A Potential Carcinogenic Pyrene Derivative under Förster Resonance Energy Transfer to Various Energy Acceptors in Nanoscopic Environments

Abstract

Picosecond-resolved Förster resonance energy transfer (FRET) from various vibronic bands in benzo[a]pyrene (BP) shows a strong dependency on the spectral overlap of an energy acceptor in a confined environment. Our study on the dipolar interactions between BP and different acceptors, including ethidium (Et), acridine orange (AO), and crystal violet (CV), at the surface of a model anionic micelle revealed that the Förster distance (R0) and the rate of energy transfer is dependent on the individual spectral overlap of the vibronic bands of BP with the absorption spectra of the different energy acceptors. The differential behavior of the vibronic bands is compared with that of different dyes [quantum dots (QDs)] in a "dye-blend" (mixture) under FRET to an energy acceptor. Comparison of the FRET of the QDs with that of BP confirmed the independent nature of the dipolar interaction of the vibronic bands with other organic molecules, and the use of deconvolution techniques in the interpretation of the donor-acceptor (D-A) distance was also justified. We also showed that the consideration of differential FRET from the vibronic bands of BP and from the QDs in the dye-blend is equally acceptable in theoretical frameworks including the Infelta-Tachiya model and D-A distribution analysis in nanoenvironments.

Molecular co-localization of multiple drugs in a nanoscopic delivery vehicle for potential synergistic remediation of multi-drug resistant bacteria

“…al. has further studied acceptor association induced quenching of donor transients in nanoscopic micellar surface by a potential carcinogen benzo[a]pyrene (BP) as donor in presence of various acceptors 61 which shows the available number of acceptor molecule in micellar surface to quench donor fluorescence is ~ 1 for a FRET efficiency of ~ 86%.

Figure 5 Time-resolved fluorescence transients of BT in CTAB in absence and in presence of two different concentration of RF.

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Role of caffeine in DNA recognition of a potential food‐carcinogen benzo[a]pyrene and UVA induced DNA damage

“…As BP and Et have comparable spectral overlaps of their absorption coefficients with the transilluminator emission at 312 nm, both the dyes have similar absorption of photons from the said source. On the other hand, the fluorescence quantum yield of BP is around unity (Banerjee et al , ), while that of DNA bound Et (Le Pecq, ) is ~0.15, which is the reason behind the extensive fluorescence of BP under the transilluminator. However, BP undergoes through nonradiative ET pathway upon associating with DNA.…”

Host‐Assisted Delivery of a Model Drug to Genomic DNA: Key Information from Ultrafast Spectroscopy and in silico Study

“…where k 2 is a factor describing the relative orientation in space of the transition dipoles of the donor and acceptor and is calculated according to the equation given elsewhere [20] …”

“…where k 2 is a factor describing the relative orientation in space of the transition dipoles of the donor and acceptor and is calculated according to the equation given elsewhere. [20] The refractive index (n) of the medium is assumed to be 1.5. Q D , the quantum yield of the donor in the absence of acceptor is measured to be 0.54 and 0.53 in SDS micelles and genomic DNA respectively.…”