Green synthesized silver nanoparticles: Optimization, characterization, antimicrobial activity, and cytotoxicity study by hemolysis assay

Nida Liaqat; Nazish Jahan; Khalil-Ur-Rahman; Tauseef Anwar; Huma Qureshi

doi:10.3389/fchem.2022.952006

Green synthesized silver nanoparticles: Optimization, characterization, antimicrobial activity, and cytotoxicity study by hemolysis assay

Front Chem. 2022 Aug 29:10:952006. doi: 10.3389/fchem.2022.952006. eCollection 2022.

Authors

Nida Liaqat^{1

2}, Nazish Jahan¹, Khalil-Ur-Rahman³, Tauseef Anwar⁴, Huma Qureshi⁵

Affiliations

¹ Department of Chemistry, University of Agriculture, Faisalabad, Pakistan.
² Department of Chemistry, Rawalpindi Women University, Rawalpindi, Pakistan.
³ Department of Biochemistry, University of Agriculture, Faisalabad, Pakistan.
⁴ Department of Botany, The Islamia University of Bahawalpur, Bahawalpur, Pakistan.
⁵ Department of Botany, University of Chakwal, Chakwal, Pakistan.

Abstract

Green nanotechnology has emerged as a viable option for the production of nanoparticles. The purpose of the current investigation was to synthesize silver nanoparticles (AgNPs) using Eucalyptus camaldulensis and Terminalia arjuna extracts, as well as their combinations, as green reducing and capping agents. The parameters (concentration of silver nitrate solution and plant extract, time, pH, and temperature) were optimized for maximal yields, regulated size, and stability of silver nanoparticles. The ultraviolet-visible spectrophotometer (UV-Vis) and the surface plasmon resonance band (SPR) were used to validate the synthesis of AgNPs. The size, shape, and stability of nanoparticles were assessed using a zeta analyzer and a scanning electron microscope (SEM). The biomolecules responsible for the reduction of silver ion (Ag⁺) and the stability of silver nanoparticles generated with the plant extracts were identified using Fourier-transform infrared spectroscopy (FTIR). The agar-well diffusion method was used to test the antimicrobial activity of biosynthesized nanoparticles against Bacillus subtilis, Staphylococcus aureus, Pasteurella multocida, and Escherichia coli. When 1 mM of silver nitrate (AgNO₃) was added to plant extracts and incubated for 60 min at 75°C in a neutral medium, maximum nanoparticles were produced. Biosynthesized silver nanoparticles were stable, spherical, and monodispersed according to zeta potential and scanning electron microscopy. Silver nanoparticles synthesized with combination 2 and T. arjuna showed the highest zone of inhibition (16 mm) against B. subtilis while combination 3 showed the largest zone of inhibition against S. aureus (17 ± 0.8). It was concluded that greenly produced silver nanoparticles showed good antibacterial activity while causing negligible cytotoxicity.

Keywords: UV-visible spectrophotometer; antibacterial activity; dynamic light scattering; green nanotechnology; silver nanoparticles; zeta potential.