Eco-friendly synthesis of star-shaped Zn nanoparticles using Beta vulgaris peel extract and evaluation of their antibacterial, photocatalytic, and cytotoxic activities

In this study, for the first time, Zn nanoparticles were created using the root peel of Beta vulgaris by a green method. Synthesized Zn nanoparticles have been characterized via UV–Vis spectroscopy, Zeta potential analysis, XRD, FTIR, TEM, and FESEM-EDX techniques. The synthesis of zinc-based nanoparticles was confirmed by spectroscopic techniques. UV-Vis analysis presented a broad absorption peak in the UV region, centered around 300 nm. Furthermore, a zeta potential of − 21.6 mV characterized the particles’ negative surface charge and suggested moderate colloidal stability. The XRD pattern of Zn nanoparticles revealed crystalline structures, and FESEM and TEM images of Zn nanoparticles displayed a star-shaped morphology. The photocatalytic activity of NPs for the color degradation of Rhodamine B (RhB) and Methylene Blue (MB) dyes has been investigated under UV light, and the results show 97% and 98% degradation, respectively. The antibacterial activity of the Zn nanoparticles was evaluated at a concentration of 1 mg/mL against the gram-positive bacterium Staphylococcus aureus (ATCC 1112 and clinical isolates), Enterococcus faecalis (ATCC and clinical isolates), and gram-negative bacterium Escherichia coli (ATCC and clinical isolates) and Pseudomonas aeruginosa (PAO1 and S7). The cytotoxic effects of Zn nanoparticles were assessed over a concentration range of 7 to 500 µg/mL on both normal L929 fibroblast cells and MCF-7 breast cancer cells. After 24 h of incubation, the IC₅₀ value for the MCF-7 cell line was determined to be 284 µg/mL, while no significant cytotoxicity was observed on L929 cells. To our understanding, this is the initial report synthesizing star-shaped Zn nanoparticles utilizing B. vulgaris root peel as an eco-friendly reducing and stabilizing agent, highlighting their potential for environmental and biomedical applications.