Fig. 3From: A Review on Enhancing the Antibacterial Activity of ZnO: Mechanisms and Microscopic InvestigationTwo-photon fluorescence microscopy and bright-field images of AZn2-labeled (a–j) S. aureus and (k–f) K. pneumoniae. Both species were treated with ZnO NPs (NA, NP, and CN) and ZnCl2 of 0.35 mM. Two-photon images were collected at 500–620 nm upon 780 nm excitation with femtosecond pulses. Reproduced from ref. [16] with permission from ElsevierBack to article page