Synthesis and Characterization of Ligand-Stabilized Silver Nanoparticles and Comparative Antibacterial Activity against E. coli

Abstract

Silver is a well-established antimicrobial agent. Conjugation of organic ligands with silver nanoparticles has been shown to create antimicrobial nanoparticles with improved pharmacodynamic properties and reduced toxicity. Twelve novel organic ligand functionalized silver nanoparticles (AgNPs) were prepared via a light-controlled reaction with derivatives of benzothiazole, benzoxazine, quinazolinone, 2-butyne-1,4-diol, 3-butyne-1-ol, and heptane-1,7-dioic. UV-vis, Fourier-transform infrared (FTIR) spectroscopy, and energy-dispersive X-ray (EDAX) analysis were used to confirm the successful formation of ligand-functionalized nanoparticles. Dynamic light scattering (DLS) revealed mean nanoparticle diameters between 25 and 278 nm. Spherical and nanotube-like morphologies were observed using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Seven of the twelve nanoparticles exhibited strong antimicrobial activity and five of the twelve demonstrated significant antibacterial capabilities against E. coli in a zone-of-inhibition assay. The synthesis of functionalized silver nanoparticles such as the twelve presented is critical for the further development of silver-nanoconjugated antibacterial agents.

Progress of Section “Biochemistry” in 2022

“…More than 1350 papers were published in 2022 on anti-infectives. Among them, I will highlight an interesting review on photodynamic therapy for the inactivation of Acinetobacter baumannii biofilms [ 40 ], a computational approach for designing anti- Staphylococcus aureus agents by targeting transcription [ 41 ], antimicrobial peptides showing broad-spectrum activity against Pseudomonas aeruginosa [ 42 ], silver nanoparticles for delivery of antibiotics against Escherichia coli infections [ 43 ], as well as a comprehensive review regarding the nanoparticles for antibacterial delivery [ 44 ].…”

Ursolic acid: biological functions and application in animal husbandry

“…Antibiotic resistance and the emergence of superbugs have become serious public health problems in both human and veterinary medicine. To treat infections caused by multi-drug resistant pathogens, many different strategies have been used, including phages ( 76 ), antimicrobial peptides ( 77 ), metal nanoparticles ( 78 ), and plant-derived compounds--polyphenols ( 79 ), flavonoids ( 80 ), terpenoids ( 81 ), plant essential oils ( 82 ), and alkaloids ( 83 ). Traditional Chinese Medicine and Ayurveda have also been used in health care and disease prevention in ancient China and Egypt ( 84 ).…”