Exploring the Multifunctionality of Cu/Mn‐Doped <scp>ZnS</scp> Nanosheets: A Promising Material for Cancer Therapy and Advanced Antimicrobial Applications

This study investigates the structural, morphological, hydrodynamic, colloidal stability, anticancer, antibacterial, antioxidant, and hemolytic properties of Cu and Mn doped ZnS nanosheets (NSs). XRD examination indicated that the produced NSs exhibit high purity with a cubic structure. The average crystallite size was determined to be 1.66 nm for ZCMn1, 1.60 nm for ZCMn2, 1.26 nm for ZCMn3, and 1.39 nm for ZCMn4 NSs (ZnS = ZCMn1; Zn_0.98Cu_0.02S = ZCMn2; Zn_0.97Mn_0.01Cu_0.02S = ZCMn3; Zn_0.96Mn_0.02Cu_0.02S = ZCMn4). TEM analysis showed that the synthesized NSs exhibit a crumpled nanosheet morphology with agglomerated particles. The ZCMn4 NSs displayed the smallest hydrodynamic size and the best colloidal stability. The ZCMn4 NSs also demonstrated superior antibacterial efficacy, with zones of inhibition (ZOI) measuring 14mm, 14 mm, 17 mm, 16 mm, and 13 mm for S. aureus, E. faecalis, P. aeruginosa, E. coli, and C. albicans, respectively. Antioxidant and hemolytic activities were also evaluated, further highlighting the multifunctionality of the synthesized nanomaterials. Notably, the ZCMn4 NSs exhibited minimal hemolytic activity, with a lysis rate of only 0.33% at a dosage of 500 μg/mL. The doped and dual-doped ZnS NSs exhibited strong and selective cytotoxic effects against melanoma cells while sparing normal melanocytes. Furthermore, a TUNEL assay was performed to confirm that the reduction in cell viability resulted from apoptotic cell death. These findings underscore the potential of Mn and Cu-doped ZnS nanosheets as promising therapeutic nanomaterials for cancer treatment, drug delivery, MRI, and other biological applications.