Polarization properties of fluorescent BSA protected Au25 nanoclusters

Sangram Limbaji Raut, Rahul Chib, Ryan Rich, Dmytro Shumilov, Zygmunt Gryczynski, Ignacy Gryczynski

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

BSA protected gold nanoclusters (Au25) are attracting a great deal of attention due to their unique spectroscopic properties and possible use in biophysical applications. Although there are reports on synthetic strategies, spectroscopy and applications, little is known about their polarization behavior. In this study, we synthesized the BSA protected Au25 nanoclusters and studied their steady state and time resolved fluorescence properties including polarization behavior in different solvents: glycerol, propylene glycol and water. We demonstrated that the nanocluster absorption spectrum can be separated from the extinction spectrum by subtraction of Rayleigh scattering. The nanocluster absorption spectrum is well approximated by three Gaussian components. By a comparison of the emissions from BSA Au 25 clusters and rhodamine B in water, we estimated the quantum yield of nanoclusters to be higher than 0.06. The fluorescence lifetime of BSA Au 25 clusters is long and heterogeneous with an average value of 1.84 μs. In glycerol at -20°C the anisotropy is high, reaching a value of 0.35. However, the excitation anisotropy strongly depends on the excitation wavelengths indicating a significant overlap of the different transition moments. The anisotropy decay in water reveals a correlation time below 0.2 μs. In propylene glycol the measured correlation time is longer and the initial anisotropy depends on the excitation wavelength. BSA Au25 clusters, due to long lifetime and high polarization, can potentially be used in studying large macromolecules such as protein complexes with large molecular weight.

Original languageEnglish
Pages (from-to)3441-3446
Number of pages6
JournalNanoscale
Volume5
Issue number8
DOIs
StatePublished - 21 Apr 2013

Fingerprint

Nanoclusters
Polarization
Anisotropy
Propylene Glycol
rhodamine B
Glycols
Glycerol
Propylene
Water
Absorption spectra
Fluorescence
Wavelength
Rayleigh scattering
Quantum yield
Macromolecules
Gold
Molecular weight
Spectroscopy
Proteins

Cite this

Raut, Sangram Limbaji ; Chib, Rahul ; Rich, Ryan ; Shumilov, Dmytro ; Gryczynski, Zygmunt ; Gryczynski, Ignacy. / Polarization properties of fluorescent BSA protected Au25 nanoclusters. In: Nanoscale. 2013 ; Vol. 5, No. 8. pp. 3441-3446.
@article{1c559ad23cf143bdaa2f72868a44b40a,
title = "Polarization properties of fluorescent BSA protected Au25 nanoclusters",
abstract = "BSA protected gold nanoclusters (Au25) are attracting a great deal of attention due to their unique spectroscopic properties and possible use in biophysical applications. Although there are reports on synthetic strategies, spectroscopy and applications, little is known about their polarization behavior. In this study, we synthesized the BSA protected Au25 nanoclusters and studied their steady state and time resolved fluorescence properties including polarization behavior in different solvents: glycerol, propylene glycol and water. We demonstrated that the nanocluster absorption spectrum can be separated from the extinction spectrum by subtraction of Rayleigh scattering. The nanocluster absorption spectrum is well approximated by three Gaussian components. By a comparison of the emissions from BSA Au 25 clusters and rhodamine B in water, we estimated the quantum yield of nanoclusters to be higher than 0.06. The fluorescence lifetime of BSA Au 25 clusters is long and heterogeneous with an average value of 1.84 μs. In glycerol at -20°C the anisotropy is high, reaching a value of 0.35. However, the excitation anisotropy strongly depends on the excitation wavelengths indicating a significant overlap of the different transition moments. The anisotropy decay in water reveals a correlation time below 0.2 μs. In propylene glycol the measured correlation time is longer and the initial anisotropy depends on the excitation wavelength. BSA Au25 clusters, due to long lifetime and high polarization, can potentially be used in studying large macromolecules such as protein complexes with large molecular weight.",
author = "Raut, {Sangram Limbaji} and Rahul Chib and Ryan Rich and Dmytro Shumilov and Zygmunt Gryczynski and Ignacy Gryczynski",
year = "2013",
month = "4",
day = "21",
doi = "10.1039/c3nr34152f",
language = "English",
volume = "5",
pages = "3441--3446",
journal = "Nanoscale",
issn = "2040-3364",
publisher = "Royal Society of Chemistry",
number = "8",

}

Polarization properties of fluorescent BSA protected Au25 nanoclusters. / Raut, Sangram Limbaji; Chib, Rahul; Rich, Ryan; Shumilov, Dmytro; Gryczynski, Zygmunt; Gryczynski, Ignacy.

In: Nanoscale, Vol. 5, No. 8, 21.04.2013, p. 3441-3446.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Polarization properties of fluorescent BSA protected Au25 nanoclusters

AU - Raut, Sangram Limbaji

AU - Chib, Rahul

AU - Rich, Ryan

AU - Shumilov, Dmytro

AU - Gryczynski, Zygmunt

AU - Gryczynski, Ignacy

PY - 2013/4/21

Y1 - 2013/4/21

N2 - BSA protected gold nanoclusters (Au25) are attracting a great deal of attention due to their unique spectroscopic properties and possible use in biophysical applications. Although there are reports on synthetic strategies, spectroscopy and applications, little is known about their polarization behavior. In this study, we synthesized the BSA protected Au25 nanoclusters and studied their steady state and time resolved fluorescence properties including polarization behavior in different solvents: glycerol, propylene glycol and water. We demonstrated that the nanocluster absorption spectrum can be separated from the extinction spectrum by subtraction of Rayleigh scattering. The nanocluster absorption spectrum is well approximated by three Gaussian components. By a comparison of the emissions from BSA Au 25 clusters and rhodamine B in water, we estimated the quantum yield of nanoclusters to be higher than 0.06. The fluorescence lifetime of BSA Au 25 clusters is long and heterogeneous with an average value of 1.84 μs. In glycerol at -20°C the anisotropy is high, reaching a value of 0.35. However, the excitation anisotropy strongly depends on the excitation wavelengths indicating a significant overlap of the different transition moments. The anisotropy decay in water reveals a correlation time below 0.2 μs. In propylene glycol the measured correlation time is longer and the initial anisotropy depends on the excitation wavelength. BSA Au25 clusters, due to long lifetime and high polarization, can potentially be used in studying large macromolecules such as protein complexes with large molecular weight.

AB - BSA protected gold nanoclusters (Au25) are attracting a great deal of attention due to their unique spectroscopic properties and possible use in biophysical applications. Although there are reports on synthetic strategies, spectroscopy and applications, little is known about their polarization behavior. In this study, we synthesized the BSA protected Au25 nanoclusters and studied their steady state and time resolved fluorescence properties including polarization behavior in different solvents: glycerol, propylene glycol and water. We demonstrated that the nanocluster absorption spectrum can be separated from the extinction spectrum by subtraction of Rayleigh scattering. The nanocluster absorption spectrum is well approximated by three Gaussian components. By a comparison of the emissions from BSA Au 25 clusters and rhodamine B in water, we estimated the quantum yield of nanoclusters to be higher than 0.06. The fluorescence lifetime of BSA Au 25 clusters is long and heterogeneous with an average value of 1.84 μs. In glycerol at -20°C the anisotropy is high, reaching a value of 0.35. However, the excitation anisotropy strongly depends on the excitation wavelengths indicating a significant overlap of the different transition moments. The anisotropy decay in water reveals a correlation time below 0.2 μs. In propylene glycol the measured correlation time is longer and the initial anisotropy depends on the excitation wavelength. BSA Au25 clusters, due to long lifetime and high polarization, can potentially be used in studying large macromolecules such as protein complexes with large molecular weight.

UR - http://www.scopus.com/inward/record.url?scp=84880902598&partnerID=8YFLogxK

U2 - 10.1039/c3nr34152f

DO - 10.1039/c3nr34152f

M3 - Article

C2 - 23474596

AN - SCOPUS:84880902598

VL - 5

SP - 3441

EP - 3446

JO - Nanoscale

JF - Nanoscale

SN - 2040-3364

IS - 8

ER -