Peroxyoxalate Chemiluminescence Reaction Research Articles

L-tyrosine-based biocompatible low-toxic substrate of peroxyoxalate chemiluminescent reaction

We synthesized a biocompatible substrate of the peroxy-oxalate chemiluminescent reaction on the basis of N-benzoyl-L-tyrosine ethyl ester. Its ability to interact with hydrogen peroxide was evaluated by light emission in the presence of a perylene activator. Its cytotoxicity is three times less than that of bis[2,4,5-trichloro-6-(pentyloxycarbonyl)phenyl] oxalate (CPPO).

Chemiluminescent Read-Out of Degradable Fluorescent Polymer Particles

The design of chemiluminescent degradable particles is largely an unexplored field. We, herein, pioneer self-reporting chemiluminescent microspheres, allowing one to readily monitor their degradati...

A Photochemical Ligation System Enabling Solid‐Phase Chemiluminescence Read‐Out

The peroxyoxalate chemiluminescence (PO-CL) reaction is among the most powerful and versatile techniques for the detection of hydrogen peroxide (H2 O2 ) and has been employed in various biological and chemical applications over the past 50 years. However, its two-component nature (peroxyoxalate and fluorophore) limits its use. This contribution introduces an innovative and versatile photochemical platform technology for the synthesis of inherently fluorescent PO probes by exploiting the nitrile imine-mediated tetrazole-ene cycloaddition (NITEC) reaction. In the presence of hydrogen peroxide, the pioneered "2-in-1" molecule emits either yellow or blue light, depending on tetrazole (Tz) structure. Even in the absence of base, the emitted light remains visible and H2 O2 could be detected in the nanomolar range. Critically, the PO-Tz can be readily incorporated into polymeric materials. As a first application of this promising material, a tailor-made PO-Tz is grafted on poly(divinylbenzene) (PDVB) particles to enable solid-phase chemiluminescence on microspheres.

Peroxyoxalate Chemiluminescent Reaction as a Tool for Elimination of Tumour Cells Under Oxidative Stress

The overproduction of hydrogen peroxide is an inherent feature of some tumour cells and inflamed tissues. We took advantage of this peculiarity to eliminate cells using chemiluminescent peroxyoxalate reaction. We designed dispersions containing polyoxalate and tetramethylhematoporhyrin (TMHP) in dimethylphthalate droplets stabilized with Pluronic L64. The porphyrin plays the dual role. On the one hand, it serves as an activator of the peroxyoxalate reaction of polyoxalate with intracellular hydrogen peroxide and experiences excitation as a result of the reaction. The light emitted in the reaction in the model system without cells was used to optimize the dispersion’s composition. On the other hand, TMHP acts as a photosensitizer (PS) causing cell damage. The formation of singlet oxygen led to cell elimination if the dispersions were used in combination with inducers of oxidative stress: hydrogen peroxide, paraquat, antitumour drug doxorubicin, or a nutritional additive menadione. The PS-induced cytotoxicity correlated with the level of intracellular ROS. The developed approach targeted to endogenous ROS is orthogonal to the classical chemotherapy and can be applied to increase its efficiency.

Hydrazone as a new fluorophore in the peroxyoxalate chemiluminescence reaction

Peroxyoxalate chemiluminescence reactions involve the oxidation of oxalate ester by hydrogen peroxide (H2O2), forming intermediates capable of exciting fluorophores. These intermediates are known for their high sensitivity, quantum yield of chemiluminescence and wide linear range for analyte detection. This study aims at the application of complexing agents di-2-pyridyl ketone benzoylhydrazone and di-2-pyridyl ketone salicyloylhydrazone, or these agents complexed with Pb(II) as fluorophores, as well as use of these reactions for metal determination. Both complexing agents have fluorescent properties, however only the former could be applied. The buffering system used was HCO3-/CO3-2, pH 10.3 and the ester bis(2,4,6-triclorophenyl) oxalate, prepared in 1,2-dimethoxyethane. The addition of Pb(II) to the peroxyoxalate chemiluminescence reaction makes the signal decrease by 36%. Through the Stern-Volmer equation, it was possible to determine the ion within a range from 2.07 to 41.4mgL-1(R2 0.9894), with detection and quantification limits of 0.45mgL-1 and 1.5mgL-1, respectively.

Micelles of amphiphilic copolymers as a medium for peroxyoxalate chemiluminescent reaction in water environment

The peroxyoxalate chemiluminescent reaction of bis(4-nitrophenyl) oxalate or bis(pentachlorophenyl) oxalate with hydrogen peroxide in the presence of hematoporhyrin IX water-insoluble derivative in micelles or associates of Pluronics F68, L64, L61 and the alternating copolymer dimethyl siloxane-ethylene oxide is investigated. Pluronic L61, which forms large clusters in solution, has the greatest impact on the reaction quantum yield. The micelles influence on the efficiency of the reaction with bis(pentachlorophenyl) oxalate is stronger in comparison to that with bis(4-nitrophenyl) oxalate. The chemiluminescence quantum yield increases with the concentrations of fluorophore and hydrogen peroxide. If the polymer content is being varied, quantum yield passes through the maximum, which corresponds to the largest amount of particles containing both oxalate and porphyrin.

Response surface optimized peroxyoxalate chemiluminescence of octahydro-Schiff base derivative as new luminophor and study of the quenching effect of some cations, amino acids and cholesterol.

We report the first detailed study of the characteristics of an octahydro-Schiff base derivative as a new luminophor in the peroxyoxalate chemiluminescence (POCL) system. The effect of reagents on this new POCL system was investigated. In addition, the response surface methodology was used for evaluating the relative significance of variables in this POCL system, establishing models and determining optimal conditions. The quenching effect of some cations and compounds such as Cu(2+), Fe(3+), Hg(2+), imidazole, histidine and cholesterol on an optimized POCL reaction were studied. The dynamic ranges were up to approximaterly 100 and 175 × 10(-6) M for Cu(2+) and cholesterol respectively. The detection limits were 3.3 × 10(-6) m and 2.58 × 10(-6) m for Cu(2+) and histidine, respectively. In all cases the relative standard deviations were 4-5% (n = 4).

Chemically-induced geometrical isomerization of stilbenes during peroxyoxalate chemiluminescence reaction: revisit to ‘photochemistry without light’

The chemically-induced isomerization of stilbenes during the peroxyoxalate chemiluminescence (PO-CL) reactions was reinvestigated. The PO-CL reactions using bis(2,4,6-trichlorophenyl) oxalate in the presence of several stilbenes (type A reaction) produced cis-stilbenes in 0–4% yields, which was dependent on the singlet excitation energy of the stilbenes. On the other hand, the PO-CL reactions of the oxalates, containing the stilbene moieties in the molecules (type B reaction), produced cis-stilbenes 0–9.3% yields, some of which were much more effective than the type A reactions considering the amount of the oxalate moiety as the energy supplier.

Simple and fast PO-CL method for the evaluation of antioxidant capacity of hydrophilic and hydrophobic antioxidants

A simple and fast procedure is described for evaluating the antioxidant activity of hydrophilic and hydrophobic compounds by using the peroxyoxalate-chemiluminescence (PO-CL) reaction of Bis(2,4,6-trichlorophenyl) oxalate (TCPO) with hydrogen peroxide in the presence of di(tert-butyl)2-(tert-butylamino)-5-[(E)-2-phenyl-1-ethenyl]3,4-furandicarboxylate as a highly fluorescent fluorophore. The IC50 values of the well-known antioxidants were calculated and the results were expressed as gallic equivalent antioxidant capacity (GEAC). It was found that the proposed method is free of physical quenching and oxidant interference, for this reason, proposed method is able to determine the accurate scavenging activity of the antioxidants to the free radicals. Finally, the proposed method was applied to the evaluation of antioxidant activity of complex real samples such as soybean oil and sunflower oil (as hydrophobic samples) and honey (as hydrophilic sample). To the best of our knowledge, this is the first time that total antioxidant activity can be determined directly in soybean oil, sunflower oil and honey (not in their extracts) using PO-CL reactions.

The Hammett correlation between distyrylbenzene substituents and chemiluminescence efficiency providing various ρ-values for peroxyoxalate chemiluminescence of several oxalates

Abstract Peroxyoxalate chemiluminescence (PO-CL) was investigated using eight oxalates with various phenol moieties and the distyrylbenzene (DSB) fluorophores with various substituents. The ρ -values in the Hammett correlation between the substituent constants (σ p + ) of the DSBs and the singlet chemiexcitation yields ( Φ S ) for the PO-CL reactions varied from −0.50 to −1.01 depending on the oxalate structure, and the reactive oxalates tended to afford the higher absolute ρ -values but with a few exceptions. Based on the CIEEL mechanism, these experimental observations suggest that the aryloxy groups still remain in the 1,2-dioxetanones (DOTs), which are the postulated high-energy intermediates, and control the electronic properties of DOTs as electron-acceptors. The LUMO energies of the DOTs calculated by the ab initio method with a B3LYP/6-31g(d) basis set reveal that the lower the DOT-LUMO energies, the higher the absolute ρ -values were provided for the corresponding oxalates, as predicted by the frontier molecular orbital (FMO) theory. Thus, the chemical species interacting with the DSBs would be not unitary and will be DOTs.

Age‐related changes of dopamine, noradrenaline and adrenaline in adrenal glands of mice

Catecholamines, which are physiologically important neurotransmitters and hormones, apparently decrease in the brain and plasma as some species age. Because this observation has engendered controversy, we used mice to investigate whether age-related changes occur in adrenal catecholamine levels and in the expression of catecholamine synthetic enzymes. Adrenal glands were collected from male C57BL/6NCr mice at the ages of 6, 12 and 24 months. Catecholamines, such as dopamine (DA), noradrenaline (NA) and adrenaline (AD) from those glands, were measured by using a highly sensitive liquid chromatographic method with peroxyoxalate chemiluminescence reaction detection. Tyrosine hydroxylase (TH), dopa decarboxylase, dopamine beta hydroxylase (DBH) and phenylethanolamine N-methyltransferase (PNMT) mRNA expression levels were measured by quantitative real-time polymerase chain reaction. Although DA levels in the adrenals of 24-month-old mice were higher than in 6- and 12-month-old mice, the AD content decreased with age. In such mice, the ratio of DA to NA at 24 months was lower than at 12 months, and the ratio of NA to AD content at 24 months was significantly lower than at 6 months. The mRNA expression ratios in TH, DBH and PNMT in 24-month-old mice were all lower than in 12-month-old mice. These results strongly suggest that catecholamine synthesis, in general, declines with aging in the adrenal glands of mice and that AD, in particular, undergoes a significant decrease with advancing age.

The fast peroxyoxalate-chemiluminescence of 3-1-aza-4,10-dithia-7-oxacyclododecane as a novel fluorophore

Due to their multiple selectivities, high sensitivity, and instrumental simplicity peroxyoxalate chemiluminescence (PO-CL) reactions have been used as powerful detection systems in several separation techniques. However many of the PO-CL reactions have slow kinetics and impose extra flow elements in separation systems to obtain acceptable band resolution, overcome the peak broadening and observe the reaction in a reasonable time window at maximum emission intensity. Therefore slow chemiluminescence reactions cannot be used in constructing miniaturized separation systems. To achieve the fast and intense PO-CL reactions (suitable for miniaturized separation systems) careful selection of the fluorophore molecule and the reaction conditions is of great importance. In this work, the time-dependent light emission of the fast chemiluminescence (CL) arising from the reaction of bis(2,4,6-trichlorophenyl)oxalate (TCPO) with H2O2 in the presence of 3-1-aza-4,10-dithia-7-oxacyclododecane (L) as a novel fluorophore, and imidazole as catalyst, has been studied in ethyl acetate solution. To find the best time-intensity emission curves the concentration of TCPO, imidazole, hydrogen peroxide and L were optimized. The maximum CL intensity and minimum reaction time were obtained at the concentration of 0.2M H2O2, 2.0×10−3M TCPO, 1.0×10−3M fluorophore and 5.0×10−3 imidazole. Under the optimum experimental condition, the entire CL reaction is completed in less than 3s.

Highly sensitive glucose biosensor based on the effective immobilization of glucose oxidase/carbon-nanotube and gold nanoparticle in nafion film and peroxyoxalate chemiluminescence reaction of a new fluorophore

A novel glucose biosensor based on the chemiluminescence (CL) detection of enzymatically generated H2O2 was constructed by the effective immobilization of glucose oxidase (GOD)/carbon-nanotubes (CNTs)/gold nanoparticles (GNPs) in nafion film on graphite support. The influences of various experimental parameters such as solution pH, the action time of the enzyme, interferents and the concentration of CL reagents were investigated. Carbon nanotubes and gold nanoparticles offer excellent catalytic activity toward hydrogen peroxide generation in enzymatic reaction between glucose oxidase and glucose, which would enable sensitive determination of glucose.Under the optimum condition, the linear response range of glucose was found to be 2.25×10−6 to 1.75×10−4molL−1, and the detection limit (defined as the concentration that could be detected at the signal-to-noise ratio of 3) was 1.00×10−6molL−1. The CL biosensor exhibited good storage stability, i.e., 80% of its initial response was retained after 10 days storage at pH 7.0. The present CL biosensor has been used to determine the glucose concentrations in real serum and urine samples with satisfactory results.

Catecholamine analysis with strong cation exchange column liquid chromatography–peroxyoxalate chemiluminescence reaction detection

A liquid chromatography-chemiluminescence detection method was developed and validated for the determination of catecholamines (norepinephrine, epinephrine, and dopamine) in mouse brains. Chromatography was performed on a strong cation exchange column (150 × 2.0-mm id) using an isocratic mobile phase of 65 mM potassium acetate/75 mM potassium phosphate (95:5, pH 3.5) at a flow rate of 0.2 mL/min following post-column fluorescence derivatization of catecholamines with ethylenediamine and peroxyoxalate chemiluminescence reaction detection. The recovery of catecholamines added to mouse brain samples was more than 95.0%, while intra- and inter-day precision of the assay were <4.8%. The validated method was used to determine norepinephrine and dopamine concentrations in mouse brains without prior sample purification.

Sensitive and selective determination of glucose in human serum and urine based on the peroxyoxalate chemiluminescence reaction of a new Fluorophore

A novel method for simple and sensitive determination of glucose based on the peroxyoxalate chemiluminescence (PO-CL) detection of enzymatically generated H 2O 2 was investigated. Influence of various experimental parameters on glucose sensing, including the action time of the enzyme, solution pH, interferents and the concentration of CL reagents was investigated. Under the optimum condition, the linear response range of glucose was found to be 2.50 × 10 −6 to 1.75 × 10 −4 mol/L, and the detection limit (defined as the concentration that could be detected at the signal-to-noise ratio of 3) was 1.10 × 10 −6 mol/L. The present method has been used to determine the glucose concentrations in real serum and urine samples with satisfactory results.

Control of peroxyoxalate chemiluminescence by nitrogen-containing ligand quenching: turning off and on by ligand–metal ion host–guest interactions

The control of peroxyoxalate chemiluminescence (PO-CL) by the coordination of nitrogen-containing ligands and metal cations was investigated. Turning the CL off and on was done by PO-CL using 15-monoazacrown-5-tethered anthracene and alkali metal ions. CL quenching and regeneration was also observed in the separated molecular system of 15-monoazacrown-5 and the fluorophores. CL quenching by a number of ligands bearing dipicolylamino groups was evaluated by these PO-CL reactions and found to be closely related to their oxidation potentials, which is dependent on the Weller rate law for electron exchange and this provides strong support for the existence of the CIEEL PO-CL process. When Zn 2+ or Cu 2+ are added to the PO-CL system quenched by the ligand, N-[2-(2,2′-dipicolylamino)ethyl]aniline, CL was turned on because the electron donating ability of the ligands was modulated. This was controlled by the coordination of the studied metal ions and, therefore, this system results in CL because of host–guest interactions.

Evidence of multiple pathways capable of emitting peroxyoxalate chemiluminescence using a charge coupled devicespectrometer

Peroxyoxalate chemiluminescence (PO-CL) spectra obtained simultaneously and continuously using a CCD spectrometer provide evidence of the complexity of PO-CL reactions.

Effect of Deputy Group Metal Ions on the Fluorescent Properties of the CPPO-H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt;-Rhodamine B System

The influence of metal ions on the peroxyoxalate chemiluminescence reaction was investigated. A number of metal ions showed the quenching effect of the chemiluminescence reaction of bis (3, 5, 6- trichloro-2-carbopentyloxy) oxalate with hydrogen peroxide in the presence of Rhodamine B as the fluorophore. Copper ion gave the highest quenching effect. The reason for the decrease in the chemiluminescence intensity by metal ions is probably a change in the conjugative structure of Rhodamine B due to combination of metal ions and Rhodamine B

Molecularly imprinted polymer-based chemiluminescence array sensor for the detection of proline

A new molecularly imprinted polymer (MIP)–chemiluminescence (CL) method has been developed for detection of proline. The molecularly imprinted polymer microspheres were synthesized using precipitation polymerization with hydroxyproline, a structural analogue, as the template. Polymer microspheres were immobilized in microtiter plates (96 wells) which selectively adsorbed the analyte (dansyl-proline). After washing, the bound fraction was quantified based on peroxyoxalate chemiluminescence (PO-CL) reaction enhanced by imidazole. The cavity of MIP synthesized with hydroxyproline as template is smaller, which can avoid non-specific adsorption and lead to enhancement of specificity, response speed and sensitivity when recognizing dansyl-proline. Under the optimum conditions, the relative CL intensity has a linear relationship with the concentration of proline in the range of 1 × 10 −6 mol L −1 to 4 × 10 −5 mol L −1, with a limit of detection 3 × 10 −7 mol L −1 (3 σ). The relative standard deviation (R.S.D.) for proline (1 × 10 −6 mol L −1, n = 7) was 3.7%. The MIP–CL method can become a useful analytical technology for determination of proline in real sample.

Enhancement of peroxyoxalate chemiluminescence intensity by surfactants and its application to detect detergent

Enhancement of peroxyoxalate chemiluminescence (PO-CL) intensity by a surfactant in the H(2)O(2)/bis(2,4,6-trichlorophenyl)oxalate (TCPO)/rhodamine B system was described. The effects of 15 surfactants were evaluated by comparing the ratio of a relative CL intensity (RCI) with surfactant to that of the blank in each system. In preliminary study, H(2)O(2)/imidazole-HNO(3) buffer/TCPO/rhodamine B system was used to study the effects of surfactants on PO-CL intensity. Fourteen surfactants reduced the CL intensity at the 2% concentration, where their relative CL intensities ranged from 0.6 to 93.5%. Some of these phenomena may be caused by a notable change of pH that was occurred by adding the surfactant. Additionally, enhancement of PO-CL intensity was studied by using system (1) H(2)O(2)/TCPO/rhodamine B and (2) H(2)O(2)/imidazole-HNO(3) buffer/TCPO/systems. In the system 1, the favorable enhancement of CL intensity (ranged from 124 to 472%) was observed with 9 surfactants at the 0.5% concentration. This result suggested that several surfactants might play a role as a catalyst in the PO-CL reaction. There was no tendency to enhance CL intensity among the surfactant types. In the system 2, the enhancement of CL intensity was also observed by adding with 11 surfactants, which might be mainly caused by the fluorescent impurities of surfactants used. Furthermore, detection of detergent commercially available was applied by using the system 1.