Porphyrins fluorescence

Porphyrins consist of a tetrapyrrole ring with variable side chains. The physiological compounds are the reduced forms, the porphyrinogens that do not fluoresce. They react spontaneously with oxygen in the air to the strongly fluorescent porphyrins. 

The method is dependent on the conversion of the haem moiety to its fluorescent porphyrin derivative by incubation with oxalic acid. 

Beswick, R. B., and C. W. Pitt. 1988. Optical detection of toxic gases using fluorescent porphyrin Langmuir-Blodgett films. 7. Colloid Interface Sci. 124(f) 146-55. 

Amao, Y. Komori, T. Optical CO2 sensor of the combination of colorimetric change of a-naphthol-phthalein in poly(isobutyl methacrylate) and fluorescent porphyrin in polystyrene. Talanta 2005, <56, 976-981. 

Amao Y (2003) Probes and polymers for optical sensing of oxygen. Mikrochim Acta 143 1-12 Amao Y, Nakamura N (2004) Optical CO2 sensor with the combination of colorimetric change of a-naphtholphthalein and internal reference fluorescent porphyrin dye. Sens Actuators B 100 347-351 Ando M, Kobayashi T, Haruta M (1994) Enhancement in the optical CO sensitivity of NiO film by the deposition of ultrafine gold particles. J Chem Soc Faraday Trans 90 1011-1013 Ando M, Kobayashi T, Haruta M (1995) Optical CO detection by use of CuO/Au composite films. Sens Actuators B 24-25 851-853... 

For cytochrome c oxidase, distances between subunit It, heme a and cytochrome c bound to subunit III could be estimated.Subunit II was labelled at a thiol group with A -(iodoacetamidoethyl)-l-aminonaphthalene-5-sulphonic acid and subunit III with either thionitrobenzoate-activatcd cytochrome c or a fluorescent porphyrin analogue. In this study factors allowing for the probable orientation of groups were included, being estimated from fluorescence depolarization measurements. The distances between subunit II and heme a, subunit II and cytochrome c (bound to subunit III) and between cytochrome c (bound to subunit III) and heme a were estimated to be 52, 35, and 25 A respectively. 

Ruhlmann, L., Zimmermann, J., Fudicker, w., Roeder, B. and Fuhrhop, J.-H., Hydrophobic Membrane Gaps on Gold with a Fluorescing Porphyrin Base, J. Am. Chem. Soc.y submitted for publication. 

Amao Y, Nakamura N (2004) Optical CO2 sensor with the combination of colorimetric change of a-naphtholphthalein and internal reference fluorescent porphyrin dye. Sensor Actual B 100 347-351... 

Fig. 51 Fluorescence intensities of porphyrins as a function of the concentration of the paraffin oil dipping solution mesoporphynn, coproporphynn, pentaporphynn...

Fig. 52 Fluorescence intensity of porphyrin chromatogram zones as a function of time after dipping in 50% liquid paraffin solution and storage in darkness. —...

Isooctane porphyrin methyl esters reactivation of faded fluorescence benzene and petroleum ether can be employed in the same way [233, 289]... 

This IS used for synthesis of porphobilinogen fEq 10 24 Porphobilinogen is the key building block in the biosynthesis of pigments of life such as porphyrins, heme, and vitamin Interestmg application of porphobdiogen to synthesis of immunocomponents for the measurement of lead fPb by fluorescence polarizadon Immunoassay has been reported "... 

Fluorescence stabilization, porphyrins la 100-101 Fluorophors la 57 Flupentixol lb 354 Fluphenazine la 104 lb 354-356 Fluspirilen lb 354 Fluvalinates lb 86 Foam bath, brominated la 64 Folic acid la 223,225 Folin-Ciocalteu s reagent lb 180 Folin s reagent lb 321 Formaldehyde la 299,351 -, vapor la 86 Formazan lb 65... 

When porphyrins dissolved in strong mineral acids or in organic solvents are illuminated by ultraviolet hght, they emit a strong red fluorescence. This fluorescence is so characteristic that it is often used to detect small amounts of free porphyrins. The double bonds joining the pyrrole rings in the porphyrins are responsible for the characteristic absorption and fluorescence of these compounds these double bonds are absent in the porphyrinogens. 

Nishitani et al. observed the tip-enhanced fluorescence of 8 nm thick meso-tetralds (3,5-di-tertiarybutyl-phenyl)porphyrin (H2TBPP) films on ITO with an Ag tip [38]. They reported that the fluorescence was enhanced by the locally confined electromagnetic field in the vicinity of the tip. The enhancement factor is evaluated to be larger than 2000. 

FIG. 12 Simulation of fluorescent decays for dye species located in the aqueous phase following laser pulses in TIR from the water-DCE interface according to Eq. (38). A fast rate constant of excited state decay (10 s ) was assumed in (a). The results showed no difference between infinitely fast or slow kinetics of quenching. On the other hand, a much slower rate of decay can be observed for other sensitizers like Eu and porphyrin species. Under these conditions, heterogeneous quenching associated with the species Q can be readily observed as depicted in (b). (Reprinted with permission from Ref 127. Copyright 1997 American Chemical Society.)... 

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