Singlet oxygen generation via two-photon excited FRET.
A new approach to two-photon excited photodynamic therapy has been developed. A dendritic array of eight donor chromophores capable of two-photon absorption (TPA) was covalently attached to a central porphyrin acceptor. Steady-state fluorescence measurements demonstrated that the donor chromophores transfer excited-state energy to the porphyrin with 97% efficiency. Two-photon excitation of the donor chromophores at 780 nm resulted in a dramatic increase in porphyrin fluorescence relative to a porphyrin model compound. Enhanced singlet oxygen luminescence was observed from oxygen-saturated solutions of the target compound under two-photon excitation conditions.
Dichtel
William R
WR
Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
Serin
Jason M
JM
Edder
Carine
C
Fréchet
Jean M J
JM
Matuszewski
Michael
M
Tan
Loon-Seng
LS
Ohulchanskyy
Tymish Y
TY
Prasad
Paras N
PN