Biogenic synthesis and antimicrobial potency of iron oxide (Fe3O4) nanoparticles using algae harvested from the Mediterranean Sea, Egypt

Abstract

Green biosynthesis of nanoparticles gives a good alternate to chemical synthesis process. Two samples of iron oxide nanoparticles (Fe3O4-NPs) have been synthesized using brown (Colpomenia sinuosa) and red (Pterocladia capillacea) seaweed aqueous extracts, separately for reducing ferric chloride. The synthesized nanoparticles were characterized using the standard methods. The FT-IR results demonstrated that the tested extracts contained different biocompounds, which were responsible for synthesizing and capping of Fe3O4-NPs. The UV–Visible spectra of each obtained nanosample gave two absorption peaks at 402 and 415 nm signifying that Fe3O4 nanoparticles are formed. The SEM images of the two Fe3O4-NPs samples synthesized by C. sinuosa and P. capillacea aqueous extracts revealed their size as 11.24–33.71 nm and 16.85–22.47 nm, respectively. It was also found that Fe3O4-NPs was present in the nanospheres shape. Furthermore, the EDX spectra affirmed the existence of Fe3O4 nanoparticles in the two biosynthesized nanosamples. The synthesized Fe3O4-NPs exhibited wide spectrum of antibacterial potency against the growth of −ve (8.37 ± 6.62 mm) and +ve (5.75 ± 2.25 mm) Gram bacteria. Moreover, Fe3O4-NPs of C. sinuosa exhibited an excellent antifungal potency against Aspergillus flavus (9 mm) and Fusarium oxysporum (6 mm) compared with Fe3O4-NPs of P. capillacea (7 & 5 mm) and both negative and positive controls. Keywords: Antibacterial activity, Antifungal potency, Colpomenia sinuosa, Green synthesis, Pterocladia capillacea