Characterization and investigation of biofabricated ZnO nanoparticles using Caulerpa sertularioides for antioxidant and antibacterial purposes

Nanoparticles synthesized from marine macroalgae have garnered significant attention in biomedical research due to their potential applications. In this study, zinc oxide nanoparticles (ZnO NPs) were synthesized using an extract from Caulerpa sertularioides (Cs) as a reducing agent. The synthesized C. sertularioides-mediated zinc oxide nanoparticles (Cs-ZnO NPs) were characterized by UV-visible spectroscopy, X-ray diffraction (XRD), Fouriertransform infrared spectroscopy (FT-IR), Field emission scanning electron microscopy (FE -SEM), Highresolution transmission electron microscopy (HR-TEM), and Dynamic light scattering (DLS) techniques. In the UV-visible spectroscopy analysis, the maximum absorption peak was observed at 364 nm. XRD analysis confirmed that the Cs-ZnO NPs had a crystalline structure. FE -SEM and HR-TEM demonstrated that the Cs-ZnO NPs were mostly spherical in shape and the size ranged between 20 and 87 nm. The zeta size and potential of CsZnO NPs at 97.89 nm and 14.1 mV were confirmed by DLS analysis. The antioxidant activities were tested by various in vitro assays, and the results demonstrated that Cs-ZnO NPs exhibit dose-dependent antioxidant activities. Further, Cs-ZnO NPs were highly effective against Vibrio harveyi both as an antibacterial and anti-biofilm agent. The toxicity assessment of Cs-ZnO NPs on Artemia nauplii indicated moderate toxicity. Overall, this study concludes that Cs-ZnO NPs have potential application in the aquaculture industry to prevent pathogenic illnesses and enhance disease resistance without causing adverse effects.