From waste to value through sustainable synthesis of zinc oxide and nickel oxide Nanoparticles using Selenicereus undatus Peel extract: Anticancer activity against pancreatic Cancer cell line (PANC-1)

Cancer is the second leading cause of death globally, representing a significant public health challenge. The adverse effects of chemotherapy further complicate treatment. Nanoparticles have emerged as a promising solution, offering the potential to address these challenges through innovative approaches. This study explores the anticancer properties of zinc oxide (ZnO) and nickel oxide (NiO) nanoparticles, synthesized using Selenicereus undatus peel extract, an agricultural by-product. Using the Debye-Scherrer formula, the average crystallite size of the ZnO and NiO nanoparticles were calculated as 13 and 50 nm, also revealing hexagonal wurtzite and cubic phase structure via powder X-ray diffraction pattern (XRD). The fingerprint region (400–700 cm −1 ) in the Fourier-transform infrared (FTIR) spectra confirms the presence of symmetric stretching vibrations between metal‑oxygen bond. The Scanning Electron Microscope (SEM) revealed the combination of nano-flake and spherical morphologies, and Selected Area Electron Diffraction (SAED) pattern further supporting the XRD data. The optical bandgap for ZnO and NiO nanoparticles were calculated as 2.77 eV and 5.0 eV, using Tauc plot. Biological activity was assessed through antimicrobial testing against Staphylococcus aureus , Escherichia coli , and Propionibacterium acnes at various concentration, with gentamicin as the positive control. ZnO nanoparticles demonstrated superior antioxidant activity, with IC₅₀ value of 69.22 μg/mL, compared to NiO. Additionally, the anticancer efficacy of both nanoparticles was evaluated against pancreatic cancer cells (PANC-1). These findings suggest that biosynthesized ZnO and NiO nanoparticles may act as a potential material in pharmaceuticals. • Zinc oxide and nickel oxide nanoparticles are prepared from peel waste by environmental green method. • ZnO nanoparticles demonstrated superior antioxidant activity, with IC₅₀ value of 69.22 μg/mL than NiO nanoparticles. • Both nanoparticles perform well as anticancer agent against PANC-1 cell line.