Near-infrared light activatable nanoplatform for proteins labeling, enrichment and visualization in living systems

The study of target proteins is crucial for understanding molecular interactions and developing analytical platforms, therapeutic agents and functional tools. Herein, we present a novel nanoplatform activated by near-infrared (NIR) light for triple-modal proteins study, which enabling target protein labeling, enrichment and visualization. Azido-naphthalimide-coated upconversion nanoparticles (UCNPs) serve as NIR light-responsive nanoplatforms, showing promising applications in studying interactions between various bioactive molecules and proteins in living systems. Under NIR light irradiation, azido-naphthalimides are activated by ultraviolet (UV) and blue light emitted from UCNPs and the resulting amino-naphthalimides intermediate not only crosslink nearby target proteins but also enable imaging performance. We demonstrate that this nanoplatform is capable of selective protein labeling and imaging in complex protein environments, achieving specific labeling and imaging of both intracellular and extracellular proteins in mammalian cells as well as bacteria. Furthermore, in vivo protein labeling has been achieved using this novel NIR light-activatable nanoplatform. This technique will open new avenues for discoveries and mechanistic interrogation in chemical biology. We present a novel nanoplatform activated by near-infrared (NIR) light for triple-modal proteins study, which enabling target protein labeling, enrichment and visualization.