Detection and localization of gold nanoshells inside cells: near-field approximation

Area of Science:

• Nanotechnology
• Biomedical Optics
• Cancer Research

Background:

• Metal nanoparticles, like gold nanoshells (NSs), are crucial for applications such as cancer hyperthermia treatment.
• Gold NSs absorb laser energy, generating heat to destroy cancer cells while sparing healthy tissue due to the near-infrared (NIR) tissue optical window.

Purpose of the Study:

• To numerically demonstrate the capability of scanning near-optical microscopy (SNOM) for identifying gold NSs within biological cells.
• To establish the precision of SNOM in locating NSs at a specific near-field distance.

Main Methods:

• Development of an analytical approach utilizing the dyadic Green function in the near-field approximation.
• Numerical simulation to assess the localization accuracy of SNOM for gold NSs (100-150 nm diameter) within cells.

Main Results:

• The study provides a numerical validation that SNOM can accurately locate gold NSs inside cells.
• Localization was demonstrated to be effective at a particle-aperture distance of approximately 100 nm.

Conclusions:

• SNOM shows significant potential for identifying gold NSs within cellular environments, crucial for advancing targeted cancer therapies.
• These findings are expected to impact future research on nanoparticle-biological system interactions.