High‐Specificity In Vivo Tumor Imaging Using Bioorthogonal NIR‐IIb Nanoparticles

Abstract Lanthanide‐based NIR‐IIb nanoprobes are ideal for in vivo imaging. However, existing NIR‐IIb nanoprobes often suffer from low tumor‐targeting specificity, limiting their widespread use. Here the application of bioorthogonal nanoprobes with high tumor‐targeting specificity for in vivo NIR‐IIb luminescence imaging and magnetic resonance imaging (MRI) is reported. These dual‐modality nanoprobes can enhance NIR‐IIb emission by 20‐fold and MRI signal by twofold, compared with non‐bioorthogonal nanoprobes in murine subcutaneous tumors. Moreover, these bioorthogonal probes enable orthotopic brain tumor imaging. Implementation of bio‐orthogonal chemistry significantly reduces the nanoprobe dose and hence cytotoxicity, providing a paradigm for real‐time in vivo visualization of tumors.