Core-shell silver nanoparticles for optical labeling of cells

Area of Science:

• Nanotechnology
• Biotechnology
• Analytical Chemistry

Background:

• Silver nanoparticles (AgNPs) are valuable for optical applications.
• Developing stable, high-signal nanoparticles for biological labeling remains a challenge.

Purpose of the Study:

• To create robust core-shell nanoparticles for sensitive cell analysis.
• To utilize plasmon resonance for enhanced optical detection in flow cytometry and microscopy.

Main Methods:

• Modification of silver nanoparticles with thiol-terminated long chain thiols.
• Encapsulation of modified AgNPs with a silica shell.
• Functionalization with neutravidin and biotinylated antibodies for cell surface targeting.
• Analysis using flow cytometry and microscopy.

Main Results:

• Core-shell nanoparticles exhibited strong, depolarized light scattering upon plasmon resonance excitation.
• Nanoparticle labels demonstrated excellent stability in high salt concentrations.
• Labeled cells showed a two-order magnitude increase in scattering intensity compared to unlabeled cells.

Conclusions:

• Silica-shelled silver nanoparticles serve as effective, stable optical labels for cell analysis.
• The enhanced scattering signal significantly improves detection sensitivity in flow cytometry and microscopy.
• This nanotechnology offers a promising tool for high-resolution cell surface receptor analysis.