Dependence of fluorescence intensity of IAs (0.5 μM) on gradual addition of TA[Q], showing a 1:1 binding by the curve fitting (solid line). Inset: Photographs of the solutions under UV illumination (from left to right: EPI, BER, COP, PAL, WOR, JAT, SAN, CHE, NIT) with TA[Q] at 0.2 μM.