Optical, Fluorescence Lifetime, Sensing and DNA Binding Studies of a Laser Dye

Abstract

Herein, the effects of media on the fluorescence characteristics (mainly quantum yield, lifetime and radiationless deactivation rate of the excited singlet state) of phenylene-1,4-ethylene-bis-(2-quinoxaline) laser dye, BQxVB have been reported. Also, the sensitivity of the dye to the proton has been tested by studying the effect of changing the acidic properties of the medium. As with polarity, the acidity of solution provokes spectral changes. As the acidity of the medium increases (using H2SO4 solutions), the pale yellow color of BQxVB changes to orange then violet and eventually to deep blue in concentrated acid solutions. The effect of metallic and bimetallic nanoparticles on the spectral behavior of BQxVB dye has been investigated. Additionally, the binding of the dye by β-cyclodextrin was investigated. The capped and binding of the dye with CT-DNA were visualized based on the spectral studies. Finally, a molecular docking analysis was carried out on five chosen proteins, which are largely responsible for the formation of CT-DNA, 4ASD-transferase, 3UW9 protein binding, 3DDC–hydrolase/apoptosis, 3L8-transferase/CT-DNA, and 4ICH-transcription. Based on the results, it has been clearly shown that BQxVB shows better docking with the 4ASD-transferase protein than the other selected proteins, with an estimated binding Gibbs energy of − 50.45 kJ·mol−1, a total intermolecular energy of − 55.09 kJ·mol−1, an inhibition constant of 1.48 nmol·dm−3, and a binding efficiency of 80%.