Zinc oxide quantum dots (ZnO QDs) are well known antimicrobial agents against both gram-positive and gram-negative bacterial species, and some fungal species [1-3], and this study demonstrates the ability of ZnO QDs to generate reactive oxygen species (ROS) under ambient and UV-A irradiation, where they are shown to significantly inhibit the growth of shiga-like toxin producing E. coli, C. auris and MRSA, as well as reducing the time in microbial inactivation. Scanning electron micrographs show microbial cells underwent various structural cell defects such as cracks and fissures, with intracellular contents leaching out of dead cells. Moreover, AFM-IR was used to shed light on ROS-mediated toxicity to the cell membrane of gram-negative bacteria, E. coli, when light irradiation was applied to generate the photocatalytic activity of ZnO QDs. Principal Component Analysis (PCA) revealed UV-activated ZnO QDs significantly altered three functional groups attributed to the protein, polysaccharides and lipid structures of the cell membrane, with Amide I group demonstrating the strongest changes and is a common target of ROS damage, as they are found on the outermost groups of phospholipids structure of the membrane [4]. The following study demonstrates the applicability and effectiveness of UV-irradiated QDs to elicit faster killing of drug-resistant microbes.