Bi₂O₃ nano-flakes as a cost-effective antibacterial agent

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Bismuth oxide (Bi₂O₃) is a versatile material with established applications.
• Nanoscale bismuth oxide exhibits unique properties due to high surface-area-to-volume ratios.
• Exploring novel synthesis methods for nanomaterials is crucial for new applications.

Purpose of the Study:

• To synthesize bismuth oxide (Bi₂O₃) nano-flakes using a novel, assistance-free pulsed laser ablation method.
• To characterize the synthesized Bi₂O₃ nano-flakes.
• To evaluate the antimicrobial efficacy of the Bi₂O₃ nano-flakes.

Main Methods:

• Pulsed laser ablation in liquids (PLAL) of pure bismuth needles in de-ionized water.
• High fluence irradiation (∼160 J cm⁻²) to promote two-dimensional growth.
• Atomic force microscopy (AFM) for flake dimensions.
• Selected area electron diffraction (SAED) and Raman spectroscopy for phase identification.

Main Results:

• Successfully synthesized Bi₂O₃ nano-flakes with lateral dimensions around 1 μm and thickness of 47.0 ± 12.7 nm.
• Confirmed the presence of α- and γ-Bi₂O₃ phases.
• Demonstrated complete inhibition of Gram-positive (MRSA) and Gram-negative (MDR-EC) bacteria at approximately 50 ppm concentration.

Conclusions:

• Pulsed laser ablation in liquids is an effective method for producing Bi₂O₃ nano-flakes without external assistance.
• The synthesized Bi₂O₃ nano-flakes possess significant antimicrobial activity.
• These findings suggest potential applications of Bi₂O₃ nano-flakes in antimicrobial therapies.