943 resultados para RUTHENIUM(II) COMPLEX
Resumo:
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.
Resumo:
Different effects of divalent metal ions on electrochemiluminescence (ECL) sensor with Ru(bPY)(3)(2+) immobilized in Eastman-AQ membrane were investigated. Mg2+,Ca2+ and Fe2+ can elevate the ECL of Ru(bpY)(3)(2+)/proline; while metal ions that underwent redox reactions on the electrode such as Mn2+ and Co2+ presented intensive quenching effects on Ru(bpy)(3)(2+) ECL. Also, the quenching effect of Mn2+ on the ECL sensor with Ru(bpY)(3)(2+) immobilized in Eastman-AQ membrane enhanced to about 30-folds compared with the case that Ru(bpy)(3)(2+) was dissolved in phosphate buffer, and the enhanced quenching effects of Mn2+ were studied.
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A new approach for fast and sensitive electrochemiluminescence (ECL) detection of narcotic drugs on a microchip after separation by micellar electrokinetic chromatography (MEKC) is presented, taking the cocaine and its hydrolysate ecgonine as the test analytes. The mixture of hydrophilic BMIMBF4 ionic liquid (IL) and sodium dodecyl sulfate (SDS) was used directly as the buffer of MEKC with less noisy baselines, lower electrophoretic current and satisfactory separation performance.
Resumo:
Spherical Ru(bpy)(3)(2+)-doped silica (RuSi) nanoparticles were prepared via a water-in-oil microemulsion approach. The electrochemical and electrochemiluminescent properties of the RuSi nanoparticles immobilized on an indium tin oxide (ITO) electrode were investigated. Further, electrochemiluminescence (ECL) of the RuSi nanoparticles with covalently coated biomacromolecules was studied. By covalent cross-linking with glutaraldehyde, gamma-(aminopropyl) triethoxysilane (APTES)-pretreated RuSi nanoparticles were coupled with different concentrations of bovine serum albumin (BSA), hemoglobin, and myoglobin, respectively.
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Fe(III), Cr(III), Fe(II), Co(II) and Ni(II) chloride complexes supported by 2,6-bis[1-(iminophenyl)ethyl]pyridine have been synthesized and characterized along with single crystal X-ray diffraction. These complexes, in combination with MAO, have been examined in butadiene polymerization. The catalytic activity and regioselectivity are strongly controlled by metal center and cocatalyst (MAO/Co ratio dependent in the case of Co(II) complex). The activity decreases in the order of Fe(III) > Co(II) > Cr(III) approximate to Ni (II) complexes, in consistent with the space around the metal center. Polybutadiene with different microstructure content, from high trans-1,4 units (88-95% for iron(III) and Cr(III)), medium trans-1,4 and cis-1,4 units (55% and 35%, respectively, for iron(II)) to high cis-1,4 units 79% for Co(II) and 97% for Ni(II) call be easily achieved by varying of the metal center.
Resumo:
Among various ECL systems, such as 9,10-diphenylanthracene, lucigenin, tris(2,2'-bipyridyl) ruthenium, peroxyoxalate, luminol, graphene, and nanocrystals, Ru(bpy)(3)(2+) ECL is one of the most widely studied ECL systems in recent years due to its broad applications in immunoassays, DNA probe assays, coreactants analysis, and aptasensors. In this review, the progress in Ru(bpy)(3)(2+) ECL has been summarized on the whole, and the future research trends have been proposed.
Resumo:
We developed a stable, sensitive electrochemiluminescence (ECL) biosensor based on the synthesis of a new sol-gel material with the ion-exchange capacity sol-gel to coimmobilize the Ru(bpy)(3)(2+) and enzyme. The partial sulfonated (3-mercaptopropyl)-trimethoxysilane sol-gel (PSSG) film acted as both an ion exchanger for the immobilization of Ru(bpy)(3)(2+) and a matrix to immobilize gold nanoparticles (AuNPs). The AuNPs/PSSG/Ru(bpy)(3)(2+) film modified electrode allowed sensitive the ECL detection of NADH as low as 1 nM. Such an ability of AuNPs/PSSG/Ru(bpy)(3)(2+) film to promote the electron transfer between Ru(bpy)(3)(2+) and the electrode suggested a new, promising biocompatible platform for the development of dehydrogenase-based ECL biosensors. With alcohol dehydrogenase (ADH) as a model, we then constructed an ethanol biosensor, which had a linear range of 5 mu M to 5.2 mM with a detection limit of 12 nM.
Resumo:
An effective electrochemiluminescence (ECL) sensor based on Nafion/poly(sodium 4-styrene sulfonate) (PSS) composite film-modified ITO electrode was developed. The Nafion/PSS/Ru composite film was characterized by atomic force microscopy, UV-vis absorbance spectroscopy and electrochemical experiments. The Nafion/PSS composite film could effectively immobilize tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)(3)(2+)) via ion-exchange and electrostatic interaction. The ECL behavior of Ru(bpy)(3)(2+) immobilized in Nafion/PSS composite film was investigated using tripropylamine (TPA) as an analyte. The detection limit (S/N = 3) for TPA at the Nafion/PSS/Ru composite-modified electrode was estimated to be 3.0 nM, which is 3 orders of magnitude lower than that obtained at the Nafion/Ru modified electrode. The Nafion/PSS/Ru composite film-modified indium tin oxide (ITO) electrode also exhibited good ECL stability. In addition, this kind of immobilization approach was simple, effective, and timesaving.
Resumo:
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 micro-structures occurs in a single process by direct mixing of aqueous solutions of [Ru(bpy)(3)]Cl-2 and K-3[Fe(CN)(6)] at room temperature. The electrostatic interactions between [Ru(bpy)(3)]Cl-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.
Resumo:
Polyethyleneimine-functionalized platinum nanoparticles (PtNPs) with excellent electrochemiluminescence (ECL) properties were synthesized and applied to the amplified analysis of biomolecules. These particles were prepared at room temperature, with hyperbranched polyethyleneimine (HBPEI) as the stabilizer. The UV/Vis absorption spectra and transmission electron microscopy images clearly confirmed the formation of monodisperse PtNPs. Such particles proved to possess high stability against salt-induced aggregation, enabling them to be employed even under high-salt conditions. Owing to the existence of many tertiary amine groups, these particles exhibited excellent ECL behavior in the presence of tris(2.2'-bipyridyl)ruthenium(II). An HBPEI-coated particle possessed an ECL activity that was at least 60 times higher than that of a tripropylamine molecule. Furthermore, these particles could be immobilized on the 3-aminopropyltriethoxysilane-treated quartz substrates to amplify the binding sites for carboxyl groups. Through this approach, PtNPs were applied to the amplified analysis of the hemin/G-quadruplex DNAzyme by using the luminol/H2O2 chemiluminescence method.
Resumo:
Herein, homogenously partial sulfonation of polystyrene (PSP) was performed. An effective electrochemiluminescence (ECL) sensor based on PSP with carbon nanotube (CNTs) composite film was developed. Cyclic voltammetry and electrochemical impendence spectroscopy were applied to characterize this composite film. The PSP was used as an immobilization matrix to entrap the ECL reagent Ru(bpy)(3)(2+) due to the electrostatic interactions between sulfonic acid groups and Ru(bpy)(3)(2+) cations. The introduction of CNTs into PSP acted not only as a conducting pathway to accelerate the electron transfer but also as a proper matrix to immobilize Ru(bpy)(3)(2+) on the electrode by hydrophobic interaction. Furthermore, the results indicated the ECL intensity produced at this composite film was over 3-fold compared with that of the pure PSP film due to the electrocatalytic activity of the CNTs. Such a sensor was verified by the sensitive determinations of 2-(dibutylamino)ethanol and tripropylamine.
Resumo:
Capillary electrophoresis with electrochemiluminescene detection was used to characterize procaine hydrolysis as a probe for butyrylcholinesterase by in vitro procaine metabolism in plasma with butyrylcholinesterase acting as bioscavenger. Procaine and its metabolite N,N-diethylethanolamine were separated at 16 kV and then detected at 1.25 V in the presence of 5.0 mM Ru(bpy)(3)(2+), with the detection limits of 2.4 x 10(-7) and 2.0 x 10(-8) mol/L (S/N=3), respectively. The Michaelis constant K-m value was 1.73 x 10(-4) mol/L and the maximum velocity V-max was 1.62 x 10(-6) mol/L/min. Acetylcholine bromide and choline chloride presented inhibition effects on the enzymatic cleavage of procaine, with the 50% inhibition concentration (IC50) of 6.24 x 10(-3) and 2.94 x 10(-4) mol/L.
Resumo:
One-step synthesis of Ru (bpy)(3) Cl-2-immobilized (bpy = 2,2'-bipyridine) silica nanoparticles (Ru-silica nanoparticles) for use in electrogenerated-chemiluminescence (ECL) detection is reported. Ru-silica nanoparticles are prepared by using the Stober method. Compared with free Ru(bpy)(3)Cl-2, Ru-silica nanoparticles are seen to exhibit a red-shift of the UV-vis absorbance peak and a longer fluorescence lifetime, which are attributed to the electrostatic interaction of Ru(bpy)(3)(2+) and silica. Because silica nanoparticles are used as immobilization matrices, the surfaces of Ru-silica nanoparticles are easily modified or functionalized via the assembly of other nanoparticles, such as Au. For ECL detection, Au-colloid-modified Ru-silica nanoparticles are immobilized on a 3-mercaptopropyl-trimethoxysilane-modified indium tin oxide electrode surface by Au-S interaction; the surface concentration of electroactive Ru(bpy)(3)Cl-2 is obviously higher than that in silica films.
Resumo:
Based on electrogenerated chemiluminescence (ECL), a novel method for fabrication of alcohol dehydrogenase (ADH) biosensor by self-assembling ADH to Ru(bpy)(3)(2+) -AuNPs aggregates (Ru-AuNPs) on indium tin oxide (ITO) electrode surface has been developed. Positively charged Ru(bpy)(3)(2+) could be immobilized stably on the electrode surface with negatively charged AuNPs in the form of aggregate via electrostatic interaction. On the other hand, AuNPs are favourable candidates for the immobilization of enzymes because amine groups and cysteine residues in the enzymes are known to bind strongly with AuNPs. Moreover, AuNPs can act as tiny conduction centers to facilitate the transfer of electrons. Such biosensor combined enzymatic selectivity with the sensitivity of ECL detection for quantification of enzyme substrate, and it displayed wide linear range, high sensitivity and good stability.
Resumo:
A family of supramolecular polymers was prepared via Cd2+-directed self-assembly polymerization of his (2,2':6',2 ''-terpyridine)-based ligand monomers, using oligofluorenes and triphenylamine as bridges under mild conditions. The polymers were fully characterized using thermogravimetric analysis, inherent viscosity, electrochemical measurements, UV-visible spectroscopy, photoluminescence (PL) and electroluminescence (EL). Polymers with oligofluorenes as spacers exhibited blue emission (434-442 nm) in dimethyl acetamide (DMAc) solution, while polymers with triphenylamine as spacer presented an emission peak at 494 nn in DMAc solution. Complexation polymerization of bis(2,2':6',2 ''-terpyridine)-based ligand monomers with cadmium(II) improved fluorescence quantum yields dramatically, and the film PL quantum yields of these polymers were about 0.38-0.54. Single-layer light-emitting diodes were fabricated with the configuration indium tin oxide (ITO)/polymer/Ca/Al; the EL showed green emission and the onset voltages of the devices were 8-11 V.