Peroxide sensitizers

SASPs comprise about 10-20% of the protein in the dormant spore, exist in two forms alfi and y) d are degraded during germination. They are essential for expression of spore resistance to ultraviolet radiation and also appear to be involved in resistance to some biocides, e.g. hydrogen peroxide. Spores (a /3 ) deficient in a//3-type SASPs are much more peroxide-sensitive than are wild-type (normal) spores. It has been proposed that in wild-type spores DNA is saturated with a/j3-type SASPs and is thus protected from free radical damage. 

Cardosi MR 1994. Hydrogen peroxide-sensitive electrode based on horseradish peroxidase-modified platinized carbon. Electroanalysis 6 89-96. 

As mentioned earlier, reversed micelles have different properties from normal micelles. These properties have the potential to favorably affect the sensitivity and other analytical aspects of CL reactions. Thus, reversed micelles have been used to prolong the duration of the observed CL of various oxalate ester (or acid)-hydrogen peroxide-sensitizer reaction systems for application as chemical light sources [62],... 

S. Razola Serradilla, B. Ruiz Lopez, N. Diez Mora, H.B. Mark and J.M. Kauffmann, Hydrogen peroxide sensitive amperometric biosensor based on horseradish peroxidase entrapped in a polypyrrole electrode, Biosens. Bioelectron., 17(11-12) (2002) 921-928. 

Peroxide Sensitizers. Poly(methylmethacrylate), PMMA, is the first polymer reported to exhibit an increase in refractive index upon irradiation with uv light (41). Irradiation at either 325 nm (Cd laser) or 365 nm (Hg arc) was found to give an index increase of up to 0.3%, and the resolution, determined from gratings, was shown to be at least 5000 lines/mm. Applications to optical waveguides and holographic elements were suggested. This phenomenon was a serendipitous discovery. The PMMA had been intended for use as an inert matrix for reversible photodimerization when its own photosensitivity was uncovered. 

An interesting use of peroxide-sensitized PMMA was for the fabrication of a solid dye laser with an internal grating... 

Peroxide-sensitized PMMA is an attractive low-loss material for experimental thick holograms and internal light guides but because of its low and irreproducible sensitivity, it is not a practical material. 

Semiconductor fabrication techniques have also been successfully applied to the construction of conventional transducers sensitive to hydrogen peroxide, oxygen, and carbon dioxide, A hydrogen peroxide-sensitive silicon chip was made by using metal deposition techniques (28,29). The combination of the hydrogen peroxide-sensitive transducer and enzyme-immobilized membranes gave a miniaturized and multifunctional biosensor. Similarly, an oxygen- and a carbon dioxide-sensitive device was made cmd applied to the construction of biosensors (25, 30, 31). 

Dangerous fire hazard when exposed to heat, flame, or powerful oxidizers. Upon exposure to air it forms explosive peroxides sensitive to heat, shock, or heating above 27°C. May decompose explosively when heated above 200°C/1.0 kbar. Explodes on contact with aluminum tetrahydroborate. Potentially explosive reaction with NOx +... 

D. Wang et al., NADPH-oxidase and a hydrogen peroxide-sensitive channel may function as oxygen sensor complex in airway chemoreceptors and small cell lung carcinoma cell lines, Proc. Natl. Acad. Sci. USA 93 (1996) 13182-13187. 

Aizawa (1982) patented a lectin electrode based on the binding of horseradish peroxidase via its carbohydrate groups to con A immobilized on a hydrogen peroxide sensitive probe. The bound enzyme activity was determined from the H2O2 consumption catalyzed by HRP. 

Rabek [500, 502] found that benzoyl peroxide, butyl peroxide and cumyl peroxide sensitize the photodegradation of c/s-l,4-polyisoprene in benzene. Similarly, anthracene peroxide added to a benzene solution of polystyrene shows a strong photosensitizing effect only when oxygen is present [504]. 

P. berghei isolated from mouse red blood cells also contains a cyanide-sensitive SOD activity. Plasmodial and mouse enzymes are indistinguishable electrophoretically. These results suggest that the malarial cyanide-sensitive SOD may be entirely of host origin and stored by the parasite. Accordingly, plasmodium isolated from mouse red blood cells contain mouse cyanide-sensitive SOD, whereas rat-derived parasites contain the rat enzyme (78). Another, peroxide-sensitive, apparently manganese-containing SOD, has been described in P. falciparum (79). Two Babesia species (B. hylomysci and... 

In a later investigation of the benzoyl peroxide sensitized photo-pol3mierization of st3Tene, Melville and Valentine (Trans. Faraday Soc. 1950, 46, 210) avoided the determination of the rate of initiation and... 

Sergeyeva TA, Lavrik NV, Rachkov AE et al. Hydrogen peroxide-sensitive enzyme sensor based on phthalocyanine film. Analytica Chimica Acta 1999 391 289-297. 

To one such slide, a tissue dampened with 0.1 N HCl, 2% starch and 10% potassium iodide solution (made fresh daily) is applied. A weak color reaction, which is much stronger at the locations of charcoal flecks and any white droplets are potassium oxides and carbonate. A tissue overlay of hexamethylene rosaniline hydrochloride (crystal violet) is applied to another fresh slide. Bleaching and pH effects are observed. Other pH indicators and other peroxide sensitive solutions should be applied. The author finds that thickening the reagents with carbohydrate and polyvinyl alcohol to slow diffusion rates is advisable in some cases. 

Dimethyl Ether - CjHgO, 115-10-6 flammable, inhalation and skin irritant, narcotic properties bp = -23.7 "C [-10.7"F] er = 3.4-27% sp g = 1.62 OSFIA PEL = NA. Explosion hazard when exposed to flames, sparks, forms peroxides, sensitive to heat. 

Wu M., Z. H. Lin, M. Schaferling, A. Durkop, O. S. Wolfbeis. Fluorescence imaging of the activity of glucose oxidase using a hydrogen-peroxide-sensitive europium probe, Aruil. Biochem., 340, 66—73 (2005). 

Inteiference with the reactants — An error in the measurement may arise if a compound reacts with a cosubstrate or a reaction product For example, ascorbic acid reacts with oxygen and interferes with the determination of glucose by an amperometric electrode that measures the reduction in the partial pressure of oxygen. This interference is lower when a peroxide-sensitive transducer is used, since this detects the production of H2O2. 

Freeman and Seitz [11] exploited the above reaction to produce a hydrogen peroxide-sensitive optical biosensor. Here, the luminol must be in excess with respect to H2O2 and the peroxidase must be immobilized on transparent polyacrylamide to ensure the best transmission of the chemiluminescence. A compromise must be adopted between the optimal pH of peroxidase, which produces a maximal amount of activated compound, and the optimal pH for the fluorescence occurring when the activated product arising from the luminol falls back to its ground state. The best compromise is achieved with a luminol concentration of 10 M and pH 9. 

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