Physically targeting specific areas within a single live cell with high spatial resolution is an attractive approach for better understanding of cellular behavior. Cell endoscopy offers a promising tool for achieving site-specific access inside a single live cell. In conventional cell endoscopy, various probes, such as glass pipettes, glass fibers, nanowires, and nanotubes, are inserted into a cell, enabling optical studies, material delivery, electrochemistry, and other applications. Optical waveguide probes are increasingly popular due to their ability to easily direct and extract optical information from the cell.
Plasmon-based single live-cell nanowire endoscopy is a promising novel tool for understanding biological processes at the single-cell level. This technique enables highly sensitive sensing of Raman signals from specific areas within a single live cell with minimal invasiveness by utilizing the unique plasmonic properties of a metal nanowire as an endoscopic probe. This allows for the study of interactions such as those between DNA and fluorescence dye inside a nucleus, or the measurement of site-specific intracellular pH. Furthermore, this technique has great potential for developing intracellular material delivery systems by engineering the surface of nanowire probes. Here, we introduce novel approaches for intracellular material delivery by integrating functional organic and inorganic molecules with plasmonic nanowires.