Plasmonic colloidal Au nanoparticles in DMSO: a facile synthesis and characterisation

Area of Science:

• Nanotechnology
• Materials Science
• Chemistry

Background:

• Plasmonic gold nanoparticles (Au NPs) are crucial in various applications.
• Existing synthesis methods often require specific solvents or conditions.
• Developing biocompatible Au NPs in alternative media is essential for broader applications.

Purpose of the Study:

• To establish a new, stable synthesis pathway for plasmonic gold nanoparticles (Au NPs).
• To produce Au NPs in a biocompatible medium, specifically dimethyl sulfoxide (DMSO).
• To evaluate the characteristics, stability, and potential applications of the synthesized Au NPs.

Main Methods:

• Modified Turkevich synthesis at room temperature using sodium citrate.
• Characterization using scanning electron microscopy (SEM), UV-vis absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), Raman scattering, and Fourier-transform infrared (FTIR) spectroscopy.
• Stability testing and evaluation for Surface-Enhanced Raman Spectroscopy (SERS) and antibacterial activity.

Main Results:

• A stable colloidal suspension of Au NPs in DMSO was successfully synthesized.
• The Au NPs exhibited a mean size of approximately 15 nm with low size distribution.
• The nanoparticles remained stable for months without aggregation and demonstrated utility as SERS substrates.
• Tested Au NPs showed no significant antibacterial activity against common bacteria.

Conclusions:

• The modified Turkevich method provides a viable route for synthesizing stable Au NPs in DMSO.
• The stabilization mechanism in DMSO is comparable to that in aqueous solutions.
• The synthesized Au NPs are suitable for SERS applications and possess favorable biocompatibility due to minimal antibacterial effects.