Resonance energy transfer and competing processes in donor–acceptor of sodium zinc (II)-2,9,16,23-phthalocyanine tetracarboxylate molecule

Abstract

An important issue that should be taken into consideration when applying the molecules in photodynamic therapy (PDT) of cancer is the occurrence of homo-resonance energy transfer process between them. We have determined the probability of energy transfer for sodium zinc (II)-2,9,16,23-phthalocyanine tetracarboxylate (ZnPc(COONa) 4 ) molecules in aqueous NaOH solution. The homo-quenching effect of the molecule was also measured by calculating the diffusion controlled bimolecular rate constant of k q = 6.5 × 10 9 M −1 s −1 , which did not show a significant competition with the rate constant of homo-resonance energy transfer process at the applied concentration of the molecules (6 μM). The Förster radius (R 0 ) for ZnPc(COONa) 4 molecules was calculated to be 42 Å. The availability of these calculations should facilitate the potential application of ZnPc(COONa) 4 molecule as an anticancer drug in PDT.

Highly efficient fluorescence resonance energy transfer in co-encapsulated BODIPY nanoparticles

“…These values are almost identical in THF and CH2Cl2 (Table 1). Substantial overlap of the emission spectrum of compound 2 with the absorption spectrum of compound 1 satisfies the spectral overlap requirement for FRET (Figure 3) [7][8][9][10]. According to Figure 3, there is a slight overlap of the normalized absorption spectra of compounds 1 and 2 which can cause simultaneous excitation of both chromophores.…”

“…FRET does not require a physical contact or interaction between the donor and the acceptor molecule. However, the rate of FRET depends on (i) the extent of overlap between the donor emission spectrum and the acceptor absorption spectrum, (ii) the relative orientation of the donor emission and the acceptor excitation dipoles, (iii) the separation between the donor and the acceptor (typically 10-100 Å), and (iv) the fluorescence quantum yield of the donor [7][8][9][10]. Extreme sensitivity of FRET to D−A separation distance allows utilization of FRET in monitoring a variety of biological processes that cause changes in molecular proximity.…”

Forster Resonance Energy Transfer in a Hybrid System of CdTe Quantum dots-RhB

“…Forster resonance energy transfer (FRET) is widely used for the detection of interactions between a directly excited emitter of fluorescence (donor) and a molecule of an energy acceptor [1][2][3][4][5][6][7][8]. The efficiency of FRET depends on several factors ：(i) distance between the donor and the acceptor, (ii) overlap degree of the donor emission and the acceptor absorption spectra and (iii) relative orientation of the donor emission and the acceptor absorption transition dipole moments.…”