Dual-Responsive Metabolic Precursor and Light-Up AIEgen for Cancer Cell Bio-orthogonal Labeling and Precise Ablation.

Metabolic glycoengineering of unnatural glycans with bio-orthogonal chemical groups and a subsequent click reaction with fluorescent probes have been widely used in monitoring various bioprocesses. Herein, we developed a dual-responsive metabolic precursor that could specifically generate unnatural glycans with azide groups on the membrane of targeted cancer cells with high selectivity. Moreover, a water-soluble fluorescent light-up probe with aggregation-induced emission (AIE) was synthesized, which turned its fluorescence on upon a click reaction with azide groups on the cancer cell surface, enabling special cancer cell imaging with low background signal. Furthermore, the probe can generate 1 O2 upon light irradiation, fulfilling its dual role as an imaging and therapeutic agent for cancer cells. Therefore, the concepts of the cancer-cell-specific metabolic precursor cRGD-S-Ac3 ManNAz and the AIE light-up probe are promising in bio-orthogonal labeling and cancer-specific imaging and therapy.