Synthesis of silver nanoparticles using the seaweed Codium capitatum P.C. Silva (Chlorophyceae)

The formation of silver nanoparticles by the reduction of aqueous silver metal ions during exposure to both fresh and dry seaweed extracts of Codium capitatum is reported. The silver nanoparticles obtained were characterized using UV-visible spectroscopy with characteristic absorption peaks at 422 and 425. nm. The color intensity at 422. nm increased for the duration of the incubation period. Using energy dispersive X-ray spectrometry (EDX) analysis, a distinct peak of silver was confirmed. Silver concentrations of 63.7% in the fresh and 56.0% in the dried seaweed were detected. The Fourier Transform Infrared (FTIR) spectra indicated the involvement of amine, peptide and sulfate groups in the C. capitatum extract for bioreduction and stabilization of AgNP. No synthetic reagents were used in this investigation, and thus it is an environmentally safe method with potential for biomedical and agriculture applications. © 2013 South African Association of Botanists.