Joshi , Prachi and Shewale , Vasundhara and Pandey , Ravindra and Shankar , Virendra and Hussain , Saber and Karna , Shashi P. (2011) Tryptophan-Gold Nanoparticle Interaction: A First-Principles Quantum Mechanical Study. Journal of Physical Chemistry C, 115 (46). pp. 22818-22826. ISSN 1932-7447

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Abstract

The nature of interaction between tryptophan (Trp) and gold (Au) nanoparticles is studied using first-principles density functional theory calculations and described in terms of equilibrium configurations, interaction energies, density of states, molecular orbitals, and charge density. The calculated results find the binding involving both carboxyl and indole functional groups with mixed salt–bridge and charge–solvation structure to be energetically preferred and is attributed to the stronger-than-expected π interactions facilitated by the indole group in Trp. In the Trp–Au conjugates, modification of the molecular orbitals associated with Trp occurs because states associated with Au and the hybrid orbitals have mixed metal–molecule character. We find that the nonradiative energy transfer from excited states of Trp to hybrid states of Trp–Au may reduce intrinsic fluorescence intensity of Trp in the conjugated system.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s ACS.
Uncontrolled Keywords:	Proteins; Fluorescence; Surface; Water; Size; Dft
Subjects:	Chemistry > Physical Chemistry Materials Science Nanoscience/ Nanotechnology
Divisions:	UNSPECIFIED
Depositing User:	Mr. Abhishek Yadav
Date Deposited:	05 Oct 2012 12:25
Last Modified:	05 Oct 2012 12:25
URI:	http://npl.csircentral.net/id/eprint/667

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