Active Double-Layered Films Enriched with AgNPs in Great Water Dock Root and Pu-Erh Extracts

A novel, eco-friendly, and biocompatible method was applied to form silver nanoparticles (AgNPs) in great water dock (Lapathi radix) (KB) and pu-erh (Camellia sinensis) (PE) extracts. The surface plasma resonance peak of green synthesized AgNPs at 451.8 nm for AgNPs+KB and 440.8 nm for AgNPs+PE was observed via spectral analysis of UV absorbance. In this study, double-layered biopolymer films (FUR/CHIT+HGEL) with AgNPs incorporated in KB solution (AgNPs+KB) and AgNPs in PE solution (AgNPs+PE), were successfully prepared using the casting method. The SEM, XRD, zeta potential and size analyses confirmed the presence of AgNP in the films. The addition of AgNPs in plant extracts improved antimicrobial and antioxidant activity and thermal stability, whereas WVTR experienced a decrease. The nanocomposite films’ orange-brown colour may aid in the protection of food products against UV rays. The composite films demonstrated antibacterial activity against food-borne pathogens and may offer potential in food packaging applications.

Ag nanoparticle-decorated SiO2@TiO2 hierarchical microspheres improve the efficiency of dye-sensitized solar cells

SiO2@TiO2-Ag (STA) microspheres decorated with Ag nanoparticles (Ag NPs) were prepared and assembled into the photoanode. The photoanode composed of STA microspheres and TiO2 nanoparticles (P25) was prepared by doctor blade method. UV-vis measurement indicates that the introduction of a few STA microspheres observably enhance the light scattering and capturing ability of the photoanode. The photoelectric conversion efficiency of the DSSCs with 2wt% STA photoanode increased to 7.4% from 4.3% comparing with pure P25 TiO2 nanoparticles. The configuration DSSCs have the maximum short circuit current density (Jsc) of 16.0 mA cm− 2 and open circuit voltage (Voc) of 0.780 V, which are significantly higher than the pure TiO2 DSSCs. The significant improvement of the DSSCs performance can be due to the synergistic effect of the superior light scattering of STA and the localized surface plasma resonance (LSPR) effect of Ag NPs modified on the microspheres surface.

Green Synthesis of Silver Nanoparticles Using Flower Extract of Hemigraphis colorata as Reducing Agent and its Biological Activity

Green synthesis of silver nanoparticles (Ag NPs) was performed using flower extract of Hemigraphis colorata (H. Colorata). Synthesized nanoparticles were characterized by UV-Visible Spectrophotometer (UV-Vis), Fourier Transform Infrared (FT-IR), Scanning Electron Microscope (SEM), and Transmission Electron Microscope (TEM-SAED). , The crystalline nature of the sample was examined by an X-ray diffraction study (XRD). The UV-Visible spectrum showed surface plasma resonance (SPR) at 360 nm revealed the formation of nanoparticles, SEM and TEM exhibited spherical shape particles with an average size between 10-20 nm. The valuation of the antibacterial and antifungal study revealed its efficiency in killing bacteria and fungi.

An Investigation on the Antiproliferative and Antibacterial Activity of Silver Nanoparticles of Quercus infectoria and Daucus carota subsp sativum

Plant mediated fabrication of nanoparticles and nanomaterials are gaining momentum as it is eco-friendly and cost-effective. In the present study, we synthesis of Silver nanoparticles using aqueous extract of Quercus infectoria nuts and Daucus carota subsp sativum leaves. The surface plasma resonance at 417 and 450 nm for Q. infectoria and D. carota respectively confirmed the formation of AgNPs. Scanning Electron Microscopic (SEM) confirmed the spherical shape of the nanoparticles, which had an average size of 67.5 nm and 49.2 nm for Q. infectoria nanoparticles (QAgNPs)and D. carota nanoparticles (DAgNPs). The elemental composition by Energy-Dispersive X-ray analysis of the nanoparticle showed an atomic percentage of silver as 73.64 % and 75.93% for Q. infectoria and D. carota.FT- IR analysis of the plant extracts and synthesized silver nanoparticles showed the presence of various functional groups. The total antioxidant activity of QAgNPs was 81.18% and that of DAgNPs was 73.36%. The QAgNPs and DAgNPs exhibited antibacterial activity against B. subtilis, E. coli and S. aureus. The percentage of cell viability for QAgNPs and DAgNPs assessed using HeLa cells was 21.1% and 6% respectively.