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.

Optical single-particle detection in nanoholes towards simple parallel detection of molecular binding events

2012 ◽  
Vol 93 (2) ◽  
pp. 140-151 ◽  
Author(s):  
Norbert Jahr ◽  
Nicole Hädrich ◽  
Mamuna Anwar ◽  
Andrea Csaki ◽  
Ondra Stranik ◽  
...  
Keyword(s):  
Single Particle ◽  
Particle Detection ◽  
Molecular Binding ◽  
Parallel Detection ◽  
Single Particle Detection

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.

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.

scholarly journals Modelling of Evanescent Field Scattering

Proceedings ◽  
2020 ◽  
Vol 56 (1) ◽  
pp. 16
Author(s):  
Andreas Tortschanoff ◽  
Marcus Baumgart ◽  
Jaka Pribošek
Keyword(s):  
Numerical Analysis ◽  
Single Particle ◽  
Evanescent Field ◽  
Promising Method ◽  
Analytical Models ◽  
Particle Scattering ◽  
Particle Detection ◽  
Sensing Mechanism ◽  
Single Particle Detection

Evanescent field particle scattering is a promising method for single particle detection. In this study, we performed a detailed numerical analysis to show the possibilities and limitations of analytical models for predicting the capabilities of this sensing mechanism.

Sensitive miniature single-particle immunoassay of prostate-specific antigen using time-resolved fluorescence

2003 ◽  
Vol 482 (2) ◽  
pp. 157-164 ◽  
Author(s):  
Harri Härmä ◽  
Anne-Maria Pelkkikangas ◽  
Tero Soukka ◽  
Petri Huhtinen ◽  
Saila Huopalahti ◽  
...  
Keyword(s):  
Prostate Specific Antigen ◽  
Single Particle ◽  
Specific Antigen ◽  
Time Resolved Fluorescence ◽  
Time Resolved

An integrated instrumentation for light‐scattering and time‐resolved fluorescence measurements

1995 ◽  
Vol 66 (3) ◽  
pp. 2405-2410 ◽  
Author(s):  
M. Musolino ◽  
R. Cubeddu ◽  
A. Pifferi ◽  
P. Taroni ◽  
P. Lago ◽  
...  
Keyword(s):  
Light Scattering ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Fluorescence Measurements
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