Fig. 1. Fluorescent spectra of HBT (10 μM) in the THF/H₂O mixture at different water fractions, λ_ex = 335 nm, λ_em = 470 nm. Inset: images of HBT (10 μM) under UV illumination at 365 nm in THF solution, THF/H₂O mixture (1 : 9, v/v) and power from left to right.