Environmentally Friendly Improvement of Plasmonic Nanostructure Functionality towards Magnetic Resonance Applications

Area of Science:

• Materials Science
• Nanotechnology
• Physical Chemistry

Background:

• Plasmonic nanostructures are crucial for biosensing, catalysis, photovoltaics, and biomedicine.
• Pulsed laser ablation in liquids (PLAL) offers contamination-free synthesis of nanoparticles (NPs).
• PLAL allows controlled production of hybrid NPs, enhancing functionality, but merging metallic and semiconductor features remains challenging.

Purpose of the Study:

• To synthesize hybrid gold-silicon (AuSi) nanoparticles with tunable compositions.
• To explore novel modalities for AuSi NP synthesis using ultrashort laser ablation.
• To investigate the properties and potential applications of these novel hybrid nanostructures.

Main Methods:

• Ultrashort pulsed laser ablation of bulk gold in water containing silicon nanoparticles (Si NPs).
• Controlled variation of initial Si NP concentration to tune the Au/Si atomic ratio.
• Characterization of the resulting hybrid AuSi nanoparticles and their properties.

Main Results:

• Successfully synthesized hybrid AuSi NPs with tunable Au/Si atomic ratios (0.5–3.5) by adjusting Si NP concentration.
• Demonstrated that silicon content is mass-dependent and relatively insensitive to laser fluence.
• Achieved a high concentration of paramagnetic defects (2.2 × 10^18 spin/g) in the polycrystalline plasmonic NPs.

Conclusions:

• The developed method provides a facile and scalable route for synthesizing functional AuSi hybrid nanostructures.
• These hybrid NPs exhibit promising properties for applications in optical and magnetic resonance imaging, biosensing, and cancer theranostics.
• The high concentration of paramagnetic defects opens avenues for multimodal imaging and therapeutic applications.