Fig. 5. Time course of the signaling of PBT by F⁻ [PBT is 10 μM], [F⁻ is 20 μM], in a mixture of THF and Tris buffer solution (pH 8.0), (1 : 9, v/v). λ_ex = 335 nm, λ_em = 470 nm. Inset: the response curve of fluorescence intensity of PBT with F⁻ depending on the various time.