Single-cell photonic nanocavity probes.

Area of Science:

• Biophotonics
• Nanotechnology
• Cell Biology

Background:

• Photonic nanocavities offer unique optical properties for sensing applications.
• Integrating nanophotonics with live-cell imaging presents significant technical challenges.
• Developing biocompatible intracellular probes is crucial for advanced cellular studies.

Purpose of the Study:

• To demonstrate the first operation of photonic nanocavities within single biological cells.
• To develop a versatile nanobeam photonic crystal (PC) cavity as a cellular nanoprobe for sensing and control.
• To explore the potential for intracellular biomarker and biomolecule detection.

Main Methods:

• Fabrication of semiconductor nanocavity probes with embedded quantum dots (QDs).
• Characterization of probe photoluminescence (PL) and resonant photonic modes within cells.
• In vitro cell viability studies to assess cytotoxicity.
• In vitro label-free protein sensing experiments to detect streptavidin.

Main Results:

• Successful operation of PC nanocavities inside living cells.
• Probes exhibited minimal cytotoxicity and long-term stability within cells, supporting cell division.
• Demonstrated real-time, label-free detection of streptavidin, indicating potential for biomolecule sensing.
• High-quality resonant photonic modes were sustained within the cellular environment.

Conclusions:

• Photonic nanocavity probes represent a powerful new tool for intracellular sensing and control.
• The developed probes are biocompatible and suitable for long-term studies in live cells.
• This technology paves the way for novel research at the intersection of photonics and cell biology.
• Enables new possibilities for real-time monitoring of cellular processes and biomarkers.