Electrogenerated Chemiluminescent Research Articles

Electrogenerated chemiluminescent behavior of MCLA at an indium-tin-oxide electrode

In this paper, the electrogenerated chemiluminescence (ECL) behavior of 6-(4-methoxyphenyl)-2-methylimidazo[1,2-a]pyrazin-3(7H)-one (MCLA) at an indium-tin-oxide (ITO) electrode in phosphate buffer solution has been investigated when linear sweep voltammetry was applied. The optimum chemical conditions and electrochemical parameters for this ECL system have been investigated in detail. Under the optimum conditions, it was found that the ECL intensity was linear with the concentration of MCLA in the range of 6.0 × 10 −7 to 1.0 × 10 −5 mol/L, and its detection limit for MCLA was 2.0 × 10 −7 mol/L. The possible mechanism for ECL of MCLA at the ITO electrode was also discussion. Furthermore, it was found that some sophora flavescens, such as matrine and oxymatrine, might enhance the ECL intensity of MCLA. Therefore, it is possible to develop a new ECL method for determination of matrine and oxymatrine.

Electrochemical and surface characterization of platinum silicide electrodes and their use as stable platforms for electrogenerated chemiluminescence assays

Electrochemical methods, including cyclic voltammetry and scanning electrochemical microscopy, as well as surface techniques, including conductive atomic force microscopy (AFM) and X-ray photoelectron spectroscopy, were utilized to evaluate and characterize the extent of an oxide layer on platinum silicide (PtSi) surfaces that were pretreated by a variety of approaches; piranha solution (1:4 H2O2+H2SO4), hydrofluoric acid (HF), chemical reduction in NaBH4 and after mechanically polishing the surface. Electrochemical methods showed that in the presence of an oxide layer, the rate of electron transfer depended upon the charge of the redox couple: the more negative the charge, the slower is the rate of electron transfer. Additionally, the current levels observed in the presence of an extensive oxide layer were considerably lower than those observed after the oxide layer was removed either with HF acid or by mechanically polishing. Surface analysis and depth profiles obtained using Auger electron spectroscopy demonstrated that PtSi surfaces pretreated with piranha contained the largest amounts of surface oxides. AFM topographic scans along with localized surface conductivity showed that in the presence of this oxide layer, electron transfer occurred at nanoscale domains located between the PtSi grains with the rest of the surface, which most likely contains an oxide layer, being non-conductive. The surface oxide layer was used to attach the electrogenerated chemiluminescent (ECL) label, Ru(bpy)32+ covalently, either directly or via single-stranded DNA. Emission during oxidation in the presence of the co-reactant tri-n-propylamine was observed, illustrating the possible use of PtSi as a platform for ECL-based bioassays.

A two-channel microfluidic sensor that uses anodic electrogenerated chemiluminescence as a photonic reporter of cathodic redox reactions.

This paper describes a new approach for sensing electrochemically active substrates in microfluidic systems. This two-electrode sensor relies on electrochemical detection at one electrode and electrogenerated chemiluminescent (ECL) reporting at the other. Each microfabricated indium tin oxide electrode is located in a separate microfluidic channel, but the channels are connected downstream of the electrodes to maintain a complete electrical circuit. Because of laminar flow, there is no bulk mixing of the fluids in the detecting and reporting channels. This approach allows the ECL reaction to be physically and chemically decoupled from the sensing channel of the device, which greatly expands the number of analytes that can be detected. However, because the cathode and anode are connected, electron-transfer processes occurring at the sensing electrode are electrically coupled to the ECL reaction. Charge balance permits the ECL light output to be quantitatively correlated to electrochemical reductions at the cathode. The system is used to detect Fe(CN)6(3-), Ru(NH3)6(3+), and benzyl viologen and report their presence via Ru(bpy)3(2+) (bpy = bipyridine) luminescence. Each different redox target initiates ECL at a unique potential bias related to its standard redox potential. The influence of the concentrations of Ru(bpy)3(2+) and the target analytes is discussed.

Electrochemical sensing in microfluidic systems using electrogenerated chemiluminescence as a photonic reporter of redox reactions.

This paper describes a microfluidics-based sensing system that relies on electrochemical detection and electrogenerated chemiluminescent (ECL) reporting. The important result is that the ECL reporting reaction is chemically decoupled from the electrochemical sensing reaction. That is, the electrochemical sensing reaction does not participate directly in the ECL process, but because electrochemical cells require charge balance, the sensing and ECL reactions are electrically coupled. This provides a convenient and sensitive means for direct photonic readout of electrochemical reactions that do not directly participate in an ECL reaction and thus broadens the spectrum of redox compounds that can be detected by ECL. The approach can be implemented in either a two-electrode or bipolar (single-electrode) configuration. By manipulating the placement and dimensions of the conductors, the photonic response can be enhanced. The system is used to electrochemically detect benzyl viologen present in solution and report its presence via Ru(bpy)(3)(2+) (bpy = 2,2'-bipyridine) luminescence.

A NEW ELECTROGENERATED CHEMILUMINESCENCE DERIVATIZATION REAGENT, 3-(DIETHYLAMINO) PROPIONIC ACID FOR ALCOHOL IN HPLC USING TRIS (2,2′-BIPYRIDINE)RUTHENIUM(II)

Recently, the electrogenerated chemiluminescent (ECL) system, using tris(2,2′-bipyridine)ruthenium(II) [Ru(bpy)3 2+] has become a powerful tool for the determination of compounds containing tertiar...

Electrogenerated chemiluminescence of lucigenin enhanced by the modifications of electrodes with self-assembled monolayers and of solutions with surfactants

Electrogenerated chemiluminescence (ECL) of lucigenin (Luc 2+·2NO − 3, N, N′-dimethyl-9,9′-biacridinium dinitrate) in dioxygen-saturated alkaline aqueous solutions of pH 10 has been examined utilizing modifications of electrodes (i.e. self-assembled monolayer (SAM)-modified gold electrodes) and of solutions (i.e. micellar solutions containing a nonionic surfactant, Triton X-100) for the first time. In both cases of the modifications, enhanced ECL was observed, and the ECL was considered to be derived from the decomposition of a dioxetane-type intermediate formed by the radical–radical coupling reaction between an electrogenerated superoxide ion (O 2 − ) and a one-electron reduced form of Luc 2+ (i.e. a radical cation, Luc + ). The surface modification of gold electrodes was achieved with dimercaptosuccinic acid (DMSA) and dl-thioctic acid ( dl-TA) having carboxyl end groups. The amount of ECL at dl-TA-SAM-modified electrodes was about five times as great as that at the bare electrode. The enhancement of ECL at the SAM-modified electrodes would be due to the concentration effect of positively charged Luc 2+ ions, the prevention of adsorption of the electrogenerated chemiluminescent product (i.e. N-methylacridone (NMA)) and the two-electron reduced form of Luc 2+ (Luc 0) on the electrode surfaces, and the effective generation of O 2 − . On the other hand, the amount of ECL in the micellar solution increased by about six times in comparison with that in the solution containing no surfactant. The enhanced ECL in micellar solutions would result mainly from the inhibition of adsorption of NMA and Luc 0 insoluble in water on electrode surfaces.

Comparative studies on the electrogenerated chemiluminescent and amperometric behavior of the Ru(bpy) 32+ system on a paraffin-impregnated graphite electrode and a glassy carbon electrode

The electrogenerated chemiluminescent (ECL) and amperometric behavior of Ru(bpy) 3 2+ system on a paraffin-impregnated graphite electrode (PIGE) and a glassy carbon electrode (GCE) was studied by different electrochemical techniques. Under conventional cyclic voltammetric (CV) conditions, two anodic ECL peaks (EP1 and EP2) (vs. SCE) were observed at 1.18 and 1.37 V for a PIGE, and at 1.20 and 1.44 V for a GCE. The EP1 normally occurred, but not the EP2. A complicated mechanism was involved in the formulation of EP2. A detection limit as low as 1×10 −9 mol l −1 of C 2O 4 2− was obtained on the PIGE by the CV method at 100 mV s −1. Strong ECL signals were found on both electrodes in either an oxalate-containing aqueous solution or an organic solution when a cyclic square wave (CSW), between two suitable potentials was used. However, the GCE showed higher reproducibility than the PIGE for continuous CSW ( n=10) measurements. Chronoamperometry was also applied by using a potential step from 0.15 to 1.85 V. It took 389 ms on a PIGE and 837 ms on a GCE to reach each maximal ECL intensity.

The electrogenerated chemiluminescent behavior of hemin and its catalytic activity for the electrogenerated chemiluminescence of lucigenin

The electrogenerated chemiluminescent (ECL) behavior of hemin at a platinum electrode in the alkaline solution has been investigated in detail. Under the optimum conditions the linear response range of hemin is 1.0×10 −5–1.0×10 −8 g ml −1, the detection limit was 1.0×10 −8 g ml −1, and the relative standard derivation for 1×10 −7 g ml −1 hemin was 2.8%. It has been also found that hemin would catalyze the ECL of lucigenin at a platinum electrode in a neutral solution in the presence of hydrogen peroxide, the catalytic ECL intensity was linear with the concentration of hemin in the range of 1.0×10 −14–1.0×10 −10 g ml −1. IgG labeled with hemin was used to examine the ECL catalytic activity of hemin after conjugating to protein, and the results showed that hemin retained ECL catalytic activity when conjugated to protein.

Electrogenerated Chemiluminescence of Methyl-9-(p-formylphenyl) Acridinium Carboxylate Fluorosulfonate and Its Applications to Immunoassay

Electrogenerated chemiluminescent (ECL) reaction of an acridinium ester, methyl-9-(p-formylphenyl) acridinium carboxylate fluorosulfonate (MFPA), on the surface of a platinum electrode has been studied using a homemade ECL apparatus. The ECL intensity was affected by the presence of micro amounts of chloride and hydrogen peroxide in the solution. A positive square wave pulse was exerted on the reaction cell. The applied voltage was 2.5 V (vs SCE). This method allowed MFPA to be determined in the range 1.0 × 10−9–4.0 × 10−7mol L−1. A line calibration plot was constructed in order to evaluate the limit of detection, which was determined to be 2.1 × 10−10mol L−1. The application of this method to immunoassay was demonstrated by the determination of human chorionic gonadotropin using MFPA as label. Good correlation was obtained between the results of the proposed method and the other method. A reaction mechanism study showed that MFPA decomposed toN-methylacridone and 4-hydrobenzaldehyde in the alkaline aqueous solution which contained hydrogen peroxide.N-Methylacridone could be oxidized to form an excited state molecule at the surface of the electrode. As some of these excited state molecules went to their ground state, they released light in the visible wavelength range. The ECL intensity enhanced by addition of chloride may be due to the oxidation of the chloride ion to OCl−and the latter acts on MFPA and then gives out luminescence.

An Electrogenerated Chemiluminescence Probe and Its Application Utilizing Tris(2,2‘-bipyridyl)ruthenium(II) and Luminol Chemiluminescence without a Flowing Stream

A novel electrogenerated chemiluminescent (ECL) probe that does not require a dark box to exclude ambient light has been developed. The probe is placed within the sample solution in a fashion similar to the use of a pH electrode. Thus, the flowing stream method of analyte introduction typically used for ECL analysis is not necessary. A fiber-optic bundle is utilized to carry the light produced within the probe to a photomultiplier tube for detection. Within the body of this probe is a three-electrode configuration necessary for ECL generation. The three ECL systems, luminol, tris(2,2‘-bipyridyl)ruthenium(III), and luminol coupled with an immobilized oxidase enzyme, have been used with this probe. The relative standard deviation for a typical sample was found to be 0.6%. Glucose determinations ranging from 3.0 to 1000 μM were made without a pH change for several real samples employing luminol and glucose oxidase immobilized within the probe body.

Determination of oxalate in urine and plasma using reversed-phase ion-pair high-performance liquid chromatography with tris(2,2'-bipyridyl)ruthenium(II)-electrogenerated chemiluminescence detection.

Oxalate is quantitated in both urine and plasma samples using reversed-phase ion-pair high-performance liquid chromatography (HPLC) with tris(2,2'-bipyridyl)ruthenium(II) [Ru(bpy)2+(3)]-electrogenerated chemiluminescent (ECL) detection. Underivatized oxalate was separated on a reversed-phase column (Zorbax ODS) using a mobile phase of 10% methanol in 100 mM phosphate buffer at pH 7.0. The eluted compounds were combined with a stream of 2 mM Ru(bpy)2+(3) at a mixing tee before the ECL flow-cell. In the flow-cell, Ru(bpy)2+(3) is oxidized to Ru(bpy)3+(3) at a platinum electrode, and reacts with oxalate to produce chemiluminescence (CL). Urine samples were filtered and diluted prior to injection. Plasma samples were deproteinized before injection. A 25-microliters aliquot of sample was injected for analysis. Possible interferants, including amino acids and indole-based compounds, present in biological samples were investigated. Without the separation, amino acids interfere by increasing the total observed CL intensity; this is expected because they give rise to CL emission on their own in reaction with Ru(bpy)3+(3). Indole compounds exhibit a unique interference by decreasing the CL signal when present with oxalate. Indoles inhibit their own CL emission at high concentrations. By use of the indicated HPLC separation, oxalate was adequately separated from both types of interferants, which thus had no effect on the oxalate signal. Urine samples were assayed by both HPLC and enzymatic tests, the two techniques giving similar results, differing only by 1%. Detection limits were determined to be below 1 microM (1 nmol/ml) or 25 pmol injected. The working curve for oxalate was linear throughout the entire clinical range in both urine and plasma.

Immobilization and Hybridization of DNA on an Aluminum(III) Alkanebisphosphonate Thin Film with Electrogenerated Chemiluminescent Detection

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTImmobilization and Hybridization of DNA on an Aluminum(III) Alkanebisphosphonate Thin Film with Electrogenerated Chemiluminescent DetectionXiao-Hong Xu and Allen J. BardCite this: J. Am. Chem. Soc. 1995, 117, 9, 2627–2631Publication Date (Print):March 1, 1995Publication History Published online1 May 2002Published inissue 1 March 1995https://doi.org/10.1021/ja00114a027RIGHTS & PERMISSIONSArticle Views673Altmetric-Citations162LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-AlertsSupporting Info (2)»Supporting Information Supporting Information Get e-Alerts

Electrogenerated chemiluminescent determination of codeine and related alkaloids and pharmaceuticals with tris(2,2′-bipyridine)ruthenium(II)

This work describes a novel and sensitive method for the determination of codeine, heroin, and dextromethorphan, using flow injection with electrogenerated chemiluminescence (ECL). The method is based on the ECL reaction of tris(2,2′-bipyridine)ruthenium(II)[Ru(bpy)22+] with tertiary amino groups. The factors affecting the determinations were investigated and possible reaction inhibitors, such as phenolic functional groups, were identified. Linear calibrations were obtained for signal (mV)versus concentration (µmol l–1) in the range 0.1–1.0 µmol l–1 with percentage relative standard deviations of less than 5%(n= 5). The 5σ limits of detection were calculated as 15, 45 and 44 nmol l–1 for codeine, heroin, and dextromethorphan, respectively.

Immobilization of DNA on an Aluminum(III) Alkanebisphosphonate Thin Film with Electrogenerated Chemiluminescent Detection

Immobilization of DNA on an Aluminum(III) Alkanebisphosphonate Thin Film with Electrogenerated Chemiluminescent Detection

Electrochemical studies of the interaction of metal chelates with DNA. 4. Voltammetric and electrogenerated chemiluminescent studies of the interaction of tris(2,2'-bipyridine)osmium(II) with DNA

Cyclic voltammetric and electrogenerated chemiluminescent data were used to study the binding of tris(2,2'-bipyridine)-osmium(II), Os(bpy)3(2+), an electrostatic binder, to calf thymus DNA. The oxidized form of the osmium complex, Os(bpy)3(3+), has a stronger association to DNA than the reduced form, Os(bpy)3(2+), as indicated by the negative shift of E0' of the CV waves (K3+/K2+ = 3.35). The calculated binding constant, K2+, and binding site size, s, for the Os(byp)3(2+)-DNA system depended slightly on whether a mobile or a static equilibrium was assumed. In 10 mM NaCl, 10 mM Tris pH 7, K2+ = (7.3 +/- 0.4) x 10(3) M-1 and s = 3 base pairs (mobile) and K2+ = (5.0 +/- 0.2) x 10(3) M-1 and s = 3 base pairs (static). Electrogenerated chemiluminescence (ECL) was produced upon oxidation of Os(bpy)3(2+) at a Pt electrode in a solution containing 10 mM C2O4(2-) and 10 mM phosphate at pH 5. Addition of DNA caused a decrease in the emission intensity (I); a plot of I vs relative DNA concentration yielded K2+ = (6.5 +/- 0.5) x 10(3) M-1 and s = 3 base pairs. The osmium complex produced ECL when bound to the DNA molecule with an efficiency of 30% that of the unbound chelate.

Electrogenerated chemiluminescent emission from an organized (L-B) monolayer of a tris(2,2'-bipyridine)ruthenium(2+)-based surfactant on semiconductor and metal electrodes

Electrogenerated chemiluminescence (ECL) from an organized monomolecular layer of a surfactant derivative of Ru(bpy)/sub 3//sup 2 +/ consisting of a single stearamidomethylene chain linked to one bipyridine unit at the 4-position and abbreviated Ru-(bpy)/sub 2/(bpy-C/sub 19/)/sup 2 +/ has been observed at the surfaces of In-doped tin oxide, Pt, and Au electrodes. The surfactant monolayer was coated on the substrate electrodes by the Langmuir-Blodgett method. ECL was generated in an electrochemical cell containing an aqueous oxalate solution by applying a positive potential to the electrode modified by the monolayer of Ru(bpy)/sub 2/(bpy-C/sub 19/)/sup 2 +/. The ECL of the emitter monolayer deposited on an In-doped SnO/sub 2/ electrode was quite intense with an emission maximum at ca. 680 nm. The ECL of the monolayer deposited on Pt and Au electrodes was generally 10/sup 2/-10/sup 3/ times weaker than that on SnO/sub 2/, but still easily detectable.