ZnO nanomaterials with enhanced antimicrobial activity obtained by Eichhornia crassipes aqueous extract‐mediated synthesis

Abstract

BackgroundZinc oxide nanoparticles (ZnO NPs) were obtained through precipitation synthesis, using aqueous water hyacinth leaf extract (Eichhornia crassipes) under alkaline conditions. The effect of the extract on the physicochemical and antimicrobial properties of the ZnO was evaluated starting from concentrated extract (labeled as E100) and performing two dilutions of this concentrated extract at 50 and 25% in water (E50, and E25).ResultsThe FTIR spectra revealed, strong peaks around 3440 cm‐1, corresponding to vibrations from O‐H stretching and medium‐intense peaks at 1384, and 1327 cm‐1, assigned to C=C, ‐COOH, and C‐O‐C vibrations, which are related to the presence of the extract; a weak band at 884 cm‐1, and a broad band in the region below 600 cm‐1, indicate the presence of Zn‐O. The hydrodynamic size of the ZnOE100, ZnOE50, and ZnOE25 samples were 202, 244, and 313 nm, respectively. No significant variations on the Eg value were observed. FESEM images showed that the ZnO NPs have triangular‐like shapes, and agglomeration of the nanoparticles synthesized for the ZnOE25 sample. The Minimum Inhibitory Concentration (MIC) of the ZnO NPs showed no significant effects related to the concentration the plant extract used.Conclusionsvariations in particle size and zeta potential can be introduced in the ZnO varying the content of the extract, the presence of organic groups from the extract, along with positive zeta potential value, can promote the bactericide effect of ZnO nanomaterials prepared by bio‐assisted synthesis.This article is protected by copyright. All rights reserved.

Antifungal Activity of ZnO Nanoparticles Synthesized from Eichhornia crassipes Extract for Construction Applications

“…This is reflected in the presence of bands in the FTIR spectrum attributed to organic residues even after calcination, as demonstrated by Matinise et al [ 21 ] in the formation of ZnO with Moringa oleifera extract, where phytochemicals leave Zn 2+ metal ions chelated and stabilized during the calcination process. According to previous work [ 11 ], the aqueous extract of E. crassipes contains polyphenols and flavonoids, which are lightweight volatile compounds. Although the mechanism of extract-mediated synthesis has not been fully understood, it has been assumed that amine and carboxylic groups from the plant extract may adsorb onto the surface of the as-synthesized ZnO particles, as reported with the extract from Nigella sativa seeds [ 22 ].…”

“…Studies have demonstrated that extracts from this plant are effective in the synthesis of ZnO NPs using various precursors. For instance, using zinc nitrate with the extract of this plant not only improves the optical and morphological properties of the NPs [ 9 ] but also, when using zinc acetate, enhances their antimicrobial activity [ 10 , 11 ]. This study focuses on evaluating the antifungal properties of ZnO NPs assisted by E. crassipes extract, analyzing different concentrations of the extract and their impact on the physical and chemical properties of ZnO.…”