Sargassum natans I Algae: An Alternative for a Greener Approach for the Synthesis of ZnO Nanostructures with Biological and Environmental Applications

Abstract

In this work, the influence of the Sargassum natans I alga extract on the morphological characteristics of synthesized ZnO nanostructures, with potential biological and environmental applications, was evaluated. For this purpose, different ZnO geometries were synthesized by the co-precipitation method, using Sargassum natans I alga extract as stabilizing agent. Four extract volumes (5, 10, 20, and 50 mL) were evaluated to obtain the different nanostructures. Moreover, a sample by chemical synthesis, without the addition of extract, was prepared. The characterization of the ZnO samples was carried out by UV-Vis spectroscopy, FT-IR spectroscopy, X-ray diffraction, and scanning electron microscopy. The results showed that the Sargassum alga extract has a fundamental role in the stabilization process of the ZnO nanoparticles. In addition, it was shown that the increase in the Sargassum alga extract leads to preferential growth and arrangement, obtaining well-defined shaped particles. ZnO nanostructures demonstrated significant anti-inflammatory response by the in vitro egg albumin protein denaturation for biological purposes. Additionally, quantitative antibacterial analysis (AA) showed that the ZnO nanostructures synthesized with 10 and 20 mL of extract demonstrated high AA against Gram (+) S. aureus and moderate AA behavior against Gram (-) P. aeruginosa, depending on the ZnO arrangement induced by the Sargassum natans I alga extract and the nanoparticles’ concentration (ca. 3200 µg/mL). Additionally, ZnO samples were evaluated as photocatalytic materials through the degradation of organic dyes. Complete degradation of both methyl violet and malachite green were achieved using the ZnO sample synthesized with 50 mL of extract. In all cases, the well-defined morphology of ZnO induced by the Sargassum natans I alga extract played a key role in the combined biological/environmental performance.

On the Performance of Sargassum derived Calcium Alginate Ion Exchange Resins for Pb2+ Adsorption: Batch and Packed Bed Applications

“…Sodium alginate was extracted from S. natans as previously reported by us (Mohammed et al 2018a, Mohammed et al 2020a. Briefly, S. natans was continuously washed to remove debris, salt and sand.…”

“…Within the past 12 years, the Caribbean and Latin America has seen massive onslaughts of Sargassum natans (brown seaweed) onto its shores, negatively impacting marine ecosystems resulting in a decrease in economic activities (Milledge &Harvey 2016). However, this waste seaweed has been shown to be an effective supply chain for sodium alginate production (Mohammed et al 2018b, Mohammed et al 2020a and as such, offers a plethora of uses (López-Miranda et al 2023, Mohammed et al 2023a, Mohammed et al 2023b, Mohammed et al 2019. However, in comparison to alginates produced from commercial seaweed sources such as Laminaria, Sargassum -derived alginate is of a low yield and quality in terms of purity (Mohammed et al 2020a) and as such is better suited for use in remediation of heavy metals as opposed to food and pharmaceutical value chains.…”