Fluorescence spectra of ss DNA and ds DNA containing 6-MI are shown based on their quantum yields measured relative to 6-MI monomer (black) using an excitation wavelength of 340 nm. The Φrel of 6-MI in ssDNA (teal, pink, brown, dark green) is highly quenched (Φrel < 0.2). The dsDNA molecules containing either the AFTAA or the AAFTA sequences exhibit significantly higher quantum yields (Φrel ≥ 0.7) (blue, magenta, green). While formation of the AFT07 duplex has only a slight effect on the quantum yield.