Photoabsorption and Resonance Energy Transfer Phenomenon in CdTe�Protein Bioconjugates: An Insight into QD�Biomolecular Interactions

Aaydha, C. Vinayaka and Thakur, M. S. (2011) Photoabsorption and Resonance Energy Transfer Phenomenon in CdTe�Protein Bioconjugates: An Insight into QD�Biomolecular Interactions. Bioconjugate Chemistry, 22. pp. 968-975.

PDF Bioconjugate_Chem.,_2011,_22_(5),_pp_968–975.pdf Restricted to Registered users only Download (5MB)

Citations: 6 in Google Scholar

Abstract

Luminescent quantum dots (QDs) possess unique photophysical properties, which are advantageous in the development of new generation robust fluorescent probes based on Forster resonance energy transfer (FRET) phenomena. Bioconjugation of these QDs with biomolecules create hybrid materials having unique photophysical properties along with biological activity. The present study is aimed at characterizing QD bioconjugates in terms of optical behavior. Colloidal CdTe QDs capped with 3-mercaptopropionic acid (MPA) were conjugated to different proteins by the carbodiimide protocol using N-(3-dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride (EDC) and a coupling reagent like N-hydroxysuccinimide (NHS). The photoabsorption of these QD�protein bioconjugates demonstrated an effective coupling of electronic orbitals of constituents. A linear variation in absorbance of bioconjugates at 330 nm proportionate to conjugation suggests a covalent attachment as confirmed by gel electrophoresis. A red shift in the fluorescence of bovine serum albumin (BSA) due to conjugation inferred a decrease in Stokes shift and solvent polarization effects on protein. A proportionate quenching in BSA fluorescence followed by an enhancement of QD fluorescence point toward nonradiative dipolar interactions. Further, reduction in photobleaching of BSA suggests QD�biomolecular interactions. Bioconjugation has significantly influenced the photoabsorption spectrum of QD bioconjugates suggesting the formation of a possible protein shell on the surface of QD. The experimental result suggests that these bioconjugates can be considered nanoparticle (NP) superstructures for the development of a new generation of robust nanoprobes.

Item Type:	Article
Uncontrolled Keywords:	QD bioconjugate
Subjects:	600 Technology > 05 Chemical engineering > 01 Biotechnology and Bioengineering
Divisions:	Fermentation Technology and Bioengineering
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	26 Sep 2010 10:12
Last Modified:	30 May 2012 11:52
URI:	http://ir.cftri.res.in/id/eprint/9708

Actions (login required)

View Item