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1.
The coupling of Ru(bpy)32+ based electrochemiluminescence (ECL) detection with capillary electrophoresis (CE) was developed for the simultaneous determination of the two major active ingredients (atropine and scopolamine) in Flos daturae. Parameters related to the separation and detection were discussed and optimized. It was proved that 20 mM phosphate buffer at pH 8.48 could achieve the most favorable resolution, and the high sensitivity of detection was obtained by maintaining the detection potential at 1.2 V. Under the optimized conditions: ECL detection at 1.2 V, 20 mM phosphate buffer at pH 8.48, 5 mM Ru(bpy)32+ and 50 mM phosphate buffer at pH 7.48 in the detection reservoir, detection limits of 5 × 10−8 mol/l for atropine and 1 × 10−6 mol/l for scopolamine were obtained. Relative standard derivations of the ECL intensity and the migration time were 5.16 and 0.71% for atropine and 5.07 and 1.22% for scopolamine, respectively. Developed method was successfully applied to determine the amounts of both alkaloids in Flos daturae. A baseline separation for atropine and scopolamine was achieved within 11 min.  相似文献   

2.
In this paper the strong electrochemiluminescence (ECL) nanoparticles have been prepared based on the anionic polyelectrolyte sodium polyacrylate (PAA)-ECL enhancement for Ru(bpy)32+, which were loaded by the carrier of SiO2 nanoparticle. There were two kinds of Ru(bpy)32+ for the as-prepared nanoparticles, the doped one and the exchanged one. The former was loaded inside the ECL nanoparticles by doping, in a form of ion-pair macromolecules PAA–Ru(bpy)32+. The corresponding ECL was enhanced about 2 times owing to the doping increase of Ru(bpy)32+. The latter was loaded on the PAA-doped Nafion membrane by ion exchange. The corresponding ECL was enhanced about 3 times owing to the ion-exchanging increase of Ru(bpy)32+. At the same time, ECL intensity of the doped-inside Ru(bpy)32+ was further enhanced 13 times because polyelectrolyte PAA in the doped membrane could obviously enhance electron transfer between the doped Ru(bpy)32+ and the working electrode. Furthermore, based on hydrophobic regions of the doped membrane antibody labeling could be easily realized by the as-prepared nanoparticles and then a high sensitive ECL immunoassay for HBsAg was developed. The linear range was between 1.0 and 100 pg mL−1 (R2 = 0.9912). The detection limit could be as low as 0.11 pg mL−1 (signal-to-noise ratio = 3).  相似文献   

3.
In this paper, a novel electrochemiluminescence (ECL) sensor was constructed to determine herring sperm (HS) double-stranded (ds) DNA. Tetramethoxysilane and dimethyldimethoxysilane were selected as co-precursors to form an organically modified silicate (ORMOSIL) film for the immobilization of multiwall carbon nanotubes (MWNTs) wrapped by poly(p-styrenesulfonate) (PSS), and then Tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)32+) was successfully immobilized on a glassy carbon electrode via ion-association. PSS was employed to increase the conductivity of the ORMOSIL film and disperse the cut MWNTs, which were cut and shortened in a mixture of concentrated sulfuric and nitric acids, in the film. It was found that MWNTs could adsorb Ru(bpy)32+ and acted as conducting pathways to connect Ru(bpy)32+ sites to the electrode. MWNTs also played a key role as materials for the mechanical and thermal properties. The ECL performance of this modified electrode was evaluated in a flow injection analysis (FIA) system, and the detection limit (S/N = 3) for HS ds-DNA was 2.0 × 10−7 g mL−1 with a linear range from 1.34 × 10−6 to 6.67 × 10−4 g mL−1 (R2 = 0.9876). In addition, the ECL sensor presented excellent characteristics in terms of stability, reproducibility and application life.  相似文献   

4.
In this work, a stable electrogenerated chemiluminescence (ECL) detector was developed. The detector was prepared by packing cation-exchanged resin particles in a glass tube, followed by inserting Pt wires (working electrode) in this tube and sealing. The leakage of Ru(bpy)32+ can be compensated by adding a small amount of Ru(bpy)32+ into solution phase. Coupled with high-performance liquid chromatography separation, the detector has been used for determination of itopride hydrochloride in human serum. Under the optimal conditions, the ECL intensity has a linear relationship with the concentration of itopride hydrochloride in the range of 1.0 × 10−8 g mL−1 to 1.0 × 10−6 g mL−1 and the detection limit was 3 × 10−9 g mL−1 (S/N = 3). The as-prepared ECL detector displayed good sensitivity and stability.  相似文献   

5.
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   

6.
Electrochemical behavior and electrogenerated chemiluminescence (ECL) of tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)32+) immobilized in poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate)-poly(vinyl alcohol) (PEDOT/PSS-PVA) composite films via ion-exchange have been investigated with tripropylamine (TPA) as the co-reactant at a glassy carbon electrode. The immobilized Ru(bpy)32+ performed a surface-controlled electrode reaction. The Ru(bpy)32+ modified electrode showed a fast ECL response to TPA, and was used for the ECL detection of TPA with high sensitivity. The ECL intensity was linearly related to concentrations of TPA over the range from 0.50 μmol L−1 to 0.80 mmol L−1, and the detection limit was 0.10 μmol L−1 (S/N = 3). The as-prepared electrode exhibited good precision and long-term stability for TPA determination.  相似文献   

7.
Adrenaline was found to inhibit strongly the electrochemiluminescence (ECL) from the Ru(bpy)32+/tripropylamine system when a working Pt electrode was maintained at 1.05 V (versus Ag/AgCl) in pH 8.0 phosphate buffer. On this basis, a flow injection (FI) procedure with inhibited electrochemiluminescence detection has been developed for determination of adrenaline. The method exhibited a good reproducibility, sensitivity, and stability with a detection limit (signal-to-noise ratio = 3) of 7.0×10−9 mol l−1 and dynamic concentration range of 2×10−8 to 1×10−4 mol l−1. The relative standard deviation was 2.2% for 1.0×10−6 mol l−1 adrenaline (n=11). The method was successfully applied to the determination of adrenaline in pharmaceutical samples. Moreover, ECL emission spectra, UV-Vis absorption spectra and cyclic voltammograms of Ru(bpy)32+/tripropylamine/adrenaline were studied. The inhibition mechanism has been proposed as the interaction of electrogenerated Ru(bpy)32+* and the o-benzoquinone derivatives, adrenochrome and adrenalinequinone, at the electrode surface.  相似文献   

8.
A new electrochemiluminescent (ECL) detection system equipped with an electrically controlled heating cylindrical microelectrode (HME) was developed in this paper. The cylindrical microelectrode made of platinum wire (25 μm in diameter, 6 mm in long) was used as the working electrode of the ECL detection system, the temperature of the electrode could be controlled electrically. The Ru(bpy)32+-ECL and Ru(bpy)32+-C2O42−-ECL systems were used to evaluate this ECL detection system. The detection limit for oxalate was found to be 3.0 × 10−4 mol/L when Te (temperature of the HME) was 22 °C, and found to be 3.0 × 10−6 mol/L at 80 °C, which indicates that the detection limit can be improved greatly at higher Te, based on which, it is possible to establish a more sensitive method for measurement of ECL by using a heated microelectrode.  相似文献   

9.
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   

10.
Here, we describe a new approach for electrochemiluminescence (ECL) assay with Ru(bpy)32+-encapsulated silica nanoparticle (SiO2@Ru) as labels. A water-in-oil (W/O) microemulsion method was employed for one-pot synthesis of SiO2@Ru nanoparticles. The as-synthesized SiO2@Ru nanoparticles have a narrow size distribution, which allows reproducible loading of Ru(bpy)32+ inside the silica shell and of α-fetoprotein antibody (anti-AFP), a model antibody, on the silica surface with glutaraldehyde as linkage. The silica shell effectively prevents leakage of Ru(bpy)32+ into the aqueous solution due to strong electrostatic interaction between the positively charged Ru(bpy)32+ and the negatively charged surface of silica. The porous structure of silica shell allowed the ion to move easily through the pore to exchange energy/electrons with the entrapped Ru(bpy)32+. The as-synthesized SiO2@Ru can be used as a label for ultrasensitive detection of biomarkers through a sandwiched immunoassay process. The calibration range of AFP concentration was 0.05-30 ng mL−1 with linear relation from 0.05 to 20 ng mL−1 and a detection limit of 0.035 ng mL−1 at 3σ. The resulting immunosensors possess high sensitivity and good analytical performance.  相似文献   

11.
A novel method for immobilization of tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)3Cl2) on electrode surfaces based on the vapor-surface sol-gel deposition strategy is first demonstrated in this paper. Ru(bpy)3Cl2 immobilized sol-gel (Ru(bpy)3Cl2/sol-gel) films were characterized by UV-vis spectroscopy and field-emitted scanning electron microscopy (FE-SEM). These results showed that Ru(bpy)3Cl2 was successfully incorporated into the silica sol-gel film. It was found that many irregular Ru(bpy)3Cl2/sol-gel clusters were formed on surfaces through one deposition and thick sol-gel films were observed after further deposition. Electrochemical properties and electrochemiluminescence (ECL) behaviors of Ru(bpy)3Cl2/sol-gel films could be easily adjusted by deposition numbers and time. At last, the Ru(bpy)3Cl2/sol-gel film modified electrode was used for solid-state ECL detection of tripropylamine. The linear range was from 5.8 × 10−8 to 2.4 × 10−4 M with the detection limit of 5 nM, which was three orders of magnitude lower than that from pure Nafion-modified electrodes. The ECL sensor also exhibited high stability, and still remained 92% response after being stored in air for 35 days. This method for immobilization of Ru(bpy)3Cl2 is simple, convenient and low-cost relative to others, so it shows promising applications in solid-state ECL detection.  相似文献   

12.
Qiu B  Xue L  Wu Y  Lin Z  Guo L  Chen G 《Talanta》2011,85(1):339-344
Inhibited Ru(bpy)32+ electrochemiluminescence by inorganic oxidants is investigated. Results showed that a number of inorganic oxidants can quench the ECL of Ru(bpy)32+/tri-n-propylamine (TPrA) system, and the logarithm of the decrease in ECL intensity (ΔI) was proportional to the logarithm of analyte concentrations. Based on which, a sensitive approach for detection of these inorganic oxidants was established, e.g. the log-log plots of ΔI versus the concentration of MnO4, Cr2O72− and Fe(CN)63− are linear in the range of 1 × 10−7 to 3 × 10−4 M for MnO4 and Cr2O72−, and 1 × 10−7 to 1 × 10−4 M for Fe(CN)63−, with the limit of detection (LOD) of 8.0 × 10−8 M, 2 × 10−8 M, and 1 × 10−8 M, respectively. A series of experiments such as a comparison of the inhibitory effect of different compounds on Ru(bpy)32+/TPrA ECL, ECL emission spectra, UV-Vis absorption spectra etc. were investigated in order to discover how these inorganic analytes quench the ECL of Ru(bpy)32+/TPrA system. A mechanism based on consumption of TPrA intermediate (TPrA·) by inorganic oxidants was proposed.  相似文献   

13.
The combined flow injection (FI)-capillary electrophoresis (CE) system was further exploited by coupling to an electrogenerated chemiluminescence (ECL) detection system. A low-cost miniaturized CE system was developed on a chip platform to provide easy interface both with FI sample introduction and with ECL detection. A falling-drop interface was employed to perform FI split-flow sample introduction while achieving electrical isolation from the CE high voltage. A plexiglas reservoir at the capillary outlet served as both the reaction and detection cell for the ECL reaction, with Ru(bpy)32+ reagent continuously flowing through the cell. An optical fiber was positioned within the reservoir close to the capillary outlet for transferring the ECL emission to the PMT. The relative positions of the capillary outlet, working electrode and optical fiber as well as reagent renewal flow-rate were optimized to achieve both good sensitivity and separation efficiency under non-interrupted sampling conditions, involving large numbers of samples. An on-column joint often used in other works for isolating the ECL detection system from the CE separation voltage was not found necessary. The performance of the system was illustrated by the baseline separation of proline, valine and phenylalanine with a high throughput of 50 h−1 and plate height of 14 μm for proline under 147 V cm−1 field strength. Detection limits (3σ) were 1.2, 50 and 25 μM and peak height precisions were 1.4, 5.4 and 4.3% R.S.D. (n=9) for proline, valine and phenylalanine, respectively.  相似文献   

14.
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 pKa (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.  相似文献   

15.
Electrochemiluminescence (ECL) of ruthenium complexes has broad applications and the immobilization of Ru(bpy)32+ has received extensive attention. In comparison with Ru(bpy)32+, Ru(phen)32+ can be immobilized more easily because of its better adsorbability. In this study, immobilization of Ru(phen)32+ for ECL analysis has been demonstrated for the first time by using graphene oxide (GO) as an immobilization matrix. The immobilization of Ru(phen)32+ is achieved easily by mixing Ru(phen)32+ with GO without using any ion exchange polymer or covalent method. The strong binding of Ru(phen)32+ with GO is attributed to both the π–π stacking interaction and the electrostatic interaction. The Ru(phen)32+/GO modified electrode was characterized by using tripropylamine (TPA) as the coreactant. The linear range of TPA is from 3 × 10−7 to 3 × 10−2 mol L−1 with the detection limit of 3 × 10−7 mol L−1. The ECL sensor demonstrates outstanding long-term stability. After the storage in the ambient environment for 90 days, the ECL response remains comparable with its original signal.  相似文献   

16.
A new electrogenerated chemiluminescence biosensor was fabricated by immobilizing ECL reagent Ru(bpy)32+ and alcohol dehydrogenase in sol-gel/chitosan/poly(sodium 4-styrene sulfonate) (PSS) organically modified composite material. The component PSS was used to immobilize ECL reagent Ru(bpy)32+ by ion-exchange, while the addition of chitosan was to prevent the cracking of conventional sol-gel-derived glasses and provide biocompatible microenvironment for alcohol dehydrogenase. Such biosensor combined enzymatic selectivity with the sensitivity of ECL detection for quantification of enzyme substrate and it was much simpler than previous double-layer design. The detection limit was 9.3 × 10−6 M for alcohol (S/N = 3) with a linear range from 2.79 × 10−5 to 5.78 × 10−2 M. With ECL detection, the biosensor exhibited wide linear range, high sensitivity and good stability.  相似文献   

17.
Liu H  Yuan R  Chai Y  Mao L  Yang X  Zhuo Y  Yuan Y 《Talanta》2011,84(2):387-392
A new electrochemiluminescence (ECL) detector for capillary electrophoresis (CE) based on tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)32+) immobilized in Nafion/PTC-NH2 (an ammonolysis product of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA)) composite film was presented for the first time. The Nafion/PTC-NH2 composite film could effectively immobilize tris(2,2′-bipyridyl)ruthenium(II) via ion-exchange and electrostatic interaction. Cyclic voltammetric and ECL behavior of Nafion/PTC-NH2/Ru composite film was investigated compared to Nafion/Ru composite. The Nafion/PTC-NH2/Ru composite film exhibited good ECL stability and simple operability. Then the CE with solid-state ECL detector system was successfully used to detect sophora - a quinolizidine type - alkaloids as sophoridine (SR) and matrine (MT). The CE-ECL parameters that affected separation and detection were optimized. Under the optimized conditions, the linear range was from 2.5 × 10−8 to 2 × 10−6 mol/L for SR, 1.0 × 10−8 to 1.0 × 10−6 mol/L for MT. The detection limit (S/N = 3) was estimated to be 5 × 10−9 and 10−9 mol/L for SR and MT, respectively. It was shown that the CE coupling with solid-state ECL detector system exhibited satisfying sensitivity of analysis.  相似文献   

18.
The electrochemistry and electrochemiluminescence (ECL) of novel three-dimensional nanostructured Ru(bpy)32+/Ni(OH)2 microspheres were investigated for the first time. The negatively charged porous Ni(OH)2 microspheres composed of Ni(OH)2 nanowires were specifically designed to interact with Ru(bpy)32+. The large surface area and porous structure of Ni(OH)2 microspheres enhance loading of Ru(bpy)32+ and mass transport of the model analyte, tripropylamine (TPA). Excellent ECL performance of the presented sensor was achieved including good stability and wide linear range from 7.7 × 10−10 to 3.8 × 10−3 M with the detection limit of 2.6 × 10−10 M to TPA.  相似文献   

19.
Apurinic/apyrimidinic endonuclease 1 (APE-1), a kind of multifunctional protein widely-distributed in the body, plays an essential role in the DNA base excision repair and serves as multiple possible roles in the response of human cancer to radiotherapy and chemotherapy. In this work, an ultrasensitive solid-state electrochemiluminescence (ECL) immunosensor is designed to determine APE-1 based on the new Ru(bpy)32+/bi-arginine system. The bi-arginine (bi-Arg) is decorated on the Au nanoparticles functionalized magnetic Fe3O4/reduced graphene oxide (bi-Arg/Au@Fe3O4–rGO) according to the self-assembling and covalent cross-linking interaction to obtain the functionalized nanocomposite of bi-Arg/Au@Fe3O4–rGO. Herein, the bi-Arg/Au@Fe3O4–rGO plays not only an amplification label to enhance the ECL signal of Ru(bpy)32+ due to the coreactant of bi-Arg but also an ideal nanocarrier to load numerous secondary antibody. Based on sandwich-type immunoassay format, this proposed method offers a linear range of 1.0 fg mL−1–5.0 pg mL−1 and an estimated detection limit of 0.3 fg mL−1 for the APE-1. Moreover, the reagentless ECL immunosensor also exhibits high sensitivity, excellent selectivity and good stability, which has greatly potential development and application in clinical diagnostics, immunology and biomedical research.  相似文献   

20.
Ding SN  Xu JJ  Zhang WJ  Chen HY 《Talanta》2006,70(3):572-577
Tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)32+)-Zirconia-Nafion composite modified glassy carbon disk electrode as a solid-state electrochemiluminescence (ECL) detector is successfully applied to an electrophoretic microchip system with a wall-jet configuration. Pharmaceuticals such as tramadol, lidocaine and ofloxacin were selected to characterize the performance of this microchip capillary electrophoresis (CE)-ECL detection system. Voltammetric and ECL behaviors of immobilized Ru(bpy)32+ were investigated in lidocaine system. Influences of the separation electric field to cyclic voltammograms (CVs) of the immobilized Ru(bpy)32+ were also investigated. Tramadol, lidocaine and ofloxacin can be baseline separated without any additives. The detection limits (S/N = 3) were 2.5 × 10−5 mol L−1 for tramadol, 5.0 × 10−6 mol L−1 for lidocaine, 1.0 × 10−5 mol L−1 for ofloxacin under the sample injection of picoliters, and the linear ranges were from 5.0 × 10−5 to 2.5 × 10−3 mol L−1 for tramadol, 1.0 × 10−5 to 1.0 × 10−3 mol L−1 for lidocaine, and 1.0 × 10−5 to 2.5 × 10−3 mol L−1 for ofloxacin, respectively.  相似文献   

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