Synthesis and Structural Characterization of SiO₂ Nanoparticles Using Extract of Gracilaria Crassa Via Green Chemistry Approach

Biologically synthesized nanoparticles via biological entities are produced with less negative impact on the environment and without expensive chemicals, which have biocompatibility and are eco-friendly. Gracilaria crassa is a well-known marine red alga that is edible and unique and is the commercial source of agar and agarose production. In this work, Gracilaria crassa-mediated SiO₂ NPs were synthesized by the green synthesis method. In order to characterize the physicochemical properties of the synthesized SiO₂ NPs, a variety of microscopic and spectroscopic approaches were used, including imaging with Field emission scanning electron microscopy, Energy-dispersive X-ray analysis, UV spectrophotometry, X-ray diffraction analysis, Fourier-transform infrared spectroscopy, Zeta potential, and Thermo gravimetric analysis. These results shown that Gracilaria crassa-mediated SiO₂ NPs were amorphous nature, negatively charged -15.5 mV and spherical shape in size of 20-50 nm. The antioxidant capacity of synthesised SiO₂ NPs was examined by 2,2-Diphenyl-1-picrylhydrazyl assay and it observed as IC₅₀ value of 49.4 μg/mL denotes that could counteract the production of free radicals and oxidative stress. The characteristics of the synthesized Gracilara crassa-mediated SiO₂ NPs suggest their application as potential antioxidant agents.