Bioorthogonal SERS Nanotags as a Precision Theranostic Platform for in Vivo SERS Imaging and Cancer Photothermal Therapy

Precise detection and effective treatment are crucial to prolong cancer patients' lives. Surface-enhanced Raman scattering (SERS) imaging coupled with photothermal therapy has been considered a precise and effective strategy for cancer theranostics. Nevertheless, Raman reporters employed in the literature usually possessed multiple shift peaks in the fingerprint region, which are overlapped with background signals from endogenous biological molecules. Herein, we fabricated a new kind of bioorthogonal Raman reporter and aptamer functionalized SERS nanotags. The SERS nanotags demonstrated a strong Raman signal at 2205 cm(-1) in the biologically Raman-silent region and recognized MCF-7 breast cancer cells for Raman imaging with high specificity. Laser irradiation induced serious toxicity of MCF-7 cells due to the excellent photothermal capability of the SERS nanotags. After intravenous administration of the SERS nanotags, tumor Raman spectral detection and mapping in living mice were successfully achieved. Further in vivo antitumor experiments manifested that the aptamer-modified SERS nanotags significantly restrained tumor growth after laser irradiation with 99% inhibition rate and good biocompatibility. These results clearly revealed that the SERS nanotags could serve as a novel and precise theranostic platform for in vivo cancer diagnosis and photothermal therapy.