Aptamer-Functionalized, Ultra-Small, Monodisperse Silica Nanoconjugates for Targeted Dual-Modal Imaging of Lymph Nodes with Metastatic Tumors

A dual-modal imaging probe based on size-controlled silica nanoconjugates was synthesized for targeted imaging of lymph nodes by means of both PET and near infrared fluorescence techniques. 20 nm nanoconjugates (see scheme) functionalized with an aptamer (green triangles) that targets 4T1 breast cancer cells improved the detection efficiency of sentinel lymph nodes with metastatic tumors.