Characterization and antibacterial activity of silica-coated bismuth (Bi@SiO2) nanoparticles synthesized by pulsed laser ablation in liquid

• Published in: Optik (Stuttgart) 2023-02, Vol.273, p.170453, Article 170453
• Main Authors: Hassan, Sally S., Hubeatir, Kadhim A., Al-Haddad, Raad M.S.
• Format: Article
• Language: English
• Subjects: Antibacterial activity; Bi@SiO2 CSNPs; Gram positive and Gram negative bacteria; Nd:YAG laser; Pulsed laser ablation in liquid
• ISSN: 0030-4026; 1618-1336
• DOI: 10.1016/j.ijleo.2022.170453

This study investigates, for the first time, the characteristics and antibacterial activity of elemental bismuth nanoparticles (Bi NPs) synthesized using pulsed laser ablation in liquid (PLAL) coated with silica using the alcohol-ammonia-Tetraethyl orthosilicate (TEOS) method, producing Bi@SiO2 core–shell NPs, and evaluated the effect of Centrifuge selection on the resultant NPs. The synthesized Bi@SiO2 NPs were characterized using Ultraviolet-Visible (UV-Vis) spectroscopy, energy-dispersive X-ray spectroscopy (EDXS), X-ray diffraction spectroscopy (XRD), and transmission electron microscopy (TEM). UV-Vis spectra measurements confirmed the successful coating of NPs and demonstrated that silica coating of Bi NPs increases the stability of the colloidal solution. EDXS and XRD analysis confirmed the preparation of pure metallic Bi NPs coated by SiO2. TEM images showed that Bi NPs were adequately coated and that the thickness of the silica shell increased with the amount of TEOS used. The antibacterial activity of the coated NPs against E. coli and S. aureus was subsequently assessed using the agar diffusion method. Bi@SiO2 NPs exhibited remarkable antibacterial activity, with an increase in efficacy and a higher potency against E. coli compared to uncoated Bi NPs. The diameter of the inhibition zones increased with the silica shell thickness and the NPs’ concentration.