Impact of Solvents, Magnesium Oxide and Aluminium Oxide Nanoparticles on the Photophysical Properties of Acridine Orange Dye

Abstract

Absorption and fluorescence spectroscopy techniques were applied to investigate the photophysical characteristics of acridine orange (AO) dye in solvents that included distilled water, dimethyl sulfoxide (DMSO), acetone and ethanol in various concentrations (1×10-4–1×10-6) M. All of the samples were served at room temperature. The relationships between various parameters describing the strength of optical transitions in atoms and molecules were reviewed. This study expresses various viewpoints by describing how concentration and solvent affect the dye's absorption and fluorescence spectra. The absorption spectra of AO exhibit a band at (490 nm), except for DMSO, which shifts more towards red by 5 nm. The fluorescence spectra show a blue shift in AO aqueous solution around 6 nm until (0.5×10-4) M, followed by a red shift at around 7 nm at (1×10-6) M. There is a blue shift in (1×10-5) M for DMSO at around 4 nm, then a 10 nm red shift in higher concentrations as well as a 9 nm red shift in acetone and 6 nm in ethanol. Adding magnesium oxide nanoparticles (MgO NPs) quenched AO in both absorption and fluorescence spectra, whereas maximum fluorescence and intensity increased when aluminium oxide nanoparticles (Al2O3 NPs) were added to the solution. KEYWORDS Laser dye, absorption spectrum, fluorescence spectrum, MgO NPs, Al2O3 NPs