Distribution of SBPNS and LBPNS in cells. (a) TEM images of SBPNS-BSA-FITC and LBPNS-BSA-FITC in organelles such as Lysosome, Golgi apparatus, and Mitochondria. (b) Fluorescence confocal photographs of LBPNS-BSA-FITC in different organelles of A549 cells after 12 h of LBPNS-BSA-FITC exposure (green: LBPNS-BSA-FITC; blue: Nucleus; red: Endoplasmic Reticulum, Golgi apparatus, Mitochondrion, and Lysosome). (c) Fluorescence confocal photographs of SBPNS-BSA-FITC in different organelles of A549 cells after 12 h of SBPNS-BSA-FITC exposure (green: SBPNS-BSA-FITC; blue: Nucleus; red: Endoplasmic Reticulum, Golgi apparatus, Mitochondrion, and Lysosome). (d) Pearson’s co-localization coefficients of LBPNS-BSA-FITC or SBPNS-BSA-FITC with different organelles (n = 3). (e) LBPNS or SBPNS content in different organelles in BPNS-Au exposed cells (n = 3).