Fig. 1.

The comparison of solubility of HPQ, HTPQ, HYPQ, AMC (a water-soluble fluorochrome), and DCM-NH₂ (a liposoluble fluorochrome). The absorbance spectra of HPQ, HTPQ, and HYPQ (10 μM) in PBS containing 1% DMSO and 10% glycerol (A) and in dichloromethane (B). The black and red lines indicate the absorbance spectra intensity of these compounds before and after filtration. (C) Diffusion experiments of DCM-NH₂, HYPQ, and AMC were performed at the interface between water and dichloromethane (amphiphilic environment). (D) Agarose gels containing HYPQ and AMC were immersed in PBS (pH = 7.4), and then real-time images were obtained every 10 min for a total of 30 min. HYPQ showed good antidiffusion ability, while AMC diffused rapidly within 30 min. All the fluorescent photos were conducted under UV lamp excitation at 365 nm.