Biosynthesis of gold nanoparticles utilizing marine sponge Acanthella elongata (Dendy, 1905)

The growing trend of exploring bacteria, fungi, actinomycetes and plant materials for the biosynthesis of nanoparticles is considered as eco friendly and a green technological approach. In this backdrop the present study reports the synthesis of gold (Au) nanoparticles from gold precursor using the extract derived from the marine sponge, Acanthella elongata (Dendy, 1905) belonging to the primitive phylum Porifera. Water-soluble organics present in the marine sponge extract were mainly responsible for the reduction of gold ions to nano-sized Au particles. The sponge extract added to 10-3 M HAuCl4 aqueous solution at 45°C changed to pinkish ruby red color solution and confirm the bioreduction within 4 h with continuous stirring. UV-visible spectrum of the aqueous medium containing gold nanoparticles showed a peak around 526 nm. High-resolution transmission electron micrographs (HR-TEM) confirmed the monodispersed and spherical shaped with the size ranges from 7 to 20 nm, however a maximum number of particles were in 15 nm diameter. Through Fourier transform infrared spectroscopy (FT-IR) analysis, the reducing agent in the marine sponge extract was identified which is attributed for the biosynthesis of gold colloids. The XRD analysis respects the Bragg's law and confirmed the crystalline nature of the gold nanoparticles.