Fluorescence Relaxation Dynamics of Acridine Orange in Nanosized Micellar Systems and DNA

Abstract

In this paper, we report a detailed study of the fluorescence relaxation dynamics of a well-known fluorescent DNA intercalator, acridine orange (AO), in reverse micelles (RM), micelles, and DNA using picosecond resolved fluorescence spectroscopy. Solvation studies of AO in AOT reverse micelles (RM) containing water indicate the locations of AO close to the interface and those in RM containing NaOH; there are two types of AO--one in the nonpolar oil phase and the other at the interface. The bound water at the reverse micellar interface is found to be much more rigid than that at the micellar interface of sodium dodecyl sulfate (SDS) micelles. Dynamic light scattering (DLS) studies allow for the determination of the hydrodynamic radius and the overall tumbling motion of the macromolecules. Wobbling-in-cone data analysis of the temporal fluorescence anisotropy decay allows for determination of restriction on the motion of fluorophores attached to the macromolecules. This model further applied to AO-intercalated genomic DNA and synthetic oligonucleotides within their structural integrity (as confirmed through circular dichroism (CD) studies) shows that AO experiences less restriction in genomic salmon sperm DNA compared with that in synthetic oligonucleotides, and among the oligonucleotides, the ones with AT base pairs are much more rigid. This study would invoke further research on the dynamical nature of AO in restricted environments.

Hydrogen Bonding Barrier‐Crossing Dynamics at Biomimicking Surfaces

“…Thus, it might be inferred that no significant change in probe location occurs upon increase in temperature, and it resides at the interface. The rotational relaxation times obtained in this study are much slower than those of rotational times reported in bulk water [155,156]. For all the studied temperatures, r(t) is characterized by a slow decay, with the presence of a considerable offset.…”

Binding of BOBO-3 Intercalative Dye to DNA Homo-Oligonucleotides with Different Base Compositions

“…One of the most extensive studies on the base content dependence of emission enhancements, quantum yields, and lifetimes for 10 monomeric and bichromophoric cyanine dyes was reported by Netzel et al 6 The differences in emission enhancement as a function of the base content for cyanine dyes complexed to dsDNA can be caused by different types of binding sites in deoxyadenosine-deoxythymidine (dAdT) and deoxyguanosine-deoxycytidine (dGdC) sequences and by different degrees of flexibility of the double helix. 17 Excited-state electron transfer (ET) quenching by nucleosides could also alter the emission enhancement. 18 ET between guanosine nucleosides is favored because this nucleoside is the easiest to oxidize.…”

Mixed anionic and zwitterionic surfactant based microemulsions as vehicles for solubilizing organodiselenides

“…Shaw and Pal [22] have reported the photophysics and molecular dynamics of DNA by employing Acridine Orange (AO) as a probe.…”

“…Since, it is insoluble in isooctane; it will probably be partitioned between anionic interface and water. The AO molecules in the reverse micellar media usually exhibits two peaks [22,23] (i) basic AO in the nonpolar isooctane phase ($375 nm) and (ii) protonated AO lying at the reverse micellar interface ($490 nm). The structures of AO in basic and protonated form are presented in Scheme 2.…”