Picosecond study of the luminescence and transient absorption of methylene blue–polynucleotide complexes
Abstract
Transient absorption signals observed after picosecond laser excitation of Methylene Blue (MB+) bound to double-stranded polydeoxyguanylic-deoxycytidylic acid {poly[d(G–C)]·poly[d(G–C)]} are assigned to the dye's singlet excited state reacting with a lifetime of 4 ps to form the electron-transfer product (MB˙·G˙+˙) which itself decays with a lifetime of 130 ps.