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1.
A novel electrogenerated chemiluminescence (ECL) sensor based on Ru(bpy)32+‐doped titania (RuDT) nanoparticles dispersed in a perfluorosulfonated ionomer (Nafion) on a glassy carbon electrode (GCE) was developed in this paper. The electroactive component‐Ru(bpy)32+ was entrapped within the titania nanoparticles by the inverse microemulsion polymerization process that produced spherical sensors in the size region of 38±3 nm. The RuDT nanoparticles were characterized by electrochemical, transmission electron and scanning microscopy technology. The Ru(bpy)32+ encapsulation interior of the titania nanoparticles maintains its ECL efficiency and also reduces Ru(bpy)32+ leaching from the titania matrix when immersed in water due to the electrostatic interaction. This is the first attempt to prepare the RuDT nanoparticles and extend the application of electroactive component‐doped nanoparticles into the field of ECL. Since a large amount of Ru(bpy)32+ was immobilized three‐dimensionally on the electrode, the Ru(bpy)32+ ECL signal could be enhanced greatly, which finally resulted in the increased sensitivity. The ECL analytical performance of this ECL sensor for tripropylamine (TPA) was investigated in detail. This sensor shows a detection limit of 1 nmol/L for TPA. Furthermore, the present ECL sensor displays outstanding long‐term stability.  相似文献   

2.
Different effects of divalent metal ions on electrochemiluminescence (ECL) sensor with Ru(bpy)32+ immobilized in Eastman‐AQ membrane were investigated. Mg2+, Ca2+ and Fe2+ can elevate the ECL of Ru(bpy)32+/proline; while metal ions that underwent redox reactions on the electrode such as Mn2+ and Co2+ presented intensive quenching effects on Ru(bpy)32+ ECL. Also, the quenching effect of Mn2+ on the ECL sensor with Ru(bpy)32+ immobilized in Eastman‐AQ membrane enhanced to about 30‐folds compared with the case that Ru(bpy)32+ was dissolved in phosphate buffer, and the enhanced quenching effects of Mn2+ were studied.  相似文献   

3.
In this study, a novel electrochemiluminescence (ECL) sensor for highly sensitive and selective detection of Pb(II) was developed based on Ru(bpy)32+ encapsulated UiO66 metal‐organic‐framework (Ru(bpy)32+?UiO66 MOF) and ?NH2 group functionalized silica (NH2?SiO2). The NH2?SiO2 with large surface area provided an excellent platform for the ECL sensor. As numerous exposed carboxyl groups were present on UiO66 backbone, the Ru(bpy)32+?UiO66 could be steadily immobilized to NH2?SiO2 by forming amide bonds. Meanwhile, the introduced UiO66 MOF which used for the encapsulation of Ru(bpy)32+, significantly enhanced the ECL efficiency of the proposed sensor, as it possessed a large specific surface area and porosity for the loading of Ru(bpy)32+. Moreover, a high quenching effect on ECL intensity was obtained in the presence of Pb(II) in the electrolyte. Under the optimal conditions, the quenched ECL intensity showed a good linear relationship within Pb(II) concentration in the range from 1.0×10?6 to 1.0×102 μM, with a detection limit of 1.0×10?7 μM (S/N=3). The proposed sensor for Pb(II) detection was simple in operation, rapid in testing, stable in signal, and showed a good anti‐interference ability to some other metal ions. Besides, its application for detecting Pb(II) in a real sample was also investigated here. This work provides a potential platform for metal ions detection in environmental monitoring field.  相似文献   

4.
Li J  Huang M  Liu X  Wei H  Xu Y  Xu G  Wang E 《The Analyst》2007,132(7):687-691
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.  相似文献   

5.
Amine‐rich nitrogen‐doped carbon nanodots (NCNDs) have been successfully used as co‐reactant in electrochemiluminescence (ECL) processes. Primary or tertiary amino groups on NCNDs have been studied as co‐reactant sites for Ru(bpy)32+ ECL, showing their eligibility as powerful alternatives to tripropylamine (TPrA). We also report the synthesis and ECL behavior of a new covalently linked hybrid of NCNDs and Ru(bpy)32+. Notably, the NCNDs in the hybrid act both as carrier for ECL labels and as co‐reactant for ECL generation. As a result, the hybrid shows a higher ECL emission as compared to the combination of the individual components, suggesting the self‐enhancing ECL of the ruthenium complex due to an intramolecular electron transfer process.  相似文献   

6.
Electrochemiluminescence (ECL) of tris(2,2′‐bipyridine)ruthenium, Ru(bpy)32+ in the presence of various co‐reactants, such as tripropylamine (TPA), oxalate ion (C2O42?), ascorbic acid (H2A) and dehydroascorbic acid (DHA), were investigated under ultrasound irradiation. In sono‐ECL experiments, an indium‐thin‐oxide (ITO) was used as working electrode, and a titanium tipped sonic horn probe (diameter 2 mm) which operated at a frequency of 20 kHz was set in the front of the ITO electrode. Under the ultrasound irradiation, ECL signals were found to be significantly enhanced when TPA and C2O42? were used as co‐reactants, only slightly enhanced in Ru(bpy)32+/DHA system, but total quenched in Ru(bpy)32+/H2A system. The difference of Ru(bpy)32+ ECL behaviors for various co‐reactant could to be due to the different kinetics of catalytic reactions associated in ECL schemes. ECL quenching effect observed in Ru(bpy)32+/H2A system was suggested to be due to electron transfer (ET) route between the excited state *Ru(bpy)32+ and ascorbate anion HA? diffused from the bulk solution, where the diffusional HA? species served as electron donor. The effect becomes more pronounced upon sonication because the effective collision frequency between *Ru(bpy)32+ and HA? would be significantly increased by the enhanced mass transport effect of ultrasound.  相似文献   

7.
《Electroanalysis》2004,16(17):1401-1405
The immobilization of tris(2,2′‐bipyridyl)ruthenium(II), Ru(bpy)32+, at a glassy carbon electrode was achieved by entrapping the Ru(bpy)32+ in a vapor deposited titania sol‐gel membrane. The electrogenerated chemiluminescence (ECL) of the immobilized Ru(bpy)32+ was studied. The Ru(bpy)32+ modified electrode showed a fast ECL response to both oxalate and proline. The ECL intensity was linearly related to concentrations of oxalate and proline over the ranges from 20 to 700 μmol L?1 and 20 to 600 μmol L?1, respectively. The detection limits for oxalate and proline at 3σ were 5.0 μmol L?1 and 4.0 μmol L?1, respectively. This electrode possessed good precision and stability for oxalate and proline determinations. The electrogenerated chemiluminescence mechanism of proline system was discussed. This work provided a new way for the immobilization of Ru(bpy)32+ and the application of titania sol‐gel membrane in electrogenerated chemiluminescence.  相似文献   

8.
《Electroanalysis》2003,15(9):803-811
Ru(II) tris‐bipyridine based ECL sensors were produced by embedding the complex inside silica glass thin films deposited via a sol‐gel dipping procedure on K‐glass conducing substrates. Films were prepared starting from a pre‐hydrolyzed ethanolic solution of Si(OC2H5)4 and Ru(bpy)3Cl2. Transparent, crack‐free and homogeneous reddish silica layers, having a thickness of 200±20 nm, were obtained. The films, either deposited at room temperature or thermally annealed at 100, 200 and 300 °C for 30 h, were structurally and chemically characterized. Ru(bpy)3Cl2 thermal stability was previously checked by thermogravimetric analysis (TGA). The films were investigated by X‐Ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS) and UV‐vis spectroscopy. XPS in‐depth profiles revealed a homogeneous distribution of the ruthenium complex inside the silica thin layers. SIMS data suggested that the embedded Ru(bpy)3Cl2 did not react with oxygen inside the oxygen‐rich silica matrix to give Ru‐O bonds. Electrochemical and ECL characterization of the thin film electrodes were made by means of cyclic voltammetry (CV) and controlled potential step experiments. The ECL sensor showed a diffusive redox behavior of the Ru(bpy)32+/Ru(bpy)33+ system. Light emission produced from the reaction between oxalic acid and the electrogenerated Ru(bpy)33+ was larger and stable when thermally treated electrodes were used after a suitable hydration period. The 300 °C treated sample was the best performing sensor both in terms of low complex leakage and sensitivity. Calibration plots relative to oxalic acid were obtained both in stationary and in flowing solutions in the concentration range 2×10?6?3×10?4 M. A linear behavior appeared in the former case, while in the latter a slight curvature was evident as a consequence of a finite diffusion time of the analyte inside the thin film. The signal repeatability, obtained by multiple 100 μL of 10?5 M oxalic acid injections in flowing solutions, was better than 4%. The obtained detection limit (computed as three times the standard deviation of the base‐line noise) was 10?6 M as oxalic acid.  相似文献   

9.
The electrogenerated chemiluminescence (ECL) of the Ru(bpy)32+ (bpy, 2,2′-bipyridine)/tri-n-propylamine (TPrA) system can be produced at an oxidation-potential well before the oxidation of Ru(bpy)32+. Here, we describe the unique features of the low-oxidation-potential (LOP) ECL. The LOP ECL exhibited strong dependence on solution pH with the maximum emission at pH  7.7. Compared with the conventional ECL, the LOP ECL was much more significantly diminished at high pH (>10), probably due to the short lifetime of TPrA cation radical which is a crucial intermediate for the LOP emission. It was also found that the preceding deprotonation step played an important role in TPrA oxidation at neutral pH and would remarkably influence the emission intensity. As excess intermediate radicals were produced upon rapid TPrA oxidation, only 5 mM TPrA was needed to achieve the maximum LOP ECL intensity in detecting trace Ru(bpy)32+ (<1 μM) and the LOP ECL response to Ru(bpy)32+ concentration was linear. Compared with the conventional Ru(bpy)32+/TPrA ECL, the LOP ECL technique not only produces higher emission intensity at lower oxidation-potential, but also significantly reduces the amount of the coreactant.  相似文献   

10.
A highly sensitive and stable tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)32+) electrogenerated chemiluminescence (ECL) sensor was developed based on carbon nanotube (CNT) dispersed in mesoporous composite films of sol-gel titania and perfluorosulfonated ionomer (Nafion). Single-wall (SWCNT) and multi-wall carbon nanotubes (MWCNT) can be easily dispersed in the titania-Nafion composite solution. The hydrophobic CNT in the titania-Nafion composite films coated on a glassy carbon electrode certainly increased the amount of Ru(bpy)32+ immobilized in the ECL sensor by adsorption of Ru(bpy)32+ onto CNT surface, the electrocatalytic activity towards the oxidation of hydrophobic analytes, and the electronic conductivity of the composite films. Therefore, the present ECL sensor based on the CNT-titania-Nafion showed improved ECL sensitivity for tripropylamine (TPA) compared to the ECL sensors based on both titania-Nafion composite films without CNT and pure Nafion films. The present Ru(bpy)32+ ECL sensor based on the MWCNT-titania--Nafion composite gave a linear response (R2 = 0.999) for TPA concentration from 50 nM to 1.0 mM with a remarkable detection limit (S/N = 3) of 10 nM while the ECL sensors based on titania-Nafion composite without MWCNT, pure Nafion films, and MWCNT-Nafion composite gave a detection limit of 0.1 μM, 1 μM, and 50 nM, respectively. The present ECL sensor showed outstanding long-term stability (no signal loss for 4 months).  相似文献   

11.
Tris(2,2′‐bipyridine)ruthenium(II) ([Ru(bpy)3]2+) is one of the most extensively studied and used electrochemiluminescent (ECL) compounds owing to its superior properties, which include high sensitivity and stability under moderate conditions in aqueous solution. In this paper we present a simple method for the preparation of [Ru(bpy)3]2+‐containing microstructures based on electrostatic assembly. The formation of such microstructures occurs in a single process by direct mixing of aqueous solutions of [Ru(bpy)3]Cl2 and K3[Fe(CN)6] at room temperature. The electrostatic interactions between [Ru(bpy)3]2+ cations and [Fe(CN)6]3? anions cause them to assemble into the resulting microstructures. Both the molar ratio and concentration of reactants were found to have strong influences on the formation of these microstructures. Most importantly, the resulting [Ru(bpy)3]2+‐containing microstructures exhibit excellent ECL behavior and, therefore, hold great promise for solid‐state ECL detection in capillary electrophoresis (CE) or CE microchips.  相似文献   

12.
A highly sensitive reversed‐phase liquid chromatographic (HPLC) method was investigated to analyze a range of positron emission tomography (PET) radiopharmaceuticals using electrogenerated chemiluminescence (ECL) detection. ECL is based on the reaction of PET molecules with tris(2,2′‐bipyridyl)ruthenium(III) [Ru(bpy)33+], which is generated through the on‐line electro‐oxidation of Ru(bpy)32+. In 21 different radiopharmaceuticals studied, 18 compounds could be detected with detection limits (signal‐to‐noise ratio = 3) of 0.12–72 ng/mL per 20 μL injection. Sufficient reproducibility and linearity were obtained for the quantitative determination of PET molecules in pharmaceutical fluid. This method could be successfully applied to quality control tests of PET radiopharmaceuticals with ultra‐high specific radioactivity. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

13.
本文应用核酸适配体构建了一种新型的电致化学发光检测蛋白体系。两个核酸适配体结合凝血酶的两个不同位点,利用这两核酸适配体与凝血酶的高亲和力构建三明治传感体系检测凝血酶。一个核酸适配体固定在金电极上用来捕获凝血酶,另一个标记有包裹电致化学发光活性物Ru(bpy)32+的二氧化硅纳米颗粒,用来检测电致化学发光信号。此核酸适配体传感器对凝血酶具有特异识别性,电致化学发光信号与凝血酶的浓度直接相关,非特异性识别的牛血红蛋白、牛血清白蛋白不干扰测定。由于在检测的核酸适配体上标记的纳米颗粒包裹有多个发光活性物,因此大大提高了发光效率和灵敏度,此法对凝血酶的线性响应范围为2.0 fmol•L-1~2.0 pmol•L-1,检测限可达1.0 fmol•L-1。  相似文献   

14.
A novel and sensitive electrochemiluminescence (ECL) method for ethanol biosensor was developed by co‐immobilizing the enzyme and ECL reagent Ru(bpy)32+ on the poly‐(3,4‐ethylene dioxythiophene) and polystyrene sulfonate functionalized graphene (PEDOT‐PSS‐G) nanocomposite film. Positively charged Ru(bpy)32+ could be immobilized effectively on the electrode surface with the negatively charged PSS and graphene, which provided a stable ECL platform for further modification with the enzyme. Moreover, the introduction of PEDOT and graphene can be acted as a conducting pathway to accelerate the electron transfer due to the high conductivity. Such biosensor combined enzymatic selectivity with the amplification of PEDOT‐PSS‐G performed well with a wide linear range, high sensitivity and good stability. The sensing platform was successfully applied to determine the amounts of alcohol in real samples.  相似文献   

15.
A approach was successfully employed for constructing a solid‐state electrochemiluminescence (ECL) immunosensor by layer‐by‐layer self‐assembly of multiwall carbon nanotubes (MWCNTs)‐Nafion composite film, Ru(bpy)32+/nano‐Pt aggregates (Ru‐PtNPs) and Pt nanoparticles (PtNPs). The influence of Pt nanoparticles on the ECL intensity was quantitatively evaluated by calculating the electroactive surface area of different electrodes with or without PtNPs to immobilize Ru(bpy)32+. The principle of ECL detection for target α‐fetoprotein antigen (AFP) was based on the increment of resistance after immunoreaction, which led to a decrease in ECL intensity. The linear response range was 0.01–10 ng mL?1 with the detection limit of 3.3 pg mL?1. The immunosensor exhibited advantages of simple preparation and operation, high sensitivity and good selectivity.  相似文献   

16.
An electrochemiluminescence (ECL) sensor based on Ru(bpy)32+-graphene-Nafion composite film was developed. The graphene sheet was produced by chemical conversion of graphite, and was characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), and Raman spectroscopy. The introduction of conductive graphene into Nafion not only greatly facilitates the electron transfer of Ru(bpy)32+, but also dramatically improves the long-term stability of the sensor by inhibiting the migration of Ru(bpy)32+ into the electrochemically inactive hydrophobic region of Nafion. The ECL sensor gives a good linear range over 1 × 10−7 to 1 × 10−4 M with a detection limit of 50 nM towards the determination of tripropylamine (TPA), comparable to that obtained by Nafion-CNT. The ECL sensor keeps over 80% and 85% activity towards 0.1 mM TPA after being stored in air and in 0.1 M pH 7.5 phosphate buffer solution (PBS) for a month, respectively. The long-term stability of the modified electrode is better than electrodes modified with Nafion, Nafion-silica, Nafion-titania, or sol-gel films containing Ru(bpy)32+. Furthermore, the ECL sensor was successfully applied to the selective and sensitive determination of oxalate in urine samples.  相似文献   

17.
The exceptional nature of WO3?x dots has inspired widespread interest, but it is still a significant challenge to synthesize high‐quality WO3?x dots without using unstable reactants, expensive equipment, and complex synthetic processes. Herein, the synthesis of ligand‐free WO3?x dots is reported that are highly dispersible and rich in oxygen vacancies by a simple but straightforward exfoliation of bulk WS2 and a mild follow‐up chemical conversion. Surprisingly, the WO3?x dots emerged as co‐reactants for the electrochemiluminescence (ECL) of Ru(bpy)32+ with a comparable ECL efficiency to the well‐known Ru(bpy)32+/tripropylamine (TPrA) system. Moreover, compared to TPrA, whose toxicity remains a critical issue of concern, the WO3?x dots were ca. 300‐fold less toxic. The potency of WO3?x dots was further explored in the detection of circulating tumor cells (CTCs) with the most competitive limit of detection so far.  相似文献   

18.
Factors affecting tris(2,2′‐bipyridyl) ruthenium(II) (Ru(bpy)32+)/tertiary amine electrochemiluminescence (ECL) were investigated in the present work with several tertiary amines as coreactants. Some new phenomena different to those of traditional Ru(bpy)32+/tripropylamine were observed, such as the different responses of different coreactants to the hydrophobic nature of the working electrode and the ECL emission of triethanolamine at 0.85 V. The pKa value (acid dissociation constant) for the deprotonation of tertiary amine group in the coreactant molecules and solubility of coreactants affect the ECL profiles vs. electrolyte pH. Moreover, the solubility of coreactants is also related to the ECL response to the addition of surfactants and electrode hydrophobic nature. Investigation of the effects of molecular structures indicated that molecules restricting the formation of the trigonal planar structure of the active radical in the electrooxidation procedure resulted in low ECL emission. The behaviors of hydroxyl and carboxylic group as substituents of α‐carbon are also totally different to the traditional opinions about the ECL from Ru(bpy)32+/tertiary amines.  相似文献   

19.
Electrochemiluminescence (ECL) and electrochemistry are reported for a heterometallic soft salt, [Ru(dtbubpy)3][Ir(ppy)2(CN)2]2 ( [Ir][Ru][Ir] ), consisting of a 2:1 ratio of complementary charged Ru and Ir complexes possessing two different emission colors. The [Ru]2+ and [Ir]? moieties in the [Ir][Ru][Ir] greatly reduce the energy required to produce ECL. Though ECL intensity in the annihilation path was enhanced 18× relative to that of [Ru(bpy)3]2+, ECL in the co‐reactant path with tri‐n‐propylamine was enhanced a further 4×. Spooling spectroscopy gives insight into ECL mechanisms: the unique light emission at 634 nm is due to the [Ru]2+* excited state and no [Ir]?* was generated in either route. Overall, the soft salt system is anticipated to be attractive and suitable for the development of efficient and low‐energy‐cost ECL detection systems.  相似文献   

20.
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   

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