Influence of silver nanoparticles on absorption and fluorescence properties of laser dyes

Abstract

The interaction of silver nanoparticles with four laser dyes, namely, LD-425, LD-489, LD-473, and LD-423, dispersed in methanol has been studied at room temperature by absorption and fluorescence spectroscopy. The silver nanoparticles were synthesized by chemical reduction and estimated size is 11 nm according to Mie theory. The changes in absorption spectrum of these dyes with the addition of silver nanoparticles suggest possible interaction with the silver nanoparticles. The magnitudes of the association constants are estimated using the Benesi–Hildebrand model. Fluorescence quenching has been observed for all the dyes with the addition of silver nanoparticles of different concentrations. The Stern–Volmer plots of fluorescence quenching in the case of LD-425 and LD-489 are found to be linear, suggesting the fluorescence quenching is because of the dynamic quenching process. But in the case of LD-473 and LD-423, the Stern–Volmer plots are nonlinear showing positive deviation and the fluorescence quenching in these dyes is because of static quenching processes. Also, it is found that the fluorescence quenching is not solely due to diffusion.

Effect of solvents, solvent mixture and silver nanoparticles on photophysical properties of a ketocyanine dye

“…. From the slope and intercept of this plot, k a is found to be 3.52 × 10 3 M –1 , and is within the range of those previously reported for other dyes . This indicates a strong association between the silver nanoparticles and the investigated dye.…”

“…Silver nanoparticles were synthesized by a chemical reduction method that involved the reduction of silver nitrate solution by sodium borohydride solution. Details of synthesis were reported in our previous article . In this method, sodium borohydride and silver nitrate were used in a 6 : 1 ratio for better stability of the silver nanoparticles, as suggested by Solomon .…”

Investigation of role of silver nanoparticles on spectroscopic properties of biologically active coumarin dyes 4PTMBC and 1IPMBC

“…From the slopes and intercepts of these plots, k a values were calculated for both the dyes and are given in Table 1. These values of k a are within the range of those previously reported for other dyes [6,7,9,18]. This indicates the strong association between silver nanoparticles and the dyes investigated.…”

“…The details of synthesis were reported in our previous paper [9]. In this method, sodium borohydride and silver nitrate were used in 6:1 ratio as suggested by Solomon [14].…”

“…The study of interaction of metal nanoparticles with biologically active fluorescent organic molecules has received much attention in recent years [6][7][8][9][10]. Such studies would open up new ideas in the development of diagnostic techniques, sensors and targeted drug delivery systems.…”