Fluorescence-surface enhanced Raman scattering co-functionalized gold nanorods as near-infrared probes for purely optical in vivo imaging

Gold nanorods (GNRs) have been widely used for bio-imaging. However, GNRs assisted optical in vivo deep tissue imaging is severely restricted due to signal attenuation, low contrast, complex process or low real-timing. To overcome these problems, we functionalized GNRs with both near-infrared (NIR) fluorescence and surface enhanced Raman scattering (SERS) and utilized these co-functionalized GNRs for purely optical in vivo imaging of live mice. Our proposed technology has the combined advantages of high real-timing, high imaging contrast and deep detection ability. The distribution and excretion of intravenously injected GNRs in deep tissues of live mice were observed in vivo for the first time through purely optical imaging. We also demonstrated successfully in vivo biomedical applications of the co-functionalized GNRs to sentinel lymph node (SLN) mapping and tumor targeting of mice. The present technology has great future potentials for disease diagnosis and clinical therapies.