Phyconanotechnology: synthesis of silver nanoparticles using brown marine algae Cystophora moniliformis and their characterisation

Biosynthesis of metallic nanoparticles is a relatively new developing area of nanotechnology which has economic and environmentally friendly advantages over conventional chemical and physical methods of synthesis. In this paper, we report for the first time, on the synthesis of silver nanoparticles (AgNPs) using the Australasian brown marine algae Cystophora moniliformis. An extract of this alga was used as a reducing and stabilising agent. Temperature-dependent variation of the size of the AgNPs was observed. Agglomeration of the nanoparticles was observed at high temperatures. The average size of the AgNPs formed at temperatures < 65A degrees C was 75 nm, whereas they were > 2 mu m at higher temperatures. The X-ray diffraction (XRD) pattern revealed face-centered cubic structure of the formed Ag nanoparticles.