Shape and Size\nDependent Antimicrobial and Anti-biofilm\nProperties of Functionalized MoS<sub>2</sub>

Bacterial\nresistance, accelerated by the misuse of antibiotics,\nremains a critical concern for public health, promoting an ongoing\nexploration for cost-effective and safe antibacterial agents. Recently,\nthere has been significant focus on various nanomaterials for the\ndevelopment of alternative antibiotics. Among these, molybdenum disulfide\n(MoS<sub>2</sub>) has gained attention due to its unique chemical,\nphysical, and electronic properties, as well as its semiconducting\nnature, biocompatibility, and colloidal stability, positioning it\nas a promising candidate for biomedical research. The impact of the\nshape and size of MoS<sub>2</sub> nanomaterials on the antibacterial\nactivity remains largely unexplored. In this study, we investigated\nthe effect of the shape and size of MoS<sub>2</sub> nanomaterials,\nsuch as quantum dots, nanoflowers, and nanosheets, on antimicrobial\nand anti-biofilm activity. As we had established earlier, functionalization\nwith positively charged thiol ligands can enhance colloidal stability,\nbiocompatibility, and antibacterial efficacy; we functionalized all\ntargeted nanomaterials. Our results revealed that functionalized MoS<sub>2</sub> quantum dots (F-MQDs) exhibited superior activity compared\nto functionalized MoS<sub>2</sub> nanoflowers (F-MNFs) and functionalized\nMoS<sub>2</sub> nanosheets (F-MNSs) against <i>Staphylococcus\naureus</i> (SA), both drug-resistant (methicillin) and nonresistant\nstrains. We observed very low minimum inhibitory concentration (MIC,\n30 ng/mL) for F-MQDs. The observed trend in antibacterial efficacy\nwas as follows: F-MQDs > F-MNFs ≥ F-MNSs. We explored the\nrelevant\nmechanism related to the antibacterial activity where the balance\nbetween membrane depolarization and internalization plays the determining\nrole. Furthermore, F-MQDs show enhanced anti-biofilm activity compared\nto F-MNFs and F-MNSs against mature MRSA biofilms. Due to the superior\nantibacterial and anti-biofilm activity of F-MQDs, we extended their\napplication to wound healing. This study will help us to develop other\nappropriate surface modified nanomaterials for antibacterial and anti-biofilm\nactivity for further applications such as antibacterial coatings,\nwater disinfection, and wound healing.