Intracellular optical probing with gold nanostars

Area of Science:

• Biophotonics
• Nanotechnology
• Cell Biology

Background:

• Gold nanostars are valuable tools in biophotonics and theranostics.
• Understanding their fate in the endolysosomal system is crucial for biotechnological applications.

Purpose of the Study:

• To investigate the intracellular behavior of gold nanostars in living cells.
• To correlate nanostar morphology with their endolysosomal processing and optical properties.

Main Methods:

• Synthesis of unlabeled, non-targeted gold nanostars.
• Cellular uptake studies in 3T3 and HCT-116 cell lines.
• Analysis of intracellular agglomeration and optical field enhancement using surface-enhanced Raman scattering (SERS).

Main Results:

• Gold nanostars undergo cell line-dependent agglomeration within the endolysosomal system.
• Agglomerated nanostars create greater local optical field enhancement compared to individual nanostars or spherical nanoparticles.
• SERS analysis revealed that intracellular processing is linked to nanostar morphology and protein corona interactions, influenced by hydrophobic interactions at the gold surface.

Conclusions:

• Gold nanostars are effective for label-free vibrational characterization due to consistent SERS signal strength.
• Their optical properties and intracellular processing are tunable via morphological control.
• Gold nanostars show promise as optical bionanosensors and therapeutic agents.