Fig. 5: Evaluation of the photodynamic bacteria inactivation performance of TIF (light source: 520 nm green LED, 35 mW/cm2) with L. plantarum as a model bacteria in extremely acidic conditions.
From: Halo-fluorescein for photodynamic bacteria inactivation in extremely acidic conditions
a Survival rates of L. plantarum after treated with 0.5 μM photosensitizers and irradiated for 10 min (pH = 2.5, coating plate method, Supplementary Fig. 46; for Zn-tpp and PC, 620 nm red LED was used; *P < 0.05, **P < 0.01, ***P < 0.001). Error bars represent standard deviation, n = 3 independent replicates; b pictures of the bacterial cultures under different conditions (bacteria were first treated and then plated on solid media for colony quantification); c dark toxicity evaluation of TIF. Error bars represent standard deviation, n = 3 independent replicates; d Zeta potentials of L. plantarum, L. plantarum + TIF, and TIF in different media (inset: the pictures of L. plantarum + TIF at different pH, washed twice to remove unabsorbed TIF). Error bars represent standard deviation, n = 3 independent replicates; e live/dead bacteria staining of TIF-treated L. plantarum (scale bar: 20 μm; pH 2.5; concentration of TIF: 10 μM; irradiation time: 1 h); f SEM images of L. plantarum with or without TIF under light irradiation (scale bar: 1 μm; the same condition as e); and g TEM images of L. plantarum with or without TIF under light irradiation (scale bar: 0.5 μm and 200 nm; the same condition as e).
