Green Synthesis of Silver‐Zinc Oxide Nanocomposites Using Spirulina platensis Biomass: Characterization and Biomedical Evaluation

Authors:
Publisher website
Google Scholar
Abstract
In this study, an aqueous extract of Spirulina platensis was utilized as a reducing and stabilizing agent for the green synthesis of silver‐zinc oxide nanocomposites (Ag‐ZnO). The S. platensis extract was optimized at a concentration of 0.5%, stored at 4°C and centrifuged at 6000 rpm for 5 min. Ultraviolet–visible spectroscopy of the extract showed a broad absorbance band in the 330‐ to 380‐nm region and a shoulder in the 520‐ to 620‐nm range, corresponding to bioactive metabolites. The formation of silver‐zinc oxide nanocomposites was confirmed by characteristic absorbance in the 300‐ to 400‐nm region under optimized conditions. Particle size analysis using a Zetasizer revealed an average particle size of approximately 204 nm with a polydispersity index of 0.28. Functional groups, crystallinity, and surface morphology were characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, and scanning electron microscopy. Due to increasing concerns over antibiotic resistance, the antibacterial potential of the synthesized nanocomposites was evaluated by the disk diffusion method showing a maximum zone of inhibition of 35 ± 0.4 nm against Pseudomonas aeruginosa at 13 μg/mL. The Ag‐ZnO nanocomposites exhibited a notable antioxidant activity, indicating a concentration‐dependent DPPH radical scavenging activity with a maximum inhibition of 67.3% at 517 nm, compared to 60.12 for ascorbic acid. Furthermore, cytotoxic evaluation against the BT‐549 breast cancer cell line revealed a half‐maximal inhibitory concentration (IC 50 ) of 6.401 μg/mL. These findings indicate that S. platensis –mediated silver‐zinc oxide nanocomposites exhibit promising biological activity.
Funding Information
  • Princess Nourah Bint Abdulrahman University (PNURSP2026R890)

This publication has 26 references indexed in Scilit: