Synthesis of Silver Nanoparticles Using Biopolymers for Cultivation of Chlorella vulgaris Protein Biomass

Abstract

Modern nanotechnology requires the development of an environmentally friendly, effective and affordable synthesis of silver nanoparticles used in medical, agricultural, and biotechnological areas. Natural compounds, including biopolymers, are promising resources for achieving this goal. This study involves the development of a method for synthesizing silver nanoparticles using chitosan, sodium carboxymethylcellulose, and sodium alginate as reducing agents and stabilizers. Reduction of silver ions by these biopolymers when heated to 55-65°C led to the formation of silver nanoparticles with sizes of 5 - 30 nm (silver nanoparticles chitosan), 2-11 nm (silver nanoparticles sodium alginate), 6-24 nm (sodium carboxymethylcellulose) for 30 minutes. The UV-visible spectrophotometer showed characteristic absorption peaks for silver nanoparticles chitosan (AgNPs Chs) at a wavelength of 464 nm and for silver nanoparticles sodium alginate (AgNPs SA) AgNPs sodium carboxymethylcellulose (Na-CMC) at a wavelength of 410 nm. The obtained infrared spectroscopy (IR) demonstrate a shift in the characteristic absorption band of biopolymer functional groups and their involvement in AgNPs synthesis. As a result of the 3D LS study, the charges of AgNPs coated with biopolymers were determined. The positive and negative charges of the AgNPs surface arise due to the presence of polycationic and polyanionic polymer coatings and interfere with the aggregation of nanoparticles. The performed method for obtaining silver nanoparticles is safe for cultivating protein biomass of the microalgae Chlorella vulgaris.