Avaliação dos potenciais antioxidante, catalítico e ecotóxico de nanopartículas de prata estabilizadas com emprego de Polissacarídeos extraídos de macroalgas marinhas

Abstract

In the present work, the antioxidant, catalytic and ecotoxic potentials of silver nanoparticles synthesized using sodium borohydride as a reducing agent in the presence of fractions rich in polysaccharides extracted from seaweed belonging to the genera Gracilaria sp., Padina sp. and Ulva sp. Marine algae were subjected to aqueous extraction of biomolecules and isolation of polysaccharides. In sequence, the aqueous extracts and isolated polysaccharides were subjected to yield analysis and physico-chemical characterization by UV-Vis, CLAE, GPC spectroscopy techniques, elemental analysis, infrared spectroscopy and analysis of phytochemical composition to assess the degree of purity of the isolated polymers. The silver nanoparticles supported in a polymeric matrix based on the isolated polysaccharides, were characterized by UV-Vis absorption spectroscopy, Dynamic Light Scattering (DLS), zeta potential (Pz) and Atomic force microscopy (MFA). The estimated average diameters of the AgNPs showed sizes in the range of 70 to 140 nm with PdI between 0.188 to 1,000 and surface load between -18.7 to - 79.6 mV. At laboratory temperature, the antioxidant and catalytic performance of AgNPs was investigated against the methods of DPPH and chemical reduction of Bromocresol Green (BG) and Methylene Blue (MB) dyes. It was found that AgNPs have good antioxidant potential, promoting an efficient catalytic effect by the process of chemical reduction of dyes with a low degree of toxicity compared to the in vivo model in Artemia salina with a 100% survival rate in all tested concentrations