5-fluorouracil-loaded Mn-doped ZnO nanocomposite: synthesis, characterization, and antibacterial activity

Antimicrobial resistance has intensified the search for alternative strategies to combat drug-resistant bacterial pathogens. Although 5-fluorouracil (5-FU) exhibits intrinsic antibacterial activity, its clinical antimicrobial application may be limited by dose-dependent toxicity. This study aimed to develop a 5-FU-loaded Mn-doped ZnO nanocomposite and evaluate its structural characteristics and antibacterial activity against the Gram-positive bacterium Staphylococcus aureus and the Gram-negative bacterium Escherichia coli . The nanocomposite was synthesized by co-precipitation and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), UV–visible spectroscopy, and Fourier-transform infrared (FTIR) spectroscopy. Complementary spectroscopic and structural analyses evaluated the optical band-gap characteristics and successful incorporation of Zn, Mn, and 5-FU. The 5-FU-loaded Mn-doped ZnO nanocomposite demonstrated notable antibacterial activity against both bacterial strains. At concentrations of 15 and 10 μL, the nanocomposite produced inhibition zones of 16.8 and 13.8 mm against S. aureus , respectively, and 14.8 and 12.5 mm against E. coli . The greater inhibition against S. aureus indicates comparatively higher susceptibility of the Gram-positive strain to the nanocomposite. Overall, the findings demonstrate that 5-FU-loaded Mn-doped ZnO nanocomposites exhibit promising broad-spectrum antibacterial activity and may offer a nanomaterial-based strategy to enhance the antimicrobial utility of 5-FU while potentially reducing the required drug dose.