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

Abstract

This study describes a simple green method for the synthesis of Limnophila rugosa leaf-extract-capped silver and gold nanoparticles without using any expensive toxic reductant or stabilizer. The noble metal nanoparticles were characterized by Fourier transform infrared (FTIR) microscopy, powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray analysis (EDX), high-resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED), and dynamic light scattering (DLS) method. It has been found that the biosynthesized silver and gold nanoparticles are nearly spherical in shape with a mean particle size distribution of 87.5 nm and 122.8 nm, respectively. XRD and SAED patterns confirmed the crystalline nanostructure of the metal nanoparticles. FTIR spectra revealed the functional groups of biomolecules presented in the extract possibly responsible for reducing metallic ions and stabilizing formed nanoparticles. The biosynthesized metal nanoparticles have potential application in catalysis. Compared to previous reports, Limnophila rugosa leaf-extract-capped silver and gold nanoparticles exhibited a good catalytic activity in the reduction of several derivatives of nitrophenols including 1,4-dinitrobenzene, 2-nitrophenol, 3-nitrophenol, and 4-nitrophenol.

Honeybee pollen assisted biosynthesis of nanogold and its application as catalyst in reduction of 4-nitrophenol

“…It is proposed that, all reactants adsorbed on the catalyst surface and that the reaction takes place at active sites on the surface of catalyst. After that, the electron is transferred from the BH 4 - ion (donor) to the 4-NP/4-nitrophenolate (acceptor) through AuNPs (electron relay process) and the aqueous medium supplies the necessary quantity of H + ions for a total reduction of 4-NP to 4-AP [ 36 , 37 , 38 ]. Based on catalytic reduction data for 4-NP through various biomaterial-derived NPs, the current study was compared and presented in Table 1 .…”

“… Zingiber officinale Silver NPs 432 nm 5.28 ± 1.29 nm 2.9 × 10 −3 s −1 37 Limnophila rugosa leaves Silver NPs - 87.5 nm 3 . 1 × 10 −3 s −1 38 Cacumen platycladi Eggshell/Ag nanocomposites 420 nm 60 nm 1.56 min −1 39 Nephelium lappaceum peel AuNPs 563 nm 70–115 nm 19.089 × 10 −2 min −1 10 Calothrix ​algae AuNPs 550 nm 30–120 nm 72.4752 × 10 −3 min −1 13 Mangifera indica leaves AuNPs 530 nm 10–60 nm 5.679 × 10 −3 s −1 15 Citrus maxima AuNPs 535 nm 25.7 ± 10 nm 89.77 × 10 −3 min −1 31 Limnophila rugosa leaves AuNPs - 122.8 nm 2 . 8 × 10 −3 s −1 38 Rosa canina AuNPs 535 nm 26 nm 5.08 × 10 −2 min −1 40 Honeybee pollen AuNPs 530 nm 7–42 nm 59.17898 × 10 −3 min −1 current study …”

Green Synthesis of Metal and Metal Oxide Nanoparticles Using Different Plants’ Parts for Antimicrobial Activity and Anticancer Activity: A Review Article

“…In another report, Limnophila rugosa was used for the production of sphericalshaped gold nanoparticles with a mean particles' size distribution of 122 nm. Limnophila rugosa-capped gold nanoparticles showed tremendous catalytic activity in the reduction of different nitrophenols, e.g., 4-nitrophenol, 3-nitrophenol, and 1,4-nitrophenol [135]. Olajire, A.A. et al, reported the biological synthesis of spherical gold nanoparticles with a mean size of 18.85 ± 6.74 nm by utilizing aqueous leaf extract of Ananas comosus.…”

Efficacy of Gold Nanoparticles against Drug-Resistant Nosocomial Fungal Pathogens and Their Extracellular Enzymes: Resistance Profiling towards Established Antifungal Agents

“…Surface plasmon resonance (SPR) is a band that occurs on the surface of metallic nanomaterials. Noticeable peaks in the range of 530 to 540 nm correspond to the SPR of AuNPs [ 48 , 49 , 50 ]. UV-Vis analysis indicates the formation of AuNPs by the plant extract as per the characteristic wavelength observed around 530 nm ( Figure 3 ).…”

“…Surface plasmon resonance (SPR) is a band th nanomaterials. Noticeable peaks in the range of 530 AuNPs [48][49][50]. UV-Vis analysis indicates the format per the characteristic wavelength observed around 53 To further confirm the synthesis of AuNPs by M. piperita extract, FTIR was adopted (Figure 4).…”