Exploring Aqueous Solution Dynamics of an Amphiphilic Diblock Copolymer: Dielectric Relaxation and Time-Resolved Fluorescence Measurements

2019 ◽  
Vol 123 (27) ◽  
pp. 5892-5901 ◽  
Author(s):  
Ejaj Tarif ◽  
Biswajit Saha ◽  
Kallol Mukherjee ◽  
Priyadarsi De ◽  
Ranjit Biswas
Keyword(s):  
Aqueous Solution ◽  
Dielectric Relaxation ◽  
Diblock Copolymer ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Amphiphilic Diblock Copolymer ◽  
Fluorescence Measurements ◽  
Solution Dynamics

Time-Resolved Fluorescence Studies of Hematoporphyrin in Different Solvent Systems

1983 ◽  
Vol 38 (1-2) ◽  
pp. 83-89 ◽  
Author(s):  
A. Andreoni ◽  
R. Cubeddu ◽  
S. De Silvestri ◽  
G. Jori ◽  
P. Laporta ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Organic Solvents ◽  
Slow Component ◽  
Fluorescence Decay ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Fluorescence Studies ◽  
Fluorescence Measurements ◽  
Dimeric Form ◽  
Solvent Systems

Time-resolved fluorescence studies of hematoporphyrin in aqueous solution and in different organic solvents are presented. The| observation of two exponential components in the fluorescence decay in aqueous solution reveals the presence of a monomeric and aggregated (probably dimeric) form of the molecule, as confirmed by absorption and fluorescence measurements. The slow component (~ 15 ns in aqueous solution) and the fast one (~ 3.8 ns in aqueous solution) are attributed to monomers and dimers, respectively. Higher aggregated species of hematoporphyrin are also present, which are essentially devoid of fluorescence properties.

Sensitive, rapid procedure for time-resolved immunofluorometry of lutropin.

1988 ◽  
Vol 34 (8) ◽  
pp. 1640-1644 ◽  
Author(s):  
M J Khosravi ◽  
R C Morton ◽  
E P Diamandis
Keyword(s):  
Monoclonal Antibody ◽  
Solid Phase ◽  
Detection System ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Practical Procedure ◽  
Daily Monitoring ◽  
Fluorescence Measurements ◽  
Capture Antibody ◽  
Europium Chelate

Abstract In this new immunofluorometric method for quantification of lutropin in serum, the "sandwich" principle is combined with time-resolved fluorescence measurements, with the europium chelate 4,7-bis(chlorosulfophenyl)-1,10-phenanthroline-2,9-dicarboxylic acid (BCPDA) used as label. A monoclonal antibody to the alpha-subunit of lutropin is adsorbed onto the walls of white-opaque microtiter wells to form the solid-phase capture antibody, and a biotin-labeled soluble monoclonal antibody is used for antigen quantification. The detection system is completed with streptavidin, which has been linked to a protein bulking agent labeled with multiple BCPDA residues. In the presence of excess europium, the fluorescence of the final complex attached to captured lutropin molecules is measured on the dried solid phasse with an automated time-resolved fluorometer. The assay can be performed as a rapid (less than 60 min incubation) or regular (150 min incubation) procedure. The rapid assay is well-suited for routine daily monitoring of increasing or ovulatory lutropin concentrations; the regular assay, with its greater sensitivity (0.5 int. unit/L), is a practical procedure for lutropin measurements in hyposecretory states. The assay measures up to 240 int. units/L, and results compare well with those by a commercially available radioimmunoassay, an immunoradiometric assay, and another time-resolved immunofluorometric procedure.

Local Environment of Surface-Polyelectrolyte-Bound DNA Oligomers

2000 ◽  
Vol 651 ◽  
Author(s):  
Sangmin Jeon ◽  
Sung Chul Bae ◽  
Jiang John Zhao ◽  
Steve Granick
Keyword(s):  
Aqueous Solution ◽  
Salt Concentration ◽  
Fluorescence Anisotropy ◽  
Local Environment ◽  
Time Resolved Fluorescence ◽  
Surface Complexes ◽  
Dna Oligomers ◽  
Time Resolved ◽  
Two Photon ◽  
Anisotropy Decay

AbstractTwo-photon time-resolved fluorescence anisotropy methods were used to study the dynamical environment when fluorescent-labelled DNA oligomers (labelled with FAM, 6-fluorescein-6-carboxamido hexanoate) formed surface complexes with quaternized polyvinylpyridine (QPVP) cationic layers on a glass surface. We compared the anisotropy decay of DNA in bulk aqueous solution, DNA adsorbed onto QPVP, and QPVP-DNA-QPVP sandwich structures. When DNA was adsorbed onto QPVP, its anisotropy decay was dramatically retarded compared to the bulk, which means it had very slow rotational motion on the surface. Motions slowed down with increasing salt concentration up to a level of 0.1 M NaCl, but mobility began to increase at still higher salt concentration owing to detachment from the surface-immobilizing QPVP layers.

Nanosecond dynamics of horse heart apocytochrome c in aqueous solution as studied by time-resolved fluorescence of the single tryptophan residue (Trp-59)

Biochemistry ◽  
1988 ◽  
Vol 27 (24) ◽  
pp. 8752-8761 ◽  
Author(s):  
Michel Vincent ◽  
Jean Claude Brochon ◽  
Fabienne Merola ◽  
Wilco Jordi ◽  
Jacques Gallay
Keyword(s):  
Aqueous Solution ◽  
Tryptophan Residue ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Apocytochrome C ◽  
Nanosecond Dynamics

scholarly journals Development, Characterization, and Application of a Versatile Single Particle Detection Apparatus for Time-Integrated and Time-Resolved Fluorescence Measurements—Part II: Experimental Evaluation

2009 ◽  
Vol 2009 ◽  
pp. 1-14
Author(s):  
Xihong Wu ◽  
J. A. Merten ◽  
N. Omenetto ◽  
B. W. Smith ◽  
J. D. Winefordner
Keyword(s):  
Single Particle ◽  
Narrow Beam ◽  
Time Resolved Fluorescence ◽  
Particle Detection ◽  
Time Resolved ◽  
Endogenous Fluorophores ◽  
Fluorescence Measurements ◽  
On Line ◽  
Single Particle Detection ◽  
Speed Mode

This paper describes the experimental realization and characterization of a versatile single particle detection apparatus. The system utilizes a novel particle beam inlet that can serve as either an on-line particle concentrator (i.e., all diameters confined in a narrow beam) or as a segregator (i.e., selected diameters confined in a narrow beam) and can be operated in a high-speed mode as well as in a low-speed mode, thus allowing different interaction times between the particles and the laser beam. An aerodynamic sizing technique has been incorporated into the system to provide rapid, real-time, and high-resolution sizing. Parameters such as transmission efficiency and size-segregation efficiency have been measured. The performance of the instrument has been demonstrated by on-line detection of spectrally resolved and time resolved fluorescence detection from airborne dye-doped particles and aerosolized endogenous fluorophores found in biological agents.

Fluorescence property of photosystem II protein complexes bound to a gold nanoparticle

2017 ◽  
Vol 198 ◽  
pp. 121-134 ◽  
Author(s):  
Kazuki Tahara ◽  
Ahmed Mohamed ◽  
Kousuke Kawahara ◽  
Ryo Nagao ◽  
Yuki Kato ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Gold Nanoparticle ◽  
Water Oxidation ◽  
Artificial Photosynthesis ◽  
Fluorescence Property ◽  
Light Illumination ◽  
Time Resolved Fluorescence ◽  
Strong Light ◽  
Time Resolved ◽  
Fluorescence Measurements

Development of an efficient photo-anode system for water oxidation is key to the success of artificial photosynthesis. We previously assembled photosystem II (PSII) proteins, which are an efficient natural photocatalyst for water oxidation, on a gold nanoparticle (GNP) to prepare a PSII–GNP conjugate as an anode system in a light-driven water-splitting nano-device (Noji et al., J. Phys. Chem. Lett., 2011, 2, 2448–2452). In the current study, we characterized the fluorescence property of the PSII–GNP conjugate by static and time-resolved fluorescence measurements, and compared with that of free PSII proteins. It was shown that in a static fluorescence spectrum measured at 77 K, the amplitude of a major peak at 683 nm was significantly reduced and a red shoulder at 693 nm disappeared in PSII–GNP. Time-resolved fluorescence measurements showed that picosecond components at 683 nm decayed faster by factors of 1.4–2.1 in PSII–GNP than in free PSII, explaining the observed quenching of the major fluorescence peak. In addition, a nanosecond-decay component arising from a ‘red chlorophyll’ at 693 nm was lost in time-resolved fluorescence of PSII–GNP, probably due to a structural perturbation of this chlorophyll by interaction with GNP. Consistently with these fluorescence properties, degradation of PSII during strong-light illumination was two times slower in PSII–GNP than in free PSII. The enhanced durability of PSII is an advantageous property of the PSII–GNP conjugate in the development of an artificial photosynthesis device.

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