Fig. 3.

In vitro imaging of Gram-negative and Gram-positive bacteria. a Confocal fluorescence images of four different kinds of bacteria (EC, SA, ML, and PA) after incubation with GP-Ce6-SiNPs. Scale bar: 10 μm. b Intensity profiles of ROI across the line shown in ML in panel (a) with confocal microscope. c Confocal fluorescence images of EC and SA treated with NaN₃ and then incubated with GP-Ce6-SiNPs for 2 h. Scale bar: 10 μm. d Confocal fluorescence images of EC and SA incubated with GP with different concentrations (0, 2, 20 mg mL⁻¹) for 5 min and then incubated with GP-Ce6-SiNPs for 2 h. Scale bar: 25 μm. e TEM (scale bar: 1 μm) and zoom-in TEM (scale bar: 30 nm) images of intact EC and cell membrane of EC treated with GP-Ce6-SiNPs. f TEM (scale bar: 20 nm) and zoom-in TEM (scale bar: 5 nm) images of GP-Ce6-SiNPs nanoparticles in cell lysate of EC. g Confocal fluorescence images of the mixture of ARPE cells and EC, pure ARPE cells, the mixture of human blood and EC, pure human blood after incubation with GP-Ce6-SiNPs. Scale bar: 25 μm. h Histogram quantifying the level of GP-Ce6-SiNPs transport. Statistical analysis was performed using a one-way ANOVA analysis. Error bars represent the standard deviation obtained from three independent measurements (***p < 0.001, n = 3). In the above experiments, the final concentration of GP-Ce6-SiNPs is 10 mg mL⁻¹ (3.6 mg mL⁻¹ of GP and 100 μg mL⁻¹ of Ce6). Source data are provided as a Source Data file