Fluorescence 3-cyclodextrin

Corradini R, Paganuzzi C, Marchelli R et al (2003) Design and synthesis of fluorescent (3-cyclodextrins for the enantioselective sensing of a-amino acids. Chirality 15 S30-S39... 

Cyclodextrins (Sect. 2.2), have the ability to include various organic molecules in their central cavities. Chromophores have been finked to cyclodextrins to build spectroscopic sensors for organic molecules. Many fluorescent cyclodextrins have been prepared to be used as molecular sensors in solution. 

Fluorescent Cyclodextrins for Detecting Organic Compound with Molecular Recognition... 

A. Ueno, Fluorescent sensors and color-change indicators for molecules, Adv. Materials, 1993, 5, 132—134 A. Ueno, Fluorescent cyclodextrins for molecular sensing, Supratnol. Set, 3, 31-36 T. Aoyagi, A. Nakamura, H. Ikeda, T. Ikeda, H. Mihara, A. Ueno, Alizarin yellow-modified jS-cyclodextrin as a guest-responsive absorption change sensor. Anal. Chem., 1997, 69, 659-663. 

Ikeda. H. Nakamura, M. Ise, N. Oguma. N. Nakamura, A. Ikeda, T. Toda, F. Ueno, A. Fluorescent cyclodextrins for molecule sensing Fluorescent properties. NMR characterization. and inclusion phenomena of N-dansylleucine-modified cyclodextrins. J. Am. Chem. Soc. 1996,118 (45). 10980-10988. 

Uenc, A. Ikeda, A. Ikeda. H. Ikeda, T. Toda, F. Fluorescent cyclodextrins responsive to molecules and metal ions. Fluorescence properties and inclusion phenomena of A7 -dansyl-L-lysine-) -cyclodextrin and mon-ensin-incorporated A7 -dansyl-L-lysine- 8-cyclodextrin. J. Org. Chem. 1999. 64 (2). 382 - 387. 

Fig. 3 (a) Fluorescent cyclodextrins used for enantioselective sensing of amino adds (b) enhancement of fluorescence by addition of proline to Cu((S)-l) (reprinted with permission from Elsevier from [87]) (c) quenching of fluorescence by addition of Cu(AA>2 to the free cyclodextrin (S)-l in box A the signal is strongly dependent on the concentration of Cu(AA)2 and in box B it is mainly dependent on the stereochemistry of the analyte, (reprinted from [90] with permission by the Royal Society of Chemistry)... 

Fig. 4 (a) Enantioselective analysis of valine performed using (S)-2 in 2 min time in a microplate reader (b) calibration curve of enantiomeric composition obtained for valine using cyclodextrin (S)-2 (a,b [90]. Reproduced by permission of The Royal Society of Chemistry) (c) analytes (5-10) enantiomerically discriminated using fluorescent cyclodextrins in this type of analysis (d) calibration curve obtained for the 2-aminocaprolactam using cyclodextrin (S)-2 (from [91] with kind permission from Springer Science + Business)... 

Tanabe T, Touma K, Hamasaki K et al (2001) Immobilized fluorescent cyclodextrin on a cellulose membrane as a chmnosensor for molecule detection. Anal Chem 73 3126-3130... 

A. Ueno, Review Fluorescent cyclodextrins for molecule sensing, Supramolecular Science, 3 (1-3), 31-36,1996. 

A. Ueno, Fluorescent Cyclodextrins for Detecting Organic Compounds with Molecular Recognition, In A. W. Czarnick (Ed.), Fluorescent chemosensors for ion and molecule recognition ACS, 1993, pp. 74-84. 

Sodiiun dodecylsulfate, cetyltrimethylam-monium chloride, sodium cholate, -cyclodextrin dansylated amino acids and polycyclic aromatic hydrocarbons > 45-fold 1% in water the greatest enhancement of fluorescence is that of sodium cholate on pyrene [263]... 

A stereoselective determination of enantiomers of 5, its A -oxide and N-desmethyl metabolites in human urine was developed by capillary electrophoresis using laser-induced fluorescence detection and sulfonated /1-cyclodextrin in the running buffer (01JC(B)169). 

Solid-surface room-temperature phosphorescence (RTF) is a relatively new technique which has been used for organic trace analysis in several fields. However, the fundamental interactions needed for RTF are only partly understood. To clarify some of the interactions required for strong RTF, organic compounds adsorbed on several surfaces are being studied. Fluorescence quantum yield values, phosphorescence quantum yield values, and phosphorescence lifetime values were obtained for model compounds adsorbed on sodiiun acetate-sodium chloride mixtures and on a-cyclodextrin-sodium chloride mixtures. With the data obtained, the triplet formation efficiency and some of the rate constants related to the luminescence processes were calculated. This information clarified several of the interactions responsible for RTF from organic compounds adsorbed on sodium acetate-sodium chloride and a-cyclodextrin-sodium chloride mixtures. Work with silica gel chromatoplates has involved studying the effects of moisture, gases, and various solvents on the fluorescence and phosphorescence intensities. The net result of the study has been to improve the experimental conditions for enhanced sensitivity and selectivity in solid-surface luminescence analysis. 

Solid-surface luminescence analysis involves the measurement of fluorescence and phosphorescence of organic compounds adsorbed on solid materials. Several solid matrices such as filter paper, silica with a polyacrylate binder, sodium acetate, and cyclodextrins have been used in trace organic analysis. Recent monographs have considered the details of solid-surface luminescence analysis (1,2). Solid-surface room-temperature fluorescence (RTF) has been used for several years in organic trace analysis. However, solid-surface room-temperature phosphorescence (RTF) is a relatively new technique, and the experimental conditions for RTF are more critical than for RTF. 

Figure 3. Three-dimensional plot of the room-temperature fluorescence of a mixture of 500 ng each of benzo(a)pyrene and benzo(e)pyrene on 80% q-cyclodextrin-NaCl. Numbers along dashed lines show the approximate wavelengths (nm) represented by these lines. The excitation wavelength was varied from 250 nm (front spectrum) to 370 nm (back spectrum) at 2-nm increments. Benzo(a)pyrene emitted from approximately 380 nm to 540 nm, and benzo(e)pyrene emitted from 365 nm to 505 nm.

Multidimensional Fluorescence Analysis of Cyclodextrin Solvent—Extraction Systems... 

Cyclodextrins can solubilize hydrophobic molecules in aqueous media through complex formation (5-8). A nonpolar species prefers the protective environment of the CDx cavity to the hulk aqueous solvent. In addition, cyclodextrins create a degree of structural rigidity and molecular organization for the included species. As a result of these characteristics, these macrocycles are used in studies of fluorescence and phosphorescence enhancement (9-11), stereoselective catalysis (.12,13), and reverse-phase chromatographic separations of structurally similar molecules (14,15). These same complexing abilities make cyclodextrins useful in solvent extraction. 

The data were collected using fluorescence measurements, which allow both identification and quantitation of the fluorophore in solvent extraction. Important experimental considerations such as solvent choice, temperature, and concentrations of the modifier and the analytes are discussed. The utility of this method as a means of simplifying complex PAH mixtures is also evaluated. In addition, the coupling of cyclodextrin-modified solvent extraction with luminescence measurements for qualitative evaluation of components in mixtures will be discussed briefly. 

Dendritic hosts can be used in aqueous solution to encapsulate water-soluble fluorescent probes. Changes in the photophysical properties of these encapsulated probes are useful to understand the properties of the microenvironment created by the dendritic interior. For example, adamantyl-terminated poly(pro-pylene amine) dendrimers from the first to the fifth generation (36 represents the third generation) can be dissolved in water at pH<7 in the presence of -cyclodextrin because of encapsulation of the hydrophobic adamantyl residue inside the /1-cyclodextrin cavity and the presence of protonated tertiary amine units inside the dendrimer [72]. Under these experimental conditions, 8-anifi-... 

The formation of complexes of the fluorescent tracer dye ammonium 1-phenyl-aminonaphthalene-8-sulphonate (10.41) with cyclodextrins has been investigated with favourable results, especially in environmental studies [33]. The ability of this dye to complex with cyclodextrins has been exploited mainly as an analytical tool in the study of cyclodextrin applications, since its fluorescence is easily measured. The interaction of a-, P-and y-cyclodextrins with azo acid dyes containing alkyl chains of different lengths has been reported [36,37]. The formation and isolation of solid complexes between P-cyclodextrin and Cl Acid Red 42, Cl Acid Blue 40 or Erionyl Bordeaux 5BLF (Ciba) have been reported [29]. 

Al-Hassan KA, Khanfer MF (1998) Fluorescence probes for cyclodextrin interiors. J Fluor-esc 8(2) 139-152... 

Hossain, M. A., Mihara, H. and Ueno, A. (2003). Novel peptides bearing pyrene and coumarin units with or without beta-cyclodextrin in their side chains exhibit intramolecular fluorescence resonance energy transfer. J. Am. Chem. Soc. 125, 11178-11179. 

The same authors studied the CL of 4,4,-[oxalylbis(trifluoromethylsulfo-nyl)imino]to[4-methylmorphilinium trifluoromethane sulfonate] (METQ) with hydrogen peroxide and a fluorophor in the presence of a, p, y, and heptakis 2,6-di-O-methyl P-cyclodextrin [66], The fluorophors studied were rhodamine B (RH B), 8-aniline-l-naphthalene sulfonic acid (ANS), potassium 2-p-toluidinylnaph-thalene-6-sulfonate (TNS), and fluorescein. It was found that TNS, ANS, and fluorescein show CL intensity enhancement in all cyclodextrins, while the CL of rhodamine B is enhanced in a- and y-cyclodextrin and reduced in P-cyclodextrin medium. The enhancement factors were found in the range of 1.4 for rhodamine B in a-cyclodextrin and 300 for TNS in heptakis 2,6-di-O-methyl P-cyclodextrin. The authors conclude that this enhancement could be attributed to increases in reaction rate, excitation efficiency, and fluorescence efficiency of the emitting species. Inclusion of a reaction intermediate and fluorophore in the cyclodextrin cavity is proposed as one possible mechanism for the observed enhancement. 

---