Fig. 4: In vitro evaluation of antibacterial activity against planktonic bacteria.

Plate colony patterns (a) and quantitative analysis (b) comparing the anti-MRSA efficacy of the tetrazine-enhanced MOF Zn-TDP with other conventional photosensitive MOFs (25 µg/mL) (n = 3 independent biological replicates, data are presented as mean ± SD). Colony-forming unit (CFU) counts and antibacterial rates of MRSA (25 µg/mL, light exposure 15 min for Zn-TDP and A@Zn-TDP, 250 µg/mL, light exposure 30 min for Ni-TDP and A@Ni-TDP) (c), E. coli (50 µg/mL, light exposure 15 min for Zn-TDP and A@Zn-TDP, 200 µg/mL, light exposure 30 min for Ni-TDP and A@Ni-TDP) (e), and S. aureus (25 µg/mL, light exposure 15 min for Zn-TDP and A@Zn-TDP, 200 µg/mL, light exposure 30 min for Ni-TDP and A@Ni-TDP) (g) under different treatment conditions, with corresponding quantitative results shown in (d), (f), and (h), respectively (n = 3 independent biological replicates, data are presented as mean ± SD). (The colors of each group in (d), (f) and (h) correspond to the colors labeled above them.) i SYTO-9/PI bacterial live (green fluorescence)/dead (red fluorescence) staining images of MRSA, E. coli and S. aureus after different treatments, scale bars = 200 μm. j SEM images illustrating the changes on the morphology of bacteria, scale bar = 1 μm, (false color applied). Images from three independent biological replicates were acquired, and a representative example is shown in (i) and (j). Control denotes the group received an equal volume of physiological saline followed by either dark or light exposure, whereas Control+D indicates administration of an equal volume of physiological saline followed by dark exposure. D for darkness, L for light. Statistical significance was determined by one-way ANOVA followed by Tukey’s post hoc test for multiple comparisons (b, d, f, and h). Source data are provided as a Source Data file.