Biosynthesis of Silver and Gold Nanoparticles Using Aqueous Extract of Codonopsis pilosula Roots for Antibacterial and Catalytic Applications

Abstract

In this study, biogenic silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized by a green approach using an aqueous extract from Codonopsis pilosula (CP) roots as a reducing and stabilizing agent. The formation of CP-AgNPs and CP-AuNPs was confirmed and optimized by UV-Vis spectroscopy. The CP-AgNPs and CP-AuNPs obtained under optimum conditions of metal ion concentration, reaction temperature, and reaction time were characterized by high-resolution transition electron microscopy (HR-TEM), selected area electron diffraction (SAED) analysis, field-emission scan electron microscopy (FE-SEM), powder X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) spectroscopy, dispersive X-ray spectroscopy (EDX), and dynamic light scattering (DLS) method. It has been found that the biosynthesized CP-AgNPs and CP-AuNPs were formed in spherical shape with an average size of 10±2.5 nm and 20±3.2 nm, respectively. The biosynthesized metallic nanoparticles exhibited selective bacterial activity against three bacterial strains including two Gram-positive bacteria of Bacillus subtilis and Staphylococcus aureus and one Gram-negative bacteria of Escherichia coli. Meanwhile, there was no antibacterial activity detected toward Gram-negative Salmonella enteritidis. CP-AgNPs and CP-AuNPs also manifested an excellent catalytic performance in the reduction of 1,4-dinitrobenzene, 2-nitrophenol, 3-nitrophenol, and 4-nitrophenol.

Reduction mechanisms of Ag(I) and Au(III) in the synthesis of silver and gold nanoparticles using leaf extract of Terminalia catappa

“…The strongest peak was observed at 2.2keV. The same peak for Au element was also confirmed by Doan et al [10]. Based on the elemental content, AuNP precipitate consists of Au (79.75%) and O (9.01%), and the remainings are Si, Na and Al (1.44-5.56%).…”

“…These absorption peaks were not observed in the spectrum of starting material solutions of AgNO 3 1mM and HAuCl 4 0.5mM, and leaf extract of Terminalia catappa as well. Furthermore, this can be a proof that reduction reactions of Au(III) → Au(0) and Ag(I) → Ag(0) have been occurred [10,25,26]. Nevertheless, the existence of elemental Au and Ag should be demonstrated by advanced spectroscopic techniques such as XPS (X-Ray Photoelectron Spectroscopy) or EDXS (Energy Dispersive X-Ray Spectrometry), as suggested by those authors [10,25,26].…”

“…The above synthetic protocol by plant extract or biomass exemplifies the promising application of the green synthesis of metal nanoparticles. Very recently, green metal nanoparticles have been synthesized using various natural products such as opuntia (Opuntia ficus-indica) [9], aqueous extract of Codonopsis pilosula roots [10], cinnamon (Cynnamon zeylanicum) bark extract and powder [11], leaf extract of Dalbergia sissoo [12]. Ketapang (Makassarese: talise) is found as a specific plant in South Sulawesi region and has been used for traditional medicine since the ancient time.…”

Silver and Gold Nanoparticles from Limnophila rugosa Leaves: Biosynthesis, Characterization, and Catalytic Activity in Reduction of Nitrophenols

“…The change in color of the solution caused by the surface plasmon resonance phenomenon (SPR) was recorded to monitor the formation of MNPs. The optimization process was performed to obtain the nanoparticles with the best size and morphology, as similarly described in our previous works [35,36]. Three main factors, including reaction time, metallic 2…”

Sono-Biosynthesis and Characterization of AuNPs from Danube Delta Nymphaea alba Root Extracts and Their Biological Properties

“…Considering the size measurements of AuNPs from Nymphaea alba root extracts from the Danube Delta under different reaction conditions, an order can be established depending on the technique used: DLS > TEM > XRD. This fact is also not unusual for nanoparticles synthesized with plant extracts [87][88][89][90]. The observed crystallite size and particle core size of AuNPR n were much smaller than the respective measured hydrodynamic size, which is due to the fact that the hydrodynamic diameter also reproduces the presence of the coating of biomolecules from the root extracts around the core of the nanoparticles.…”