Fluorophore properties

Note that G as derived here relates the FRET-induced sensitized emission in the S channel to the loss of donor emission in the D channel and that it is identical to the correction factor y/ [2] or G [6, 14]. Note however, that if the correction factors or 5 change, G and

correction factor C [3] is a constant that depends only on fluorophore properties and filter settings, and therefore it does not change with excitation intensity or detector gain. This is a clear advantage for confocal filterFRET. C (Eq. (7.14)) and G (Eq. (7.19)) are related as ... 

Barone PW, Parker RS, Strano MS. In vivo fluorescence detection of glucose using a single-walled carbon nanotube optical sensor design, fluorophore properties, advantages, and disadvantages. Analytical Chemistry 2005, 77, 7556-7562. 

Different types of diagrams influenced by differences in fluorophore properties as well as diagrams of high order in comparison to absorbance quotient diagrams are discussed in detail elsewhere [92]. 

BA is challenging in that it displays poor chromophore and fluorophore properties. A similar situation exists with AA because very few of them have a chromophoric moiety that allows for facile detection after separation consequently, derivatization procedures to facilitate their detection are usually required. Fortunately, the presence of common functional groups (amine and carboxylic acid) chemical handles for derivatization schemes that render the BA and AA amenable to spectrophotometric and fluorimetric detection after separation. 

Nitroxides have the property of quenching fluorescence. Thus radical trapping with nitroxides containing fluorophores (e.g. 114) can be monitored by observing the appearance of fluorescence.511015 The method is highly sensitive and has been applied to quantitatively determine radical yields in PLP experiments (Section... 

Membrane depolarization can be measured by members of a class of fluorophores (commonly referred to as the carbocyanine dyes) which have been designed to partition into the membrane, where their orientation and spectral properties change with changes in the electrochemical gradient across the membrane (18). 3,3 -dipropyl-... 

This chapter presents new information about the physical properties of humic acid fractions from the Okefenokee Swamp, Georgia. Specialized techniques of fluorescence depolarization spectroscopy and phase-shift fluorometry allow the nondestructive determination of molar volume and shape in aqueous solutions. The techniques also provide sufficient data to make a reliable estimate of the number of different fluorophores in the molecule their respective excitation and emission spectra, and their phase-resolved emission spectra. These measurements are possible even in instances where two fluorophores have nearly identical emission specta. The general theoretical background of each method is presented first, followed by the specific results of our measurements. Parts of the theoretical treatment of depolarization and phase-shift fluorometry given here are more fully expanded upon in (5,9-ll). Recent work and reviews of these techniques are given by Warner and McGown (72). 

The simplest fluorescence measurement is that of intensity of emission, and most on-line detectors are restricted to this capability. Fluorescence, however, has been used to measure a number of molecular properties. Shifts in the fluorescence spectrum may indicate changes in the hydrophobicity of the fluorophore environment. The lifetime of a fluorescent state is often related to the mobility of the fluorophore. If a polarized light source is used, the emitted light may retain some degree of polarization. If the molecular rotation is far faster than the lifetime of the excited state, all polarization will be lost. If rotation is slow, however, some polarization may be retained. The polarization can be related to the rate of macromolecular tumbling, which, in turn, is related to the molecular size. Time-resolved and polarized fluorescence detectors require special excitation systems and highly sensitive detection systems and have not been commonly adapted for on-line use. 

Nitrogen heterocycles are especially interesting, since they constitute an important class of natural and nonnatural products, many of which exhibit useful optical properties these have been recently synthesized and evaluated as probes in bioassays purposes 141 —441. Despite the diversity of these compounds, benzoxadiazole, acridone, and acridine fluorophores were chosen as a focus in biolabeling applications. 

Agiamamioti and co-workers [72] synthesized a novel biotinylated fluorophore, 10-(2-biotinyloxyethyl)-9-acridone 25 with favorable properties for bioanalytical applications. In aqueous solutions, it displayed high fluorescence ([Pg.37]

The number of new NIR fluorophores that can be used in biological systems has grown substantially in recent years as a consequence of extensive research efforts to improve the properties of available dyes. A brief overview of the various types of long-wavelength (above 600 nm) fluorophores including phycobiliproteins, BODIPY, and Alexa Fluor dyes (Life Technologies), Cy dyes (GE Healthcare),... 

Keywords Combinatorial approach Design-based approach Organic fluorophores Photophysical property Tunability... 

Based on the preliminary understanding of ICT mechanism of coumarin core skeleton, the first systematic application of combinatorial approach toward the field of fluorescence chemistry was reported by Bauerle and co-workers in 2001 [44]. In their study, the structure-photophysical property relationships (SPR) of coumarin fluorophore were revealed by means of a combinatorial approach. 

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