Microwave-assisted rapid synthesis of silver nanoparticles using fucoidan: Characterization with assessment of biocompatibility and antimicrobial activity

Abstract

Silver nanoparticles (AgNPs) have gained attention due to their exceptional physicochemical properties and biological activities, owing to which they are extensively used in biomedical field. We synthesized AgNPs by rapid microwave-assisted method using fucoidan as a reducing agent. The synthesized fucoidan-AgNPs (F-AgNPs) were characterized for the structural and functional properties. The bactericidal effect and mode of action of F-AgNPs on the pathogenic bacteria and biofilm formation were investigated along with the cytotoxicity studies. The UV-Visible spectra of the F-AgNPs showed the surface resonance peak at 419 nm. The nanoparticles were spherical in shape with particle size of 59.5 ± 1.46 nm and polydispersity index (PDI) of 0.3 ± 0.01. Capping of fucoidan on AgNPs was confirmed by FTIR with characteristic peaks of sulfate group. Silver content of F-AgNPs was 87% with 13% contribution from the fucoidan moieties. The F-AgNPs showed antimicrobial activity against common pathogenic bacteria and was able to inhibit biofilm formation in Pseudomonas aeruginosa at 20 μg/mL concentration. The oxidative stress and intracellular protein leakage were observed due to the F-AgNP interaction with the cell bringing about bactericidal effect. The results highlight the synthesis and bioactivity of AgNPs doped with organic moieties for applications as antimicrobials.

Keywords: Green synthesis; Metal nanoparticles; Oxidative stress; P. aeruginosa biofilm inhibition.