Relative biofilm formation and bacterial viability of P. aeruginosa PAO1 in the presence of different concentrations of bPEI-capped AgNCs (A) and AgNPs (B). Fluorescence microscopy images of P. aeruginosa AH298-GFP incubated with 1 μM of AgNPs (C) and AgNCs (D) and untreated control that formed biofilms (E). A fluorescent strain of P. aeruginosa was used for fluorescence microscopy and ThT dye was used to stain the biofilms. Panels F, G and H represent the hyperspectral images (HSI) along with the SPR spectra of AgNPs, P. aeruginosa incubated with 1 μM AgNPs and P. aeruginosa control, respectively. Helium ion microscopy (HIM) and TEM micrographs of P. aeruginosa incubated with AgNPs (HIM: panel I, TEM: panel J), P. aeruginosa incubated with AgNCs (HIM: panel K, TEM: panel L) and P. aeruginosa control (HIM: panel M, TEM: panel N). ROS generation by P. aeruginosa, relative to positive control (H2O2), upon incubation with AgNPs and AgNCs (panel O).