Metal enhanced fluorescence solution-based sensing platform 2: fluorescent core-shell Ag@SiO2 nanoballs.

Area of Science:

• Nanotechnology
• Materials Science
• Biophotonics

Background:

• Core-shell nanoparticles offer unique optical properties.
• Metal-enhanced fluorescence (MEF) utilizes plasmonic nanoparticles to boost fluorophore emission.
• Developing robust and versatile MEF nanostructures is crucial for advanced bio-imaging.

Purpose of the Study:

• To synthesize and characterize monodisperse silver-silica core-shell nanoparticles (MEF nanoballs) with tunable shell thicknesses.
• To demonstrate the metal-enhanced fluorescence effect using these nanoballs.
• To explore the potential of MEF nanoballs in biological applications like cellular imaging and sensing.

Main Methods:

• Synthesis of monodisperse silver nanoparticles as cores.
• Coating silver cores with silica shells of varying thicknesses (up to 35 nm).
• Doping silica shells with fluorophores (e.g., Rhodamine 800).
• Fabrication of control samples (fluorescent nanobubbles) by etching silver cores.
• Characterization using electron microscopy and optical spectroscopy.

Main Results:

• Successfully developed monodisperse silver-silica core-shell nanoparticles (MEF nanoballs).
• Demonstrated significant fluorescence enhancement due to the silver core, confirming the MEF effect.
• Showcased potential for near-infrared emission using Rhodamine 800 for biological applications.
• Control samples confirmed the necessity of the silver core for fluorescence enhancement.

Conclusions:

• MEF nanoballs are effective platforms for enhancing fluorescence through plasmonic effects.
• The tunable silica shell allows for controlled incorporation of fluorophores and tailoring of properties.
• MEF nanoballs show significant promise for advanced cellular imaging and sensitive solution-based sensing applications.