Spectroscopic investigation of water-soluble alloyed QDs with bovine serum albumin.
We present here a systematic investigation on the interaction between a water-soluble alloyed semiconductor quantum dot and bovine serum albumin using various spectroscopic techniques i.e. fluorescence quenching, resonance light scattering and synchronous fluorescence spectroscopy. The analysis of fluorescence spectrum and fluorescence intensity indicates that the intrinsic fluorescence of bovine serum albumin (BSA) gets quenched by both static and dynamic quenching mechanism. The Stern-Volmer quenching constants, energy transfer efficiency parameters, binding parameters and corresponding thermodynamic parameters (ΔH0, ΔS0and ΔG0) have been evaluated by using van 't Hoff equation at different temperatures. A positive entropy change with a positive enthalpy change was observed suggesting that the binding process was an entropy-driven, endothermic process associated with the hydrophobic effect. The intermolecular distance (r) between donor (BSA) and acceptor (CdSeS/ZnS quantum dots) was estimated according to Förster's theory of non-radiative energy transfer. The synchronous fluorescence spectra revealed a blue shift in the emission maxima of tryptophan which is indicative of increasing hydrophobicity. Negative ΔG0values implied that the binding process was spontaneous. It was found that hydrophobic forces played a role in the quenching process. Copyright © 2016 John Wiley & Sons, Ltd.
Laser Spectroscopy Programme & UGC-Centre with Potential for Excellence, Department of Physics, Karnatak University, Dharwad, 580003, India.
K S
KS
Adarsh
Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai, 400 085, India.
M K
MK
Singh
Laser Spectroscopy Programme & UGC-Centre with Potential for Excellence, Department of Physics, Karnatak University, Dharwad, 580003, India.
M G
MG
Kotresh
Molecular Endocrinology and Development Laboratory, Department of Zoology, Karnatak University, Dharwad, 580003, India.
Laxmi S
LS
Inamdar
Laser Spectroscopy Programme & UGC-Centre with Potential for Excellence, Department of Physics, Karnatak University, Dharwad, 580003, India.
M A
MA
Shivkumar
Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai, 400 085, India.
B N
BN
Jagatap
BLDE University, Bijapur, India.
B G
BG
Mulimani
Laser Spectroscopy Programme & UGC-Centre with Potential for Excellence, Department of Physics, Karnatak University, Dharwad, 580003, India.
S R
SR
Inamdar
D000818:Animals; D019187:Cadmium Compounds / Q000737:chemistry*; D002417:Cattle; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D012995:Solubility; D013050:Spectrometry, Fluorescence; D013440:Sulfides / Q000737:chemistry*; D013816:Thermodynamics; D014867:Water / Q000737:chemistry; D017967:Zinc Compounds / Q000737:chemistry*
D019187:Cadmium Compounds; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; D014867:Water; D012710:Serum Albumin, Bovine; C058667:cadmium selenide; C031238:zinc sulfide
FRET; QDs; bovine serum albumin; fluorescence quenching; resonance light scattering; synchronous fluorescence scan