FRET lasers via DNA scaffolds
Yuze Sun, Siyka I. Shopova, Chung-Shieh Wu, Stephen Arnold, and Xudong
PNAS, 107, 16039-16042(2010).
Abstract: Optofluidic dye lasers hold great promise for adaptive photonic
devices, compact and wavelength-tunable light sources, and micro
total analysis systems. To date, however, nearly all those lasers are
directly excited by tuning the pump laser into the gain medium
absorption band. Here we demonstrate bioinspired optofluidic
dye lasers excited by FRET, in which the donor-acceptor distance,
ratio, and spatial configuration can be precisely controlled by DNA
scaffolds. The characteristics of the FRET lasers such as spectrum,
threshold, and energy conversion efficiency are reported. Through
DNA scaffolds, nearly 100% energy transfer can be maintained
regardless of the donor and acceptor concentration. As a result,
efficient FRET lasing is achieved at an unusually low acceptor
concentration of micromolar, over 1,000 times lower than that in
conventional optofluidic dye lasers. The lasing threshold is on the
order of μJ∕mm2. Various DNA scaffold FRET lasers are demonstrated
to illustrate vast possibilities in optofluidic laser designs.
Our work opens a door to many researches and applications such
as intracavity bio/chemical sensing, biocontrolled photonic devices, and biophysics.