SERS/NIR-II Optical Nanoprobes for Multidimensional Tumor Imaging from Living Subjects, Pathology, and Single Cells and Guided NIR-II Photothermal Therapy

Molecular imaging-guided precision photothermal therapy has shown tremendous potential for invasively thermal ablation with solid tumors. However, it is still a pressing clinical need to develop precise and deep-tissue multi-scale imaging technologies easily integrated into a single system to boost accurate photothermal treatments. Herein, a SERS/NIR-II optical nanoprobe assembled by gold nanostars, Raman molecular tags, and silver sulfide quantum dots through silica bridges (named AuDAg2S) is reported that allows the combination of the fingerprint-style surface-enhanced Raman scattering (SERS) imaging and second region near-infrared (NIR-II) in-depth biological fluorescence imaging. It can also yield strong localized surface plasmon resonance for a satisfactory photothermal conversion efficiency of 67.1% at 1064 nm to effectively kill CT26 colon cancer cells. Moreover, the AuDAg2S nanoprobes can enhance the detection sensitivity up to the picomolar level and increase the depth of the NIR-II fluorescence signal up to 1 cm under the excitation of the near-infrared laser. As a result, the AuDAg2S nanoprobes can achieve multidimensional tumor imaging in levels of living subjects, histology, and single cell, and further guided deep NIR-II photothermal anti-tumor therapy in vivo. This work may offer a promising approach for SERS/NIR-II whole optical imaging for deep tumor photothermal treatment in future clinical applications.

Automated summary

This study reports a molecular imaging technology using nanoprobe that enables simultaneous Raman scattering imaging and near-infrared fluorescence imaging, achieving multi-scale tumor imaging. The nanoprobes have high photothermal conversion efficiency and deep detection sensitivity, guiding deep photothermal anti-tumor therapy in vivo.