scholarly journals Fluorescence properties of free and protein bound fluorescein dyes. I. Macrospectrofluorometric measurements.

1978 ◽  
Vol 26 (4) ◽  
pp. 277-283 ◽  
Author(s):  
K Schauenstein ◽  
E Schauenstein ◽  
G Wick
Keyword(s):  
Blue Light ◽  
Fluorescence Intensity ◽  
Gamma Globulin ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Sharp Decrease ◽  
Fluorescein Isothiocyanate ◽  
Fluorescence Properties ◽  
Sodium Fluorescein ◽  
Uv Excitation

Excitation and emission properties of fluorescein derivatives were studied macrofluorometrically. Measurements were performed with solutions of various concentrations (0.07-100 microgram/ml) of free sodium fluorescein prepared from fluorescein diacetate (FDA), fluorescein isothiocyanate (FITC) and FITC bound to rabbit gamma-globulin. Both excitation and emission spectra as well as fluorescence intensities at constant excitation/emission wavelengths (496/515 nm) were recorded. The findings indicate that (1) FDA gives about twice the fluorescence intensity compared to equal concentrations of FITC. (2) The fluorescence properties of FITC upon excitation with blue light (lambda = 496 nm) are only slightly altered by the conjugation to rabbit gamma-globulin. (3) Considerable quenching due to conjugation could, however, be shown to occur upon UV excitation (lambda = 340 nm). (4) Fluorescence emission excited by visible blue light (496 nm) increases linearly to dye concentration in a range of 0.07-2.5 microgram/ml. Beginning at 5 microgram/ml (10-(5) M/1) all three compounds show a sharp decrease of fluorescence intensity with further increasing concentration. Practical aspects of these data for the immunofluorescence method are discussed.

A fluorochrome from aniline blue: structure,synthesis and fluorescence properties

1982 ◽  
Vol 35 (12) ◽  
pp. 2571 ◽  
Author(s):  
NA Evans ◽  
PA Hoyne
Keyword(s):  
Critical Micelle Concentration ◽  
Cationic Surfactant ◽  
Fluorescence Intensity ◽  
Fluorescence Emission ◽  
Aniline Blue ◽  
Fluorescence Properties ◽  
Hexadecyltrimethylammonium Bromide ◽  
Commercial Sample ◽  
Emission Maximum ◽  
Structure Synthesis

A fluorochrome has been isolated in analytically pure form from a commercial sample of the triaryl-methane dye aniline blue. Its structure has been shown to be sodium 4,4'-[carbonylbis(benzene-4,1-diyl)bis(imino)]bisbenzenesulfonate by spectroscopic means and confirmed by synthesis. Its fluorescence emission, which is markedly solvent-dependent, is 150 times greater in butan-1-ol than in water (however, the wavelength of the emission maximum is not altered significantly). In the presence of a cationic surfactant, hexadecyltrimethylammonium bromide, the fluorescence intensity reaches a maximum at approximately the critical micelle concentration of the surfactant.

scholarly journals Quantitative fluorescence spectrophotometry of acridine orange-stained unfixed cells. Potential for automated detection of human uterine cancer.

1976 ◽  
Vol 24 (1) ◽  
pp. 315-321 ◽  
Author(s):  
J F Golden ◽  
S S West ◽  
C K Echols ◽  
H M Shingleton
Keyword(s):  
Acridine Orange ◽  
Fluorescence Intensity ◽  
Uterine Cancer ◽  
Female Genital Tract ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Cell Types ◽  
Fluorescence Emission Spectra ◽  
Acid Complex ◽  
Normal Cells

After staining with acridine orange (AO), the nuclei of unfixed cells from the human female genital tract exhibited the same fluorescence behavior previously observed for human and murine leukocytes and mouse ascites tumor cells. With staining conditions chosen to assure saturation of the green-fluorescing AO-nucleic acid complex in normal cells, corrected fluorescence emission spectra were recorded from the entire nucleus of 341 cells taken from 32 normal and 28 abnormal patients. Intensity of the recorded spectra was expressed in phosphor particle units, a fixed arbitrary unit of fluorescence intensity, to display intensity differences among the spectra from the various cell types. In all abnormal samples, one or more cells were found with 530-nm nuclear fluorescence intensity considerably greater than the maximum intensity recorded from normal cells. Determination of the adequacy of 530-nm nuclear fluorescence intensity as a criterion for cancer detection requires additional investigation. Additional criteria, if needed, may be supplied by the metachromasy of AO-stained unfixed cells.

scholarly journals One-Pot Hydrothermal Synthesis of Carbon Dots as Fluorescent Probes for the Determination of Mercuric and Hypochlorite Ions

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1831
Author(s):  
Hsin Lee ◽  
Yen-Chang Su ◽  
Hsiang-Hao Tang ◽  
Yu-Sheng Lee ◽  
Jan-Yee Lee ◽  
...  
Keyword(s):  
Fluorescence Intensity ◽  
Fluorescent Probes ◽  
Carbon Dots ◽  
Limit Of Detection ◽  
Tap Water ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Excitation Wavelength ◽  
One Pot ◽  
Fluorescence Emission Spectra

Nitrogen and sulfur codoped carbon dots (NSCDs) were synthesized via a one-pot hydrothermal method, and citric acid, ethylenediamine, and methyl blue were used as precursors. The obtained NSCDs were spherical with an average size of 1.86 nm. The fluorescence emission spectra of the NSCDs were excitation independent and emitted blue fluorescence at 440 nm with an excitation wavelength at 350 nm. The quantum yield of the NSCDs was calculated to be 68.0%. The NSCDs could be constructed as fluorescent probes for highly selective and sensitive sensing mercuric (Hg2+) and hypochlorite (ClO−) ions. As the addition of Hg2+ or ClO− ions to the NSCDs, the fluorescence intensity was effectively quenched due to dynamic quenching. Under the optimal conditions, the linear response of the fluorescence intensity ranged from 0.7 μM to 15 μM with a detection limit of 0.54 μM and from 0.3 μM to 5.0 μM with a limit of detection of 0.29 μM for Hg2+ and ClO− ions, respectively. Finally, the proposed method was successfully used for quantifying Hg2+ and ClO− ions in spiked tap water samples.

scholarly journals Sponge-derived Ageladine A affects the in vivo fluorescence emission spectra of microalgae

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242464
Author(s):  
Carolin Peter ◽  
Silke Thoms ◽  
Florian Koch ◽  
Franz Josef Sartoris ◽  
Ulf Bickmeyer
Keyword(s):  
Natural Products ◽  
Fluorescence Intensity ◽  
Crucial Role ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Fluorescence Emission Spectra ◽  
Tisochrysis Lutea ◽  
Emission Maximum ◽  
Ph Dependent

In several marine hosts of microalgae, fluorescent natural products may play an important role. While the ecological function of these compounds is not well understood, an interaction of these molecules with the photosynthesis of the symbionts has been suggested. In this study, the effect of Ageladine A (Ag A), a pH-dependent fluorophore found in sponges of the genus Agelas, on microalgal fluorescence was examined. The spectra showed an accumulation of Ag A within the cells, but with variable impacts on fluorescence. While in two Synechococcus strains, fluorescence of phycoerythrin increased significantly, the fluorescence of other Synechococcus strains was not affected. In four out of the five eukaryote species examined, chlorophyll a (Chl a) fluorescence intensity was modulated. In Tisochrysis lutea, for example, the position of the fluorescence emission maximum of Chl a was shifted. The variety of these effects of Ag A on microalgal fluorescence suggests that fluorophores derived from animals could play a crucial role in shaping the composition of marine host/symbiont systems.

Germanium triazatetrabenzcorrole and germanium phthalocyanine: Synthesis, fluorescence and singlet oxygen generation

2018 ◽  
Vol 22 (09n10) ◽  
pp. 847-852 ◽  
Author(s):  
Xian-Fu Zhang ◽  
Xiaojie Sun
Keyword(s):  
Singlet Oxygen ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Fluorescence Properties ◽  
Quantum Yields ◽  
Fluorescence Lifetimes ◽  
Fluorescence Emission Spectra ◽  
Oxygen Generation ◽  
Fluorescence Quantum Yields ◽  
Singlet Oxygen Generation

The synthesis, fluorescence properties and singlet oxygen generation capability of germanium tetrabenzotriazacorrole (LGeTBC), germanium phthalocyanine (Cl[Formula: see text]GePc) and their derivatives are described. Measurements include UV-vis absorption spectra, fluorescence emission spectra, fluorescence quantum yields fluorescence lifetimes, and singlet delta oxygen quantum yields. LGeTBC and its derivatives exhibit quite different spectral and fluorescence properties from their phthalocyanine precursor. Both LGeTBC and Cl[Formula: see text]GePc show high singlet delta oxygen quantum yields and suitable fluorescence quantum yields, indicating that they can act as good singlet oxygen photosensitizers for photodynamic therapy.

scholarly journals QUANTITATIVE FLUORESCENCE MICROSCOPY: FLUORESCENT ANTIBODY AUTOMATIC SCANNING TECHNIQUES

1966 ◽  
Vol 14 (3) ◽  
pp. 260-273 ◽  
Author(s):  
H. P. MANSBERG ◽  
J. KUSNETZ
Keyword(s):  
Fluorescent Antibody ◽  
Spectral Characteristics ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Background Level ◽  
Fluorescein Isothiocyanate ◽  
Image Plane ◽  
Light Sources ◽  
Close Proximity ◽  
Quantitative Fluorescence

The application of microscanning techniques to the detection, classification and counting of fluorescence-tagged microorganisms presents unique and somewhat more severe optical and photometric problems than those encountered in absorption type microscanning. Low fluorescence emission, autofluorescence of optics, filters and specimen mounting media and the close proximity of the excitation and emission wavelengths of typical fluorochromes impose severe limitations on sensitivity and maximum scanning rates. By the use of bright field illumination, liquid dye immersion filters, and careful matching of light source and filter spectral characteristics to those of the fluorochromes, fluorescence output was increased 10-100 times with negligible increase in background level. The effectiveness of a number of light sources filters and phototubes in producing maximal signals from fluorescein isothiocyanate-tagged microorganisms in an experimental fluorescence microscanner are compared. Proper selection produced increases in sensitivity of more than 10 times the initial sensitivity obtained with standard fluorescence microscopes and illuminators. Image plane, object plane and flying spot scanning techniques are compared as to their suitability for fluorescence microscanning. Practical scanner designs are illustrated. A consideration of the advantages of laser excitation of fluorochromes indicates that in addition to greatly simplifying filtering problems, a 102 increase in irradiance can be expected. The possibility of differential diagnosis based upon two color fluorescence discrimination is explored. Overlapping emission spectra presents the major difficulties in such a system. An experimental two color fluorescence microscanner and the optical and electronic techniques employed for the discrimination of overlapping color spectra is described.

Optical Properties and Zinc Nitride Thin Films Prepared Using Magnetron Reactive Sputtering

2014 ◽  
Vol 940 ◽  
pp. 11-15
Author(s):  
Jun Qin Feng ◽  
Jun Fang Chen
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Near Infrared ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Sem Images ◽  
Fluorescence Emission Spectra ◽  
Glass Substrates ◽  
Zinc Nitride ◽  
Direct Band

Zinc nitride films were deposited by ion sources-assisted magnetron sputtering with the use of Zn target (99.99% purity) on 7059 glass substrates. The films were characterized by XRD, SEM and EDS, the results of which show that the polycrystalline zinc nitride thin film can be grown on the glass substrates, the EDS spectrum confirmed the chemical composition of the films and the SEM images revealed that the zinc nitride thin films have a dense structure. Ultraviolet-visible-near infrared spectrophotometer was used to study the transmittance behaviors of zinc nitride thin films, which calculated the optical band gap by Davis Mott model. The results of the fluorescence emission spectra show the zinc nitride would be a direct band gap semiconductor material.

Stress and Phase Transformation Phenomena in Oxide Films: Real-Time Spectroscopic Measurements

1992 ◽  
Vol 271 ◽  
Author(s):  
Gregory J. Exarhos ◽  
Nancy J. Hess
Keyword(s):  
Phase Transformation ◽  
Applied Pressure ◽  
Oxide Films ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Film Deposition ◽  
Optical Methods ◽  
Fluorescence Emission Spectra ◽  
Line Intensities ◽  
Deposition Parameters

ABSTRACTIn situ optical methods are reviewed for characterization of phase transformation processes and evaluation of residual stress in solution-deposited metastable oxide films. Such low density films most often are deposited as disordered phases making them prone to crystallization and attendant densification when subjected to increased temperature and/or applied pressure. Inherent stress imparted during film deposition and its evolution during the transformation are evaluated from phonon frequency shifts seen in Raman spectra (TiO2) or from changes in the laser-induced fluorescence emission spectra for films containing rare earth (Sm+3:Y3Al5O12) or transition metal (Cr+3 :Al2O3) dopants. The data in combination with measured increases in line intensities intrinsic to the evolving phase are used to follow crystallization processes in thin films. In general, film deposition parameters are found to influence the crystallite ingrowth kinetics and the magnitude of stress and stress relaxation in the film during the transformation. The utility of these methods to probe crystallization phenomena in oxide films will be addressed.

scholarly journals Fluorescence emission spectra of silver and silver/cobalt nanoparticles

2012 ◽  
Vol 19 (3) ◽  
pp. 943-947 ◽  
Author(s):  
Z. Parang ◽  
A. Keshavarz ◽  
S. Farahi ◽  
S.M. Elahi ◽  
M. Ghoranneviss ◽  
...  
Keyword(s):  
Fluorescence Emission ◽  
Emission Spectra ◽  
Cobalt Nanoparticles ◽  
Fluorescence Emission Spectra
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