Biological synthesis of gold and silver nanoparticles using leaf extracts of Crassocephalum rubens and their comparative in vitro antioxidant activities

Abstract

The use of plant and plant products in the synthesis of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) is made possible because of the natural inherent phytochemicals responsible for the reduction of respective metallic salts to nanoparticle forms, and ensuring therapeutic applicability. In this study, synthesis of AgNPs and AuNPs was performed using two different aqueous extraction methods for Crassocephalum rubens: maceration using laboratory method of extraction (cold aqueous extract of Crassocephalum rubens (AECR)), and decoction using traditional healer's method of extraction (hot aqueous crude extract of Crassocephalum rubens (CECR)). The synthesized nanoparticles were characterized using various methods, and in vitro antioxidant potential were thereafter investigated. The characterization results indicated the formation of mostly sphericalshaped AgNPs and AuNPs with surface plasmon resonance (SPR) band of 470 nm and 540 nm, respectively. The nanoparticles possess high antioxidant potentials but AECR synthesized AuNPs exhibited the least phytochemical contents and antioxidant potential when compared to other nanoparticles. It can therefore be concluded that extraction method and nanoparticle type are important factors that could influence the antioxidant properties of the nanoparticles. Further studies using these nanoparticles as anticancer or anti-inflammatory agent in both in vitro and in vivo are underway.

Facile synthesis of Au/ZnO/Ag nanoparticles using Glechoma hederacea L. extract, and their activity against leukemia

“…Such a clear change of color confirms the reduction of metals to the nano form. Similar changes have been observed by Thiruchelvi et al [ 26 ] and Adewale et al [ 27 ]. These authors [ 27 ] synthesized AgNPs and AuNPs.…”

“…Similar changes have been observed by Thiruchelvi et al [ 26 ] and Adewale et al [ 27 ]. These authors [ 27 ] synthesized AgNPs and AuNPs. According to the researchers colour changes suggest reduction and the synthesis of the nanoparticles, which are related to the surface plasmon resonance (SPR) band.…”

Nanotechnology-Based Delivery Systems for Antimicrobial Peptides

“…The plant-mediated synthesis is economical and make use of readily available and renewable plant materials such leaves, stems, roots, etc. Moreover, synthesis occurs in just one step, since the phytochemicals are able to act as reducing, capping, and stabilizing agents [110][111][112]. Previous studies have confirmed the safety of the biogenic method for MNP synthesis with effective antimicrobial activities against MDR bacteria [112,113].…”

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“…Likewise, Aftab et al (2021;2022); Aftab et al (2020) have reported that Cu-doped NiO thin films convey incredibly good anti-fungal as well as anti-bacterial characteristics. Furthermore, there are numerous other reports present in the literature in which other metals nanoparticles and their oxides have been used as antimicrobial agents (Aljabali et al, 2018;Roy et al, 2019;Adewale et al, 2020;Chand et al, 2020;Pachaiappan et al, 2021).…”