Biosynthesis of Silver Nanoparticles by Using Invasive Caulerpa cylindracea Sonder

Abstract

Caulerpa cylindracea is an invasive seaweed in the Mediterranean Sea. In this study, we propose an alternative method to utilise the biomass of C. cylindracea to synthesize silver nanoparticles (AgNPs). UV-VIS spectroscopy, FT-IR and X-ray diffraction were used in characterization steps. The results show that optimum conditions such as time, initial concentration of AgNO3 and temperature were found to be 240 min, 0.1 M AgNO3 and 85˚C, respectively. The measured particle size of the synthesized AgNPs were 22 nm. Since AgNPs were encapped by the secondary metabolites of C. cylindracea, the synthesized AgNPs showed stable solubility in aqueous conditions. The experimental data related to synthesis of AgNPs were modelled by using artificial neural network (ANN). Agitation time and rate, temperature, pH, concentration of AgNO3 and extract were chosen as input and absorbance values were chosen as output. ANN modelling study exhibited that Bayesian regularization backpropagation, scaled conjugate gradient backpropagation and Levenberg-Marquardt backpropagation algorithms better modelled the experimental data compared to studied 11 backpropagation algorithms. In conclusion, biomass of invasive seaweeds can be used to synthesize AgNPs for commercial use and this will bring a new perspective to utilisation of the biomass of invasive seaweeds. A possible economical value may create a stress on the spread of these alien species in the Mediterranean Sea.