Utilization of Marine Algae Biomass for Eco-Friendly Obtaining of Gold Nanoparticles

In this study, three types of algae biomass (Ulva lactuca, Cladophora vagabunda and Callithamnion corymbosum) were used as reducing agents to obtain gold nanoparticles, without the addition of supplementary chemical reagents. Experiments were carried out as a function of the initial pH (1.0–6.0), the amount of biomass (2.0–20.0 g/L) and the initial concentration of Au(III) ions (4.0–120 mg/L), to establish the optimal conditions for obtaining gold nanoparticles. The highest efficiency of obtaining gold nanoparticles was reached at pH = 2.0, 4.0 g/L algae biomass and high Au(III) ions concentrations (120 mg/L), in the case of Cladophora vagabunda (20.14 mg/g), followed by Ulva lactuca (18.08 mg/g) and of Callithamnion corymbosum (15.98 mg/g). Encouraging experimental results highlight the possibility of using Cladophora vagabunda algae biomass to obtain gold nanoparticles in aqueous solution.