Biosintesis dan karakterisasi nanopartikel silika (SiO2) dari sekam oleh Fusarium oxysporum

Abstract

Silica nanoparticles have many advantages such as large surface, heat resistance, mechanical strength, and inert. Therefore has been used as a precursor catalyst, an adsorben, and a composit filter. Biosynthesis is a method to find the nanoparticles through enzymatical mechanism from microbe. This research aims to produce the silica nanoparticles by F.oxysporum with a phase growth and an amount of rice husk as substrate optimization. F.oxysporum is grown in a media pH 4-6, incubation temperature 27ºC, and 200 rpm aeration system. The presence of extracellular enzymes F.oxysporum views based on their ability in reducing the silica which is contained in the rice husk. The number of optimum substrate is determined by the two treatments, 2.5 gram and 5 gram of rice husks. The F.oxysporum biomass has been harvested in 72th hour, when the cells entered the stationary phase based on the growth curve. SEM analysis results for both types of treatments shows the number of particles agregate each other and have undifferent particle size with variations in size between 200-1000 nm. The three highest peaks are found in the FTIR absorption spectrum which is located at peaks 3408.18 cm-1 for the group H2O, peaks 1639.04 cm-1 for the group CO32-, and peaks 1078.71 cm-1 for the group Si-O-Si. The husk with F.oxysporum treatment indicated to be changed from the structure basic forms (amorphous) to the crystalline silica nanoparticles (crystoballite) based on XRD analysis.