Fig. 1: Oxidase-like AgPd0.38 generates surface-bound ROS.
From: Surface-bound reactive oxygen species generating nanozymes for selective antibacterial action
a Transmission electron microscopy (TEM) images of AgPd nanocages with different Pd content. b Absorbance (λ = 266 nm) of ascorbic acid (AA) treated (for 3 h) with a nanocage (8 μg/mL in PBS) or PBS. c Absorbance (λ = 266 nm) of AA treated with AgPd0.38 (8 μg/mL) in the presence of O2, N2, or Ar. Controls are AA-treated similarly but with PBS. d Fluorescence intensity (λem = 433 nm) of ABDA treated with AgPd0.38 (64 μg/mL) or PBS. e Fluorescence intensity (λem = 433 nm) of ABDA treated with AgPd0.38 at different concentrations. f Schematic illustration on the preparation of Ce6/PLGA@lipid, which was done by coating a Chlorin e6 (Ce6)-preloaded PLGA (poly(lactic-co-glycolic acid)) nanoparticle (i.e., Ce6/PLGA) with a PEGylated lipid bilayer. g TEM images of Ce6/PLGA and Ce6/PLGA@lipid. Red arrow indicates the lipid bilayer coating. h Fluorescence emission spectra of SOSG treated with Ce6/PLGA@lipid or Ce6/PLGA (5 μg/mL in Ce6 dose) upon irradiation with a solar simulator (at 0.1 W/m2, 5 min). Control is SOSG-treated similarly but with PBS. i Schematic illustration on the inability of the lipid bilayer coating in Ce6/PLGA@lipid to affect the outward translocation of free ROS generated by PLGA-encapsulated Ce6 upon light irradiation, thereby leading to unaffected oxidation of ROS probes in the bulk solution compared to Ce6/PLGA. j Schematic illustration on the preparation of AgPd0.38@lipid, done by coating AgPd0.38 with a PEGylated lipid bilayer. k TEM images of AgPd0.38 and AgPd0.38@lipid. Red arrow indicates the lipid bilayer coating. l Fluorescence emission spectra of SOSG treated with AgPd0.38@lipid or AgPd0.38 (64 μg/mL, for 3 h), with that of SOSG-treated similarly but with PBS included as a control. m Schematic illustration on the strikingly suppressed oxidation of ROS probes in the bulk solution by AgPd0.38@lipid, as compared to that by AgPd0.38, indicative of effective separation of the ROS generated by AgPd0.38 from the ROS probes in the bulk solution due to the presence of the lipid bilayer coating, suggesting that the ROS on AgPd0.38 is surface-bound. Source data are provided in the Source Data file.
