Fig. 3. GNC antibacterial mechanism investigation. (A) Typical SEM images of MRSE after a 4 h treatment with PBS buffer (control), 2 μg mL⁻¹ Imp, 16 μg mL⁻¹ GNC, and a combination of Imp (2 μg mL⁻¹) and GNC (16 μg mL⁻¹). (B) Bright-field image (upper) and the corresponding NIR fluorescence image (lower) showing that the GNC + Imp treated MRSE bacteria were extensively aggregated. (C) TEM images of the PBS buffer- (control group, upper) and 16 μg mL⁻¹ GNC + 2 μg mL⁻¹ Imp-treated MRSE (lower).