Measuring the Hydrodynamic Radius of Quantum Dots by Fluorescence Correlation Spectroscopy

2014 ◽  
pp. 85-91 ◽  
Author(s):  
André A. de Thomaz ◽  
Diogo B. Almeida ◽  
Carlos L. Cesar
Keyword(s):  
Quantum Dots ◽  
Fluorescence Correlation Spectroscopy ◽  
Hydrodynamic Radius ◽  
Correlation Spectroscopy ◽  
Fluorescence Correlation

Measurement of the Hydrodynamic Radius of Quantum Dots by Fluorescence Correlation Spectroscopy Excluding Blinking

2015 ◽  
Vol 119 (11) ◽  
pp. 4294-4299 ◽  
Author(s):  
A. A. de Thomaz ◽  
D. B. Almeida ◽  
V. B. Pelegati ◽  
H. F. Carvalho ◽  
C. L. Cesar
Keyword(s):  
Quantum Dots ◽  
Fluorescence Correlation Spectroscopy ◽  
Hydrodynamic Radius ◽  
Correlation Spectroscopy ◽  
Fluorescence Correlation

Size determination of quantum dots with fluorescence correlation spectroscopy

2011 ◽  
Author(s):  
D. Hill ◽  
C. Ast ◽  
H.-G. Löhmannsröben ◽  
A. Zulqurnain ◽  
W. Parak ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Fluorescence Correlation Spectroscopy ◽  
Correlation Spectroscopy ◽  
Size Determination ◽  
Fluorescence Correlation

scholarly journals Development of a fluorescence correlation spectroscopy instrument and its application in sizing quantum dot nanoparticles

2015 ◽  
Vol 25 (1) ◽  
pp. 59 ◽  
Author(s):  
Nguyen Thi Thanh Bao ◽  
Dinh Van Trung
Keyword(s):  
Quantum Dots ◽  
Fluorescence Correlation Spectroscopy ◽  
Dynamic Properties ◽  
Correlation Spectroscopy ◽  
Fluorescence Signal ◽  
Fluorescence Correlation ◽  
Statistical Fluctuations ◽  
Measurement Results ◽  
Particle Level ◽  
Microscope Imaging

Fluorescence correlation spectroscopy is a relatively new technique to measure and quantify the statistical fluctuations of the fluorescence signal from the measurement volume. Combining with sensitive detection method and confocal microscopy, the FCS technique has become a powerful tool in studying the dynamic properties of nanoparticles at single particle level. In this paper we present the construction of a highly sensitive FCS instrument and the measurement results from a sample of semiconductor quantum dots. We provide the analysis procedure for determining the hydrodynamic radius of the quantum dots and compare the results with that obtained directly from electron microscope imaging. The good agreement indicates the reliability of the FCS technique and open the way for further applications of this technique in studying nanoparticles.

scholarly journals Characterization of protein adsorption onto FePt nanoparticles using dual-focus fluorescence correlation spectroscopy

2011 ◽  
Vol 2 ◽  
pp. 374-383 ◽  
Author(s):  
Pauline Maffre ◽  
Karin Nienhaus ◽  
Faheem Amin ◽  
Wolfgang J Parak ◽  
G Ulrich Nienhaus
Keyword(s):  
Fluorescence Correlation Spectroscopy ◽  
Hydrodynamic Radius ◽  
Serum Proteins ◽  
Correlation Spectroscopy ◽  
Fept Nanoparticles ◽  
Absolute Increase ◽  
Fluorescence Correlation ◽  
X Ray Crystallography ◽  
Blood Serum Proteins ◽  
Equilibrium Dissociation

Using dual-focus fluorescence correlation spectroscopy, we have analyzed the adsorption of three human blood serum proteins, namely serum albumin, apolipoprotein A-I and apolipoprotein E4, onto polymer-coated, fluorescently labeled FePt nanoparticles (~12 nm diameter) carrying negatively charged carboxyl groups on their surface. For all three proteins, a step-wise increase in hydrodynamic radius with protein concentration was observed, strongly suggesting the formation of protein monolayers that enclose the nanoparticles. Consistent with this interpretation, the absolute increase in hydrodynamic radius can be correlated with the molecular shapes of the proteins known from X-ray crystallography and solution experiments, indicating that the proteins bind on the nanoparticles in specific orientations. The equilibrium dissociation coefficients, measuring the affinity of the proteins to the nanoparticles, were observed to differ by almost four orders of magnitude. These variations can be understood in terms of the electrostatic properties of the proteins. From structure-based calculations of the surface potentials, positively charged patches of different extents can be revealed, through which the proteins interact electrostatically with the negatively charged nanoparticle surfaces.

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