Title: Synthesis, characterisation and antibacterial activity of magnetic Fe₃O₄-Ag nanomaterials

Authors: Anh Van Thi Le; Khang Viet Mai; Diep Ngoc Le; Chien Mau Dang; Dung My Thi Dang

Addresses: Institute for Nanotechnology, Community 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City, 700000, Vietnam; University of Science, 227 Nguyen Van Cu Street, Ward 4, District 5, Ho Chi Minh City, 700000, Vietnam; Vietnam National University Ho Chi Minh City (VNUHCM), Ho Chi Minh City, 700000, Vietnam ' Institute for Nanotechnology, Community 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City, 700000, Vietnam; Vietnam National University Ho Chi Minh City (VNUHCM), Ho Chi Minh City, 700000, Vietnam ' Institute for Nanotechnology, Community 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City, 700000, Vietnam; Vietnam National University Ho Chi Minh City (VNUHCM), Ho Chi Minh City, 700000, Vietnam ' Institute for Nanotechnology, Community 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City, 700000, Vietnam; Vietnam National University Ho Chi Minh City (VNUHCM), Ho Chi Minh City, 700000, Vietnam ' Institute for Nanotechnology, Community 6, Linh Trung Ward, Thu Duc City, Ho Chi Minh City, 700000, Vietnam; Vietnam National University Ho Chi Minh City (VNUHCM), Ho Chi Minh City, 700000, Vietnam

Abstract: Fe₃O₄-Ag nanomaterials were synthesised by a simple and economical method using Vietnamese green tea extract at room temperature. The green tea extract acts as a reducing agent for reducing silver and a stabiliser of the nanomaterials. Characteristic analysis of the nanoparticles was done using techniques including field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), and Fourier-transform infrared (FTIR) spectroscopy. The magnetic properties of the synthesised nanoparticles were measured by a vibrating sample magnetometer (VSM). The antibacterial effect of the nanomaterials was studied by determining the minimum inhibitory concentration (MIC) values on Escherichia coli (E. coli) and by FESEM images of bacterial cell membrane morphology. The Fe₃O₄-Ag nanomaterials in this study had a particle size of 20-30 nm, which included the Ag shell. They had a high crystalline structure with a spherical shape, and they were superparamagnetic. The MIC value of the Fe₃O₄-Ag nanomaterial on E. coli was about 400 μM/mL, and FESEM images revealed multiple lesions on the cell membrane. The results showed the potential development of magnetic nanomaterials based on friendly environmental synthesis.

Keywords: Fe₃O₄-Ag ; Vietnamese green tea; magnetic nanomaterials; antibacterial activity; E. coli.

DOI: 10.1504/IJNT.2024.146464

International Journal of Nanotechnology, 2024 Vol.21 No.7/8/9/10/11/12, pp.571 - 583

Published online: 30 May 2025 *

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