Fig. 1: Schematic illustration of halo-fluorescein generation singlet oxygen (1O2) in extremely acidic condition.
From: Halo-fluorescein for photodynamic bacteria inactivation in extremely acidic conditions
a Survival pH of most microorganisms and aciduric bacteria. In extremely acidic media (pH < 4.0), phage, antibiotics, and normal photosensitizers will lose their antibacterial activity; and b halogenated fluorescein exists in open form under extremely acidic condition, which can generate singlet oxygen upon photo irradiation for bacteria inactivation.
