Fig. 3

In vitro synergistic photothermal antibacterial activity of nanoparticles containing both RIF and ICG. a Colony photos of P. aeruginosa upon treatment with RIF (8 µg mL^− 1), NP-ICG (15 µg mL^− 1 of ICG), NP-ICG/RIF and NM-NP-ICG/RIF (containing RIF: 8 µg mL^− 1, ICG: 15 µg mL^− 1) under NIR laser irradiation (808 nm, 1.5 W cm^− 2) for 5 min or no NIR laser irradiation (initial bacterial loading: ~10⁸ CFU mL^− 1). b Photothermal heating curves of different samples incubated with P. aeruginosa under NIR laser irradiation (808 nm, 1.5 W cm^− 2) for different time periods (n = 3). c CLSM images of P. aeruginosa under the same treatment conditions as aforementioned in Fig. 3A, and followed by staining with LIVE/DEAD BacLight bacterial viability kit where green fluorescent dye stains all the bacterial cells and red PI dye stains bacterial cells with damaged membrane (Scale bar: 20 μm). d The counts of P. aeruginosa colonies under the same treatment conditions as aforementioned in Fig. 3a (n = 3)