Biosynthesized ZnO-NPs Using Sea Cucumber (Holothuria impatiens): Antimicrobial Potential, Insecticidal Activity and In Vivo Toxicity in Nile Tilapia Fish, Oreochromis niloticus

In this study, a sustainable and eco-friendly method was used to prepare zinc oxide nanoparticles (ZnO-NPs) using sea cucumber aqueous extract. Then, ZnO-NPs were characterized by instrumental analysis (UV-vis, HR-TEM, XRD, FT-IR, DLS) evaluated for their possible antibacterial, antifungal, insecticidal activities. Additionally, the toxicity of in vivo against Nile Tilapia (Oreochromis niloticus). The collected from Gulf Suez (Red Sea) at Al-Ain Al-Sokhna coast Egypt identified as Holothuria impatiens. prepared Hi-ZnO-NPs peaked 350 nm UV–Vis spectral analysis. They showed quasi-spherical shaped particles with sizes ranging 13 47 predominate size 26 indicated HR-TEM. XRD pattern revealed crystalline phase an average 17.2 calculated Debye–Scherrer equation. FTIR role H. impatiens biological molecules biosynthesis process ZnO-NPs. negative zeta potential −19.6 mV, demonstrating moderate stability. Biosynthesized broad antimicrobial activity Gram-positive bacteria (S. aureus ATCC 25923 E. feacalis), Gram-negative typhi, K. pneumonia coli), filamentous fungi (Aspergillus niger). demonstrated larvicidal mosquito, Culex pipiens (LC50 = 2.756 ppm LC90 9.294 ppm), adulticidal action housefly, Musca domestica (LD50 4.285 LD90 22.847 ppm). Interestingly, did not show mortality effects tilapia fish niloticus), highlighting safety highly exposed, non-target organisms. However, histopathological hematological investigations provided dose-dependent impacts tilapia. Overall, data provide approach synthesizing novel multiple biomedical properties potentially low fish.