Extracellular Biosynthesis of Gold Nanoparticles by a Pathogen Fungus Fusarium oxysporum

Several different manufacturing techniques are in use, the most of the techniques are environmental unfriendly and expensive.Novel, rational, ecofriendly and simple biosynthetic method is developed for nanomaterials of different compositions.Gold nanoparticles have been extensively used in nanoelectronics, molecular electronics and also as a mediator in the construction of nanoscale electronics. Recently the utilization of biological systems such as some fungi has emerged as a novel method for the synthesis of gold nanoparticles.Fusarium oxysporum is an exciting biocatalyst for this purpose. Fusarium oxysporum, when challenged with aqueous solution of AuCl4–ions leads to their reduction and formation of gold nanoparticles. In a typical synthesis 20 g of Fusarium oxysporum, wet biomass was exposed to an aqueous solution of 1 mM chloroauric acid (HAuCl4) and the whole mixture was put into a shaker at 28 °C (200 rpm)for 48 h. After reduction of AuCl4–ions, nanoparticle solution was subjected to filtration, then the solid yield washed several times and heated at 150 °C overnight to remove water and fungal biomass