Hyperspectral Darkfield Microscopy of PEGylated Gold Nanoparticles Targeting CD44-Expressing Cancer Cells

We present a new hyperspectral darkfield imaging system with a scanned broadband supercontinuum light source. We observed the specific attachment of the functionalized gold plasmonic nanoparticles (AuNPs) targeting CD44⁺ human breast cancer cells by conventional and by proposed hyperspectral darkfield microscopy. This wide-field and low phototoxic hyperspectral imaging system has been successful for performing spectral threedimensional (3D) localization and spectroscopic identification of CD44-targeted PEGylated AuNPs in fixed cell preparations. Such spatial and spectral information is essential for the improvement of nanoplasmonic-based imaging, disease detection and treatment in complex biological environment. Presented system capability for 3D NP tracking will also enable investigation of specific subcellular activity with the use of NPs as spectral sensors.