Luminescent oxidation

There are many kinds of luminous organisms that utilize coelenterazine as their luciferin. These organisms possess luciferases to catalyze the luminescent oxidation of coelenterazine. Coelenterazine luciferases have been isolated from about 10 kinds of organisms, including the anthozoans Renilla and Ptilosarcus, the scyphozoan... 

Shimomura, O., and Johnson, F. H. (1971). Mechanism of the luminescent oxidation of Cypridina luciferin. Biochem. Biophys. Res. Commun. 44 340-346. 

Luminescent oxides (or phosphors) play an important role in television receivers and other cathode ray tube (CRT) applications, fluorescent lamps, scintillation counters, and information display devices including CRT and flat panel display (FPD) as well as the emerging plasma display... 

E. Hemmer, V. Huch, M. Adlung, C. Wickeder and S. Mathur, Homo- and heterometallic terbium alkoxides - Synthesis, characterization and conversion to luminescent oxide nanostructures, Eur. J. Inorg. Chem., vol. 2011, no. 13, pp. 2148-2157, 2011. 

McKittrick, J., Shea, L.E., Bacalski, C.F., Bosze, E.J. The influence of processing parameters on luminescent oxides produced by combustion synthesis. Displays 19, 169—172 (1999)... 

G.A. Hirata, J. McKittrick, D. Devlin, Growth and analysis of red, green and blue luminescent oxide thin films. Surf. Rev. Lett. 5(1), 413-417 (1998)... 

These light-producing oxidations are quite different reactions in each of the three most thoroughly studied organisms, Cypridina, bacteria, and fireflies (382,566,567,569,709,761). The structures of the two luciferins, LHk and LHjf, and of their oxidation products (oxyluciferins , 568), and the fate of the long-chain fatty aldehyde which acts as cofactor in bacterial luminescent oxidation of FMNH, are all unknown. Each luminescent system requires molecular oxj en and a potential source of electrons, in common with mixed function oxidases, but the significance of these characteristics in terms of oxidase classification remains to be determined. 

The collected results of experiments with crude and purified luciferin (99,100) indicate that it is a relatively small molecule, soluble in water, dilute acid, alkali and salt solutions, diffusible through cellophane, nonanti-genic, and not destroyed by trypsin. It has been estimated that luminescence visible to the dark-adapted eye may be obtained from luciferin in a dilution of 1 40,000,000,000 (94). With regard to some of the properties of luciferin, based on results obtained with crude extracts, it would be desirable to repeat the experiments with the purified material, inasmuch as different results are sometimes observed, e.g., cyanide apparently has no effect on the luminescent oxidation in crude extracts (91,185) but combines irreversibly with the luciferin in purified solutions (82). 

Since the preparation of the first simple diazaquinones [53, 54] (all of them being non-chemiluminescent ) chemiluminescent diazaquinones have been described. It should be pointed out that luminol diazaquinone has not been isolated as yet, nor has it been isolated from luminescent oxidation mixtures, except as the Diels-Alder adduct mentioned above. 

Detecting the presence of small, even invisible, amounts of blood is routine. Physical characteristics of dried stains give minimal information, however, as dried blood can take on many hues. Many of the chemical tests for the presence of blood rely on the catalytic peroxidase activity of heme (56,57). Minute quantities of blood catalyze oxidation reactions between colorless materials, eg, phenolphthalein, luco malachite green, luminol, etc, to colored or luminescent ones. The oxidant is typically hydrogen peroxide or sodium perborate (see Automated instrumentation,hematology). 

Chemiluminescent Immunoassay. Chemiluminescence is the emission of visible light resulting from a chemical reaction. The majority of such reactions are oxidations, using oxygen or peroxides, and among the first chemicals studied for chemiluminescence were luminol (5-amino-2,3-dihydro-l,4-phthalazinedione [521-31-3]) and its derivatives (see Luminescent materials, chemiluminescence). Luminol or isoluminol can be directly linked to antibodies and used in a system with peroxidase to detect specific antigens. One of the first appHcations of this approach was for the detection of biotin (31). 

Subsequent studies (63,64) suggested that the nature of the chemical activation process was a one-electron oxidation of the fluorescer by (27) followed by decomposition of the dioxetanedione radical anion to a carbon dioxide radical anion. Back electron transfer to the radical cation of the fluorescer produced the excited state which emitted the luminescence characteristic of the fluorescent state of the emitter. The chemical activation mechanism was patterned after the CIEEL mechanism proposed for dioxetanones and dioxetanes discussed earher (65). Additional support for the CIEEL mechanism, was furnished by demonstration (66) that a linear correlation existed between the singlet excitation energy of the fluorescer and the chemiluminescence intensity which had been shown earher with dimethyl dioxetanone (67). 

Examples include luminescence from anthracene crystals subjected to alternating electric current (159), luminescence from electron recombination with the carbazole free radical produced by photolysis of potassium carba2ole in a fro2en glass matrix (160), reactions of free radicals with solvated electrons (155), and reduction of mtheiiium(III)tris(bipyridyl) with the hydrated electron (161). Other examples include the oxidation of aromatic radical anions with such oxidants as chlorine or ben2oyl peroxide (162,163), and the reduction of 9,10-dichloro-9,10-diphenyl-9,10-dihydroanthracene with the 9,10-diphenylanthracene radical anion (162,164). Many other examples of electron-transfer chemiluminescence have been reported (156,165). 

Zinc compounds are generally colorless unless the other component, eg, chromate, is colored. The lack of color of most zinc compounds in visible light is a great advantage in that they do not color paint films, plastics, mbber, cosmetics, etc. However, when excited by various types of radiation and at various temperatures, zinc oxide, sulfide, selenide [1315-09-9], and related compounds exhibit luminescence, ie, they emit colored light (see Luminescent materials). Zinc-based phosphors can be produced in many colors, depending upon the added dopants. They are used in television tubes, luminescent glasses, and various specialty products. 

Chemiluminescent labels, in which the luminescence is generated by a chemical oxidation step, and bioluminescent labels, where the energy for light emission is produced by an enzyme-substrate reaction, are additional labeling types (39,42). Luminol [521 -31 -3] CgHyN202, and acridine [260-94-6] C H N, derivatives are often used as chemiluminescent labels. 

The cadmium chalcogenide semiconductors (qv) have found numerous appHcations ranging from rectifiers to photoconductive detectors in smoke alarms. Many Cd compounds, eg, sulfide, tungstate, selenide, teUuride, and oxide, are used as phosphors in luminescent screens and scintiUation counters. Glass colored with cadmium sulfoselenides is used as a color filter in spectroscopy and has recently attracted attention as a third-order, nonlinear optical switching material (see Nonlinear optical materials). DiaLkylcadmium compounds are polymerization catalysts for production of poly(vinyl chloride) (PVC), poly(vinyl acetate) (PVA), and poly(methyl methacrylate) (PMMA). Mixed with TiCl, they catalyze the polymerization of ethylene and propylene. 

Physiological Role of Citric Acid. Citric acid occurs ia the terminal oxidative metabolic system of virtually all organisms. This oxidative metabohc system (Fig. 2), variously called the Krebs cycle (for its discoverer, H. A. Krebs), the tricarboxyUc acid cycle, or the citric acid cycle, is a metaboHc cycle involving the conversion of carbohydrates, fats, or proteins to carbon dioxide and water. This cycle releases energy necessary for an organism s growth, movement, luminescence, chemosynthesis, and reproduction. The cycle also provides the carbon-containing materials from which cells synthesize amino acids and fats. Many yeasts, molds, and bacteria conduct the citric acid cycle, and can be selected for thek abiUty to maximize citric acid production in the process. This is the basis for the efficient commercial fermentation processes used today to produce citric acid. 

In this work the development of mathematical model is done assuming simplifications of physico-chemical model of peroxide oxidation of the model system with the chemiluminesce intensity as the analytical signal. The mathematical model allows to describe basic stages of chemiluminescence process in vitro, namely spontaneous luminescence, slow and fast flashes due to initiating by chemical substances e.g. Fe +ions, chemiluminescent reaction at different stages of chain reactions evolution. 

OXIDATIVE LUMINESCENCE OF UV ABSORBING CHEMICALS. APPLICATION TO THEIR DETERMINATION IN SUNSCREEN PRODUCTS BY REVERSED PHASE LIQUID CHROMATOGRAPHY WITH CHEMILUMINESCENCE... 

The conducted researches of complexing processes of noble metals on a sulfur-containing CMSG surface formed the basis for development of sorption-photometric, sorption-luminescent, soi ption-atomic-absoi ption, sorption-atomic-emission and sorption-nuclear-physic techniques of the analysis of noble metals in rocks, technological objects and environmental objects. Techniques of separation and detenuination of noble metals in various oxidation levels have been proposed in some cases. 

Nonstoichiometric oxide phases are of great importance in semiconductor devices, in heterogeneous catalysis and in understanding photoelectric, thermoelectric, magnetic and diffusional properties of solids. They have been used in thermistors, photoelectric cells, rectifiers, transistors, phosphors, luminescent materials and computer components (ferrites, etc.). They are cmcially implicated in reactions at electrode surfaces, the performance of batteries, the tarnishing and corrosion of metals, and many other reactions of significance in catalysis. ... 

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