Fig. 3

a Relative TPA spectra of the material. TPE as a function of the wavelength (720–820 nm) at 98.56 nJ pixel⁻¹ that was used to monitor the signals. Delivered dose, 3 μg mL⁻¹ water-soluble C₆₀(OH)₄₆ or C₆₀(OH)₂₁ fullerenol. The number of surviving b material-treated bacteria was determined by CFU counting assay and is expressed as the percentage (%) for c bacteria that corresponds to the unit of CFU mL⁻¹. Delivered dose, OD600 ~ 0.05 of E. coli and 0–9 μg mL⁻¹ water-soluble fullerenol. d Measurement of phosphorescence spectra at 1270 nm for material. Delivered dose, 3 μg mL⁻¹ water-soluble fullerenol. Data are means ± SD (n = 6)