Laser-induced hole filling by energy transfer between chromophores bound to DNA

We have studied the laser-induced hole filling of primary holes of the bodipy derivatives covalently linked to DNA by excitation of the intercalated molecules of acridine orange. We found that the Förster energy transfer from donor to acceptor increases hole filling. An induced broad hole in the spectra of the acceptor indicates energy transfer from the excited donor to various sites of electronic transitions of the acceptors. In addition, the decrease of the antiholes of the acceptor suggests that the excited state two-level systems play an important role for the antihole reversion. It is most likely that after energy transfer to the excited state of the acceptor, the mechanism of hole filling is antihole reversion to its original configuration. Furthermore, our preliminary results showed that energy transfer-induced hole filling from the intercalated donor to two individual acceptors at each end of DNA is independent of the presence of other acceptors.