Fluorescent complexes

Aluminium chloride forms, for example, fluorescent complexes with flavonoids ... 

Hydroxyquinoline forms colored and fluorescent complexes with numerous metal cations. 

Fluorimetry is generally used if there is no colorimetric method sufficiently sensitive or selective for the substance to be determined. In inorganic analysis the most frequent applications are for the determination of metal ions as fluorescent organic complexes. Many of the complexes of oxine fluoresce strongly aluminium, zinc, magnesium, and gallium are sometimes determined at low concentrations by this method. Aluminium forms fluorescent complexes with the dyestuff eriochrome blue black RC (pontachrome blue black R), whilst beryllium forms a fluorescent complex with quinizarin. 

Fluorescent complexes for biomedical applications (S. Faulkner, J. Matthews)... 

Rye, H. S, Yue, S, Wemmer, D. E, Quesada, M. A, Haugland, R. P, Mathies, R. A. and Glazer, A. N. (1992). Stable fluorescent complexes of double-stranded DNA with bis-intercalating asymmetric cyanine dyes -Properties and applications. Nucleic Acids Res. 20, 2803-2812. 

Four forms of amine-reactive rhodamine probes are commonly available. Two of them are based on the tetramethyl derivatives of the fundamental rhodamine structure, one is based on the sulforhodamine B or Lissamine derivative, and the last is the sulforhodamine 101 or Texas Red-type of derivative. All of them react under alkaline conditions with primary amines in proteins and other molecules to form stable, highly fluorescent complexes. 

The natural fluorescence of CTC and its derivatives has been used extensively to determine small amounts of CTC in biological materials. Kohn (86) showed that the fluorescent complex formed by CTC with calcium ions and barbital could be extracted from animal tissues into an organic solvent and then measured spectrofluorometrically. The intense fluorescence of anhydro-CTC was used by Hayes and DuBuy (87) to determine CTC in animal tissues, tissue culture cells, and bacteria. Poiger and Schlatter (88) extracted CTC from biological material into ethyl acetate as the CTC-calcium trichloroacetate ion pair. The fluorescence of the antibiotic was then enhanced by the addition of magnesium ions and a base. 

The reaction of neomycin with fluorescamine to form a fluorescent complex has been reported by Kusnir Barna The fluorescence intensity varies with both the pH of the solution (optimum pH range 7.5-9.5) and the amount of fluorescamine added. This procedure may be used to determine neomycin at very low levels, the minimum concentration determinable being 45 ng/ml. 

Fig. 20a. 6. Response curve of a Ru-fluorescence complex based oxygen optical sensor to oxygen in gas mixture. Courtesy of Ocean Optics, Inc.

Bishop JA (1963) Complex formation and fluorescence complexes of 8-hydroxyquinoline-5-sulfonic acid. Anal Chim Acta 29 172-177... 

The cyanine dye dimethylindole red (DIR), with significantly reduced affinity for double-stranded DNA and nonspecific RNA, was used to generate a fluorescent complex (fluoromodule) with high affinity RNA aptamers (Fig. 12) [8]. DIR has... 

Formation of a fluorescent complex is the basis of most methods of ion and molecule recognition (see Chapter 9). 

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