TF1 is designed to be a superior fluorophore alternative to EDANS. TF1 has (a). much stronger absorption; (b). much stronger fluorescence intensity; and (3). much less environment-sensitive fluorescence. Additionally their fluorescence is pH-independent from pH 3 to 11. These characteristics make this new dye family a superior alternative to EDANS. TF1-labeled peptides and nucleotides exhibit much stronger fluorescence and higher sensitivity than the ones labeled with EDANS. In pairing with our Tide Quencher™ 1 (TQ1), a variety of FRET peptides and nucleotides can be developed for detecting proteases and molecular beacons with enhanced sensitivity and stability.