Near-IR emissive chlorin-bacteriochlorin energy-transfer dyads with a common donor and acceptors with tunable emission wavelength.
Design, synthesis, and optical properties of a series of novel chlorin-bacteriochlorin energy transfer dyads are described. Each dyad is composed of a common red-absorbing (645-646 nm) chlorin, as an energy donor, and a different near-IR emitting bacteriochlorin, as an energy acceptor. Each bacteriochlorin acceptor is equipped with a different set of auxochromes, so that each of them emits at a different wavelength. Dyads exhibit an efficient energy transfer (≥0.77) even for chlorin-bacteriochlorin pairs with large (up to 122 nm) separation between donor emission and acceptor absorption. Excitation of the chlorin donor results in relatively strong emission of the bacteriochlorin acceptor, with a quantum yield Φf range of 0.155-0.23 in toluene and 0.12-0.185 in DMF. The narrow, tunable emission band of bacteriochlorins enables the selection of a series of three dyads with well-resolved emissions at 732, 760, and 788 nm, and common excitation at 645 nm. Selected dyads have been also converted into bioconjugatable N-succinamide ester derivatives. The optical properties of the described dyads make them promising candidates for development of a family of near-IR fluorophores for simultaneous imaging of multiple targets, where the whole set of fluorophores can be excited with the common wavelength, and fluorescence from each can be independently detected.
Department of Chemistry and Biochemistry, University of Maryland, Baltimore County , 1000 Hilltop Circle, Baltimore, Maryland 21250, United States.
Zhanqian
Z
Yu
Marcin
M
Ptaszek
D004735:Energy Transfer; D005456:Fluorescent Dyes / Q000737:chemistry*; D015394:Molecular Structure; D010777:Photochemistry; D011166:Porphyrins / Q000737:chemistry*; D019265:Spectroscopy, Near-Infrared
D005456:Fluorescent Dyes; D011166:Porphyrins; C452433:bacteriochlorin; C006969:chlorin