Abstract
The bioactivity of semiconductor nanocomplexes has been poorly studied in the field of pesticide science. In this research, the synthesis of zinc nanoparticles was accomplished through new effortless green chemistry process, using the Ulva lactuca seaweed extract as a reducing and capping agent. The production of U. lactuca-fabricated ZnO nanoparticles (Ul-ZnO Nps) was characterized by powder X-ray diffraction (XRD), UV–visible, Fourier transform infrared (FTIR) spectroscopy, selected area electron diffraction (SAED) analysis and transmission electron microscopy (TEM). The U. lactuca-fabricated ZnO NPs were tested for their photodegradative action against organic dyes, as well as for antibiofilm and larvicidal activities. The UV visible absorbance spectrum of Ul-ZnO NPs exhibited the absorbance band at 325nm and TEM highlighted average crystallite sizes of nanoparticles of 10–50nm. Methylene blue (MB) dye was efficiently corrupted under sunlight in presence of Ul-ZnO NPs. Excellent bactericidal activity was shown by the Ul-ZnO Nps on Gram positive (Bacillus licheniformis and Bacillus pumilis) and Gram negative (Escherichia coliand Proteus vulgaris) bacteria. High antibiofilm potential was noted under both dark and sunlight conditions. The impact of a single treatment with Ul-ZnO NPs on biofilm architecture was also analyzed by confocal laser scanning microscopy (CLSM) on both Gram positive and Gram negative bacteria. Moreover, Ul-ZnO NPs led to 100% mortality of Aedes aegypti fourth instar larvae at the concentration of 50μg/ml within 24h. The effects of ZnO nanoparticle-based treatment on mosquito larval morphology and histology were monitored. Overall, based on our results, we believe that the synthesis of multifunctional Ul-ZnO Nps using widely available seaweed products can be promoted as a potential eco-friendly option to chemical methods currently used for nanosynthesis of antimicrobials and insecticides.
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•Eco-friendly green synthesis of ZnO nanoparticles was done using the Ulva lactuca extract (Ul).•The Ul-ZnO nanoparticles showed efficient photocatalytic activity on methylene blue.•Ul-ZnO nanoparticles showed high antibiofilm activity on 4 species of Gram positive and negative bacteria.•High toxicity of ZnO nanoparticles was observed against Aedes agypti larvae.•Histopathological effects caused by ZnO nanoparticles penetration in the insect's body were studied.