Eco-friendly Synthesis of Zinc Oxide Nanoparticles by Marine Sponge, Spongia officinalis : Antimicrobial and Insecticidal Activities Against the Mosquito Vectors, Culex pipiens and Anopheles pharoensis

Green synthesis of zinc oxide nanoparticles (ZnO-NPs) using the marine sponge, Spongia officinalis extract, and assessment of their antimicrobial and potential insecticidal activities were achieved in this study. Characterization of ZnO-NPs was done using UV–visible spectroscopy with surface plasmon resonance (SPR) peaked at wavelength 290 nm. Transmission electron microscopy (TEM) with spherical crystalline particle ranged from 3.22 to 11.5 nm. Fourier transform infrared (FTIR) spectral analysis showed the presence of different chemical function groups such as polysaccharides, hydrocarbons, phenols, amines, amides, and carboxylates that may help in reduction of zinc acetate and form ZnO-NPs. X-ray diffraction (XRD) indicated that ZnO-NPs were nanocrystalline. Additionally, dynamic light scattering (DLS) recorded 9 mV with negative polarity and conductivity of 274 µS/cm. Based on obtained results, Spongia officinalis ZnO-NPs ( So -ZnO-NPs) exhibited antibacterial and antifungal activities. Tested So -ZnO-NPs severely induced larvicidal activity for tested mosquitoes with LC 50 and LC 90 of 31.823 and 80.09 ppm for Culex pipiens and 12.634 and 66.118 ppm for Anopheles pharoensis , respectively. Fecundity was significantly reduced to 50% at 80 ppm for C. pipiens and 83% at 40 ppm for An. pharoensis . Adult (male and female) longevity was significantly shortened with almost all applied concentrations. Adult mortality increased significantly in relation to applied concentrations to reach about 96.67% at 60 ppm of So -ZnO-NPs in C. pipiens and 100% at 50 ppm in An. pharoensis . Overall, this study highlights the possibility of using S. officinalis –mediated ZnO-NPs for mosquito control and drug development.