Eur. Phys. J. D (2014) 68: 308
https://doi.org/10.1140/epjd/e2014-50257-5

Regular Article

Spectral investigations on the influence of silver nanoparticles on the fluorescence quenching of 1,4-dimethoxy-2,3-dibromomethylanthracene-9,10-dione

¹ Department of Physics, Mother Teresa Women’s University, 624101 Kodaikanal, Tamil Nadu, India
² Laboratoire de Pharmaco-Chimie Radicalaire, Faculté de Pharmacie, Aix-Marseille University, CNRS,  
³ Institut de Chimie Radicalaire ICR, UMR 7273, 27 Boulevard Jean Moulin, 13385 Marseille Cedex 05, France

^a e-mail: ums10@yahoo.com

Received: 30 March 2014
Received in final form: 29 July 2014
Published online: 21 October 2014

Abstract

Silver nanoparticles (Ag NPs) of different sizes from 9 to 17 nm were synthesized by Creighton method and characterized using UV-vis spectroscopy and high resolution transmission electron microscopy (HRTEM). Fluorescence quenching of 1,4-dimethoxy-2,3-dibromomethylanthracene-9,10-dione (DMDBMAD) in methanol has been studied by fluorescence spectroscopy combined with UV-vis absorption spectroscopic techniques. It has been observed that the fluorescence intensity of DMDBMAD decrease with increase in the size of the Ag NPs. The quenching rate constant and association constant were determined using Stern-Volmer and Benesi-Hildebrand plots. The Stern-Volmer plot suggested that the quenching of DMDBMAD fluorescence by silver NPs was a dynamic process. The obtained value of the association constant infers that there is an association between DMDBMAD and the Ag NPs. Using Förster resonance energy transfer (FRET) theory, the distance between the donor (DMDBMAD) to acceptor (Ag NPs) and the critical energy transfer distance were obtained. Long range dipole-dipole interaction between the excited donor and ground state acceptor molecules is the dominant mechanism responsible for the energy transfer.