Fluorescent reporter

As for the previous section, no additional specific NMR data have been published since CHEC(1984) and CHEC-11(1996) NMR data for new substituted compounds are routinely reported. Fluorescent properties of a series of... 

In a series of Calibo 1 glasses ranging in Nd203 concentration from 0.08 to 0.93 mole per cent, they report fluorescent lifetimes ranging from 45 to 38 /xsec. 

HO measurement techniques in the troposphere are the principal focus of this chapter. All reported fluorescence measurements of HO in the troposphere have used lasers. Most of the early tropospheric laser fluorescence work used a frequency-doubled Nd.YAG laser to pump a Rh6G dye laser that was also frequency-doubled and tuned to either the Px( 1) line or the QiU + R23 line group of the A2 v = l X2 v" = 0 band of HO at 282 nm. Fluorescence is detected from the A2X v = 0 —> X2 v" = 0 band at 309 nm. Although the three groups to report tropospheric HO data by this method have often used similar lasers and have usually pumped the same transitions, the air sampling configurations have been quite different. 

Time-resolved fluorescence was used to detect rhodamine 6G (R6G), sulfor-hodamine 101 (SR101), and rhodamine B (RB). A Ti-sapphire laser (800 nm, 50 fs) was used, but the excitation wavelength has been converted to 400 nm (for R6G) or 532 nm (for SR 101 or RB) by an optical parametric amplifier or by second harmonic generation [676], In another report, fluorescence burst detection was used for detection of single chromophore molecules [677]. 

The X-ray crystal structures of pyrazine V.JV -dioxide (134) <02AX(E)1253>, the P-polymorph of phenazine (135) <02AX(C)181>, cobalt(III) complexes of pyrazine-2,6- and pyridine-2,6-dicarboxylic acids <02JIC458>, and bis-urea-substituted phenazines <02ZN(B)937> were reported. Fluorescent pyrido[l,2-a]quinoxalines 136 prepared as pH indicators were examined by X-ray crystallography <02JCS(P2)181>, as were macrocyclic quinoxaline-bridged porphyrinoids obtained from the condensation of dipyrrolylquinoxalines 137 and 1,8-diaminoanthracene... 

Although a number of studies of the photophysics and photochemistry of non-iV-substituted porphyrins and metalloporphyrins have been reported, there are very few studies of N-alkylporphyrins Lavsillee et al. have reported fluorescence spectra of JV-methylporphyrins and their zinc(II) complexes.3,4 There is no report on the lifetime and its correlation with the structure. Ruorescence data for iV-alkylporphyrins and their zinc(II) complexes in degassed acetonitrile are shown in Table 2. 

Excitation spectra may be corrected using a constant response thermopile, a chemical actinometer, a standardized phototube, or a reference compound. The latter two methods also may be used for correcting emission spectra. By reporting fluorescence intensities in relation to reference compounds, one guards against the source and photomultiplier aging characteristics of a given instrument. Any stable fluorescent compound with broad excitation and emission bands is suitable for this purpose. 

The relative solubility of inorganic salts can be used to prepare more complex structures by such methods and examples indude CdS/ZnS [24], CdSe/AgS [25] HgS/CdS [26], PbS/CdS [27, 28], CdS/HgS [29], ZnS/CdSe [30] and ZnSe/CdSe [31] particles. The main constraints on the production of such structures involve the relative solubility of the solids and lattice mismatches between the phases. The preparation of quantum dot quantum well systems such as CdS/HgS/CdS [32, 33], has also been reported, in which a HgS quantum well of 1-3 monolayers is capped by 1-5 monolayers of CdS. The synthesis grows less soluble HgS on CdS (5.2 nm) by ion-replacement. The solubility products of CdS and HgS are 5 X 10 and 1.6 x 10 respectively. The authors reported fluorescence measurements in which the band edge emission for CdS/HgS/CdS is shifted to lower energy values with increasing thickness of the HgS well [33]. 

A review of the published literature for AP -humic interactions reflects variations in fluorescence behavior (8-12,14,15). Sposito and co-workers (11,12) concluded that there was a quenching effect for aluminum ion complexed with a chestnut leaf litter extract (LLE). Philpot et al. (14) also reported fluorescence quenching of humic acid (Aldrich) upon complexation with aluminum. However, unlike these studies, Plankey and Patterson (8-10) found that the fluorescence intensity... 

The first reported fluorescence lifetime of a diazirine has appeared and gives a lifetime for adamantyldiazirine of 240 ps at ambient temperature. A report has... 

A Summary of Previously Reported Fluorescence Characteristics of Uremic Sera"... 

Real-time PCR uses a fluorescently labeled oligonucleotide probe, which eliminates the need for laborious and time-consuming post-PCR processing (e.g., gel electrophoresis). In real-time PCR, a reporter fluorescence dye and a quencher dye are attached to an oligonucleotide probe. Negligible fluorescence from the reporter dye s emission is observed when both dyes... 

The p-anisylmethyl cation 10, generated by dehydration of its corresponding alcohol in TFA-TFE, exhibits absorption and fluorescence maxima of 500 nm and 600 nm, respectively, with a reported fluorescence lifetime of 3 ns [10]. The 1,1-di-p-anisylmethyl cation 11 was generated by protonation of 1,1-di-p-anisylethylene 12 in TFA-TFE. The cation exhibits absorption and fluorescence maxima of 475 nm and 535 nm, respectively, with a fluorescence lifetime of 6 ns [30]. Protonation of 12 in TFA-benzene gave a reported absorption maximum for cation 11 of 500 nm [17],... 

Mixed Alkoxy/Alkyl-PPEs. West (Table 11, entries 5 and 6) reported fluorescence of polymers 2d,m to occur at 449 and 448 nm in solution. Heitz (Table 11, entries 7—10) earlier reported emissions for similar polymers ranging from 438 to 446 nm, carrying methoxy or ethylhexyloxy side chains. These values are in good accord with West s results, while Pang observed for 2b a slightly bathochromically shifted emission at 452 nm with a quantum yield of... 

An increase in reporter fluorescent signal is directly proportional to the number of amplified products generated. 

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