavage of Fc labeled peptide. The ECL method was applied to determine MMP-2 with detection limit of 0.3 ng/mL and one-step recognition, which is promising for point-of-care test of protease.     

Electrogenerated chemiluminescence reaction of tris(2,2'-bipyridine)ruthenium(II) with 2,5-dimethylthiophene as co-reactant in aqueous solution

A novel effective co-reactant for electrogenerated chemiluminescence (ECL) of Ru(bpy)(3)(2+) has been found. Alpha-position-dialkylated thiophene derivatives such as 2,5-dimethylthiophene (DMT) could be used as a co-reactant for Ru(bpy)(3)(2+) ECL. The reaction mechanism of the Ru(bpy)(3)(2+)/DMT system was proposed on the basis of the identification of the reaction product, the relationship between the molecular structure and the chemiluminescent intensity, and the electrochemical study. The obtained reaction mechanism was similar to that of the Ru(bpy)(3)(2+)/aliphatic tertiary amine system. Based on these results, the preliminary studies of the Ru(bpy)(3)(2+) ECL detection system using DMT as a co-reactant were performed. Under the optimal ECL conditions, the plot of ECL intensity versus the concentration of Ru(bpy)(3)(2+) was linear over the concentration range 1.0x10(-8) to 1.5x10(-7) M (determination coefficient=0.9996).     

Self-quenching in the electrochemiluminescence of tris(2,2'-bipyridyl) ruthenium(ii) using metabolites of catecholamines as co-reactants

Electrochemiluminescence (ECL) of Ru(bpy)(3)(2+) using metabolites of catecholamines: homovanillic acid (HVA) and vanillylmandelic acid (VMA) as co-reactants were investigated in aqueous solution for the first time. When HVA and VMA were co-existent in the buffer solution containing Ru(bpy)(3)(2+), ECL peaks were observed at a potential corresponding to the oxidation of Ru(bpy)(3)(2+), and the ECL intensity was increased noticeably when the concentrations of HVA and VMA were at lower levels. The linear calibration range was from 8.0 × 10(-5) to 1.0 × 10(-9) M for HVA and VMA. The detection limit (S/N = 3) of HVA and VMA was 4.0 × 10(-10) M. The formation of the excited state Ru(bpy)(3)(2+*) was confirmed to result from the reaction between Ru(bpy)(3)(3+) and the intermediates of HVA or VMA radicals. Moreover, it was found that the ECL intensity was quenched significantly when the concentrations of HVA and VMA were relatively higher. The mechanism of self-quenching processes involved in the Ru(bpy)(3)(2+)-HVA and -VMA ECL systems are proposed in this study.     

Using stannous ion as an excellent inorganic ECL coreactant for tris(2,2'-bipyridyl) ruthenium(II)

It was found that stannous chloride (SnCl(2)), as a popular inorganic reducing reagent, could obviously enhance the electrochemiluminescence (ECL) of tris(2,2'-bipyridyl) ruthenium(II) (Ru(bpy)(3)(2+)) in aqueous solution. Some factors affecting the ECL reactions between Ru(bpy)(3)(2+) and Sn(2+), including pH, concentrations of coreactant, and electrode materials, were investigated by comparison with a classic ECL coreactant tripropylamine (TPA). The Ru(bpy)(3)(2+)-Sn(2+) ECL coreactant system produces stronger and more stable ECL signals, can keep its excellent ECL activity over a wider pH range and has more choices in using electrode materials than the Ru(bpy)(3)(2+)-TPA ECL coreactant system. The ECL mechanism of the Ru(bpy)(3)(2+)-Sn(2+) coreactant system was also studied in detail.     

DNA biosensor based on the electrochemiluminescence of Ru(bpy)3(2+) with DNA-binding intercalators

This paper reports a novel detection method for DNA hybridization based on the electrochemiluminescence (ECL) of Ru(bpy)(3)(2+) with a DNA-binding intercalator as a reductant of Ru(bpy)(3)(3+). Some ECL-inducible intercalators have been screened in this study using electrochemical methods combined with a chemiluminescent technique. The double-stranded DNA intercalated by doxorubicin, daunorubicin, or 4',6-diamidino-2-phenylindole (DAPI) shows a good ECL with Ru(bpy)(3)(2+) at +1.19 V (versus Ag/AgCl), while the non-intercalated single-stranded DNA does not. In order to stabilize the self-assembled DNA molecules during ECL reaction, we constructed the ECL DNA biosensor separating the ECL working electrode with an immobilized DNA probe. A gold electrode array on a plastic plate was assembled with a thru-hole array where oligonucleotide probes were immobilized in the side wall of thru-hole array. The fabricated ECL DNA biosensor was used to detect several pathogens using ECL technique. A good specificity of single point mutations for hepatitis disease was obtained by using the DAPI-intercalated Ru(bpy)(3)(2+) ECL.     

基于MCM-41负载联吡啶钌的电致化学发光传感器

利用静电吸附作用将联吡啶钌[Ru(bpy)₃²⁺]负载到巯基化MCM-41介孔二氧化硅纳米颗粒上, 通过金-巯键修饰法将负载后的MCM-41固定在金电极表面, 发展了一种基于MCM-41负载联吡啶钌的电致化学发光传感器, 并研究了其电化学及电致化学发光行为. 基于三聚氰胺与增敏剂三正丙胺氨基结构的相似性, 将负载Ru(bpy)₃²⁺的MCM-41电致化学发光传感器用于三聚氰胺的检测, 获得了良好的检测效果, 为检测三聚氰胺提供了一种快速、简便的方法. 同时, 该研究为Ru(bpy)₃²⁺在电极表面的固定化提供了新思路.     

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...     

Ultrasensitive electrochemiluminescence immunoassay for tumor marker detection using functionalized Ru-silica@nanoporous gold composite as labels

In this work, we reported a simple and sensitive sandwich-type electrochemiluminescence (ECL) immunosensor for carcinoembryonic antigen (CEA) on a gold nanoparticles (AuNPs) modified glassy carbon electrode (GCE). The Ru-silica (Ru(bpy)(3)(2+)-doped silica) capped nanoporous gold (NPG) (Ru-silica@NPG) composite was used as an excellent label with amplification techniques. The NPG was prepared with a simple dealloying strategy, by which silver was dissolved from silver/gold alloys in nitric acid. The primary antibody was immobilized on the AuNPs modified electrode through l-cysteine and glutaraldehyde, and then the antigen and the functionalized Ru-silica@NPG composite labeled secondary antibody were conjugated successively to form a sandwich-type immunocomplex through the specific interaction. The concentrations of CEA were obtained in the range from 1 pg mL(-1) to 10 ng mL(-1) with a detection limit of 0.8 pg mL(-1). The as-proposed ECL immunosensor has the advantages of high sensitivity, specificity and stability and could become a promising technique for tumor marker detection.     

Synthesis of PtNPs/AQ/Ru(bpy)3(2+) colloid and its application as a sensitive solid-state electrochemiluminescence sensor material

The facile synthesis of the novel platinum nanoparticles/Eastman AQ55D/ruthenium(II) tris(bipyridine) (PtNPs/AQ/Ru(bpy)3(2+)) colloidal material for ultrasensitive ECL solid-state sensors was reported for the first time. The cation ion-exchanger AQ was used not only to immobilize ECL active species Ru(bpy)3(2+) but also as the dispersant of PtNPs. Colloidal characterization was accomplished by transmission electron microscopy (TEM), X-ray photoelectron spectrum (XPS), and UV-vis spectroscopy. Directly coating the as-prepared colloid on the surface of a glassy carbon electrode produces an electrochemiluminescence (ECL) sensor. The electronic conductivity and electroactivity of PtNPs in composite film made the sensor exhibit faster electron transfer, higher ECL intensity of Ru(bpy)3(2+), and a shorter equilibration time than Ru(bpy)3(2+) immobilized in pure AQ film. Furthermore, it was demonstrated that the combination of PtNPs and permselective cation exchanger made the sensor exhibite excellent ECL behavior and stability and a very low limit of detection (1 x 10(-15) M) of tripropylamine with application prospects in bioanalysis. This method was very simple, effective, and low cost.     

Ultrasensitive gaseous NH3 sensor based on ionic liquid-mediated signal-on electrochemiluminescence

This work reports that ammonia (NH(3)) can be used as an efficient co-reactant for tris(2,2'-bipyridine)ruthenium(II) (Ru(bpy)(3)(2+)) electrochemiluminescence (ECL) in ionic liquids (ILs), on the basis of which a signal-on ECL sensor for directly detecting gaseous NH(3) has been developed. The NH(3) ECL sensor has a very high sensitivity, with a detection limit of 10 ppt NH(3) (at signal-to-noise ratio of 3) without any preconcentration. The high sensitivity is mainly due to the zero ECL background of Ru(bpy)(3)(2+) in the ILs, strong co-reactant ECL activity of NH(3), and high solubility of NH(3) in imidazolium-based ILs. Additionally, the ECL sensor shows an excellent selectivity against common interfering gases and a wide linear response range from 10 ppt to 10 ppm.     

Design of a Solid‐State Electrochemiluminescence Biosensor for Detection of PML/RARα Fusion Gene Using Ru(bpy)${{{2+\hfill \atop 3\hfill}}}$‐AuNPs Aggregations on Gold Electrode

A solid‐state electrochemiluminescence (ECL) biosensor based on special ferrocene‐labeled molecular beacon (Fc‐MB) for highly sensitive detection of promyelocytic leukemia/retinoic acid receptor alpha (PML/RARα) fusion gene was developed successfully using Ru(bpy)${{{2+\hfill \atop 3\hfill}}}$ /2‐(dibutylamino)ethanol (DBAE) as detecting pattern. Such a special sensor involves two main parts, an ECL substrate and an ECL intensity switch. The ECL substrate was made by modifying the complex of Ruthenium (II) tris‐(bipyridine) and Au nanoparticles (Ru(bpy)${{{2+\hfill \atop 3\hfill}}}$ ‐AuNPs) onto the Au electrode (AuE) surface. The molecular beacon probe in which the ferrocene tag could effectively quench the ECL of the Ru(bpy)${{{2+\hfill \atop 3\hfill}}}$ acted as ECL intensity switch. The molecular beacon probe was designed with special base sequence, which could hybridize with its complementary target DNA. In the absence of a target, the hairpin structure of the probe forced the ferrocene (Fc) into close proximity with the ECL substrate, thus reducing ECL intensity. Target binding allowed the Fc away from the ECL substrate and resulted in an obvious increment in ECL intensity due to the decreased Fc quenching effect. The effect of the amount of Ru(bpy)${{{2+\hfill \atop 3\hfill}}}$ and the mixing procedure of Ru(bpy)${{{2+\hfill \atop 3\hfill}}}$ and AuNPs solution on the fabrication of ECL film had been investigated. As a result, the change of ECL intensity had a direct relationship with the logarithm of PML/RARα fusion gene concentration in the range of 0.05–500 pM with a detection limit of 7 fM, and the developed biosensor possessed good molecular recognizability in human serum. Thus, the approach holds promise for the early diagnostics and prognosis monitoring of APL and other diseases.     

Solid-state electrochemiluminescence sensor through the electrodeposition of Ru(bpy)3/AuNPs/chitosan composite film onto electrode

Tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)₃²⁺) has been successfully immobilized onto electrode through the electrodeposition of Ru(bpy)₃²⁺/AuNPs/chitosan composite film. In the experiments, chitosan solution was first mixed with Au nanoparticles (AuNPs) and Ru(bpy)₃²⁺. Then, during chronopotentiometry experiments in this mixed solution, a porous 3D network structured film containing Ru(bpy)₃²⁺, AuNPs and chitosan has been electrodeposited onto cathode due to the deposition of chitosan when pH value is over its pK_a (6.3). The applied current density is crucial to the film thickness and the amount of the entrapped Ru(bpy)₃²⁺. Additionally, these doping Ru(bpy)₃²⁺ in the composite film maintained their intrinsic electrochemical and electrochemiluminescence activities. Consequently, this Ru(bpy)₃²⁺/AuNPs/chitosan modified electrode has been used in ECL to detect tripropylamine, and the detection limit was 5 × 10⁻¹⁰ M.     

Electrogenerated Chemiluminescence Sensor Based on Tris(2,2′‐bipyridine)ruthenium(II)‐Immobilized Natural Clay and Ionic Liquid

A novel electrogenerated chemiluminescence (ECL) sensor based on natural clay and ionic liquid was fabricated. Tris(2,2′‐bipyridine)ruthenium(II) (Ru(bpy)₃²⁺) was immobilized on natural clay surface through simple adsorption. An ECL sensor was prepared by mixing Ru(bpy)₃²⁺‐incorporated clay, graphite powder and an ionic liquid (1‐butyl‐3‐methylimidazolium hexafluorophosphate) as the binder. The electrochemical behavior and ECL of the immobilized Ru(bpy)₃²⁺ was investigated. It was observed that the ECL of immobilized Ru(bpy)₃²⁺ was activated by the ionic liquid. The proposed ECL sensor showed high sensitivity to tri‐n‐propylamine (TPrA) and the detection limit was found to be 20 pM. In addition, the ECL sensor displayed good stability for TPrA detection and long‐term storage stability.     

Bifunctional nanostructure of magnetic core luminescent shell and its application as solid-state electrochemiluminescence sensor material

Bifunctional nanoarchitecture has been developed by combining the magnetic iron oxide and the luminescent Ru(bpy)32+ encapsulated in silica. First, the iron oxide nanoparticles were synthesized and coated with silica, which was used to isolate the magnetic nanoparticles from the outer-shell encapsulated Ru(bpy)32+ to prevent luminescence quenching. Then onto this core an outer shell of silica containing encapsulated Ru(bpy)32+ was grown through the St?ber method. Highly luminescent Ru(bpy)32+ serves as a luminescent marker, while magnetic Fe3O4 nanoparticles allow external manipulation by a magnetic field. Since Ru(bpy)32+ is a typical electrochemiluminescence (ECL) reagent and it could still maintain such property when encapsulated in the bifunctional nanoparticle, we explored the feasibility of applying the as-prepared nanostructure to fabricating an ECL sensor; such method is simple and effective. We applied the prepared ECL sensor not only to the typical Ru(bpy)32+ co-reactant tripropylamine (TPA), but also to the practically important polyamines. Consequently, the ECL sensor shows a wide linear range, high sensitivity, and good stability.