Chemotherapies for cancer remedy typically suffer from poor targeting capacity and critical side-effects. To improve the remedy efficiency and lower unwanted effects, photoactivatable chemotherapy has been not too long ago proposed for precise cancer remedy with higher spatiotemporal resolution. On the other hand, most photoactivatable prodrugs demand decoration by stoichiometric photo-cleavable groups, which are only responsive to ultraviolet irradiation and endure from low reaction efficiency. To tackle these challenges, we herein propose a bioorthogonal photo-catalytic activation approach with riboflavin because the catalyst for in situ transformation of prodrug dihydrochelerythrine (DHCHE) prodrug into anti-cancer drug chelerythrine (CHE), which can effectively kill cancer cells and inhibit in vivo tumor development under light irradiation. Meanwhile, the photo-catalytic transformation from DHCHE into CHE was in situ monitored by green-to-red fluorescence conversion, which is usually employed for precise control on the therapeutic dose. The photocatalytic mechanism was also fully explored by indicates of density functional theory (DFT) calculations. We think this imaging-guided bioorthogonal photo-catalytic activation technique is promising for cancer chemotherapy in clinical applications. 7-Deaza-2′-deoxy-7-iodoadenosine Chemscene 109704-53-2 manufacturer PMID:24065671