Benzoheterocycles are extensively utilized as drug-like core scaffolds and have been effectively integrated into DNA-encoded chemical library technology to facilitate high-throughput hit discovery. Li and co-workers successfully synthesized four types of DNA-conjugated benzoheterocycles, including benzothiazoles 27, under light-promoted conditions with a broad substrate scope (Scheme 3). The authors proposed that the reaction proceeds via the same mechanism previously established (Scheme 2) , with (p-TolS)2 13 serving as an external photosensitizer in this instance. The development of novel bioorthogonal reactions that enable the sensitive and efficient detection of 5-formylcytidine RNA in nucleic acids, both in vitro and in vivo, remains a significant challenge. To address this, a blue LED-triggered, catalyst-free photo-click condensation was employed to selectively label 5-formylcytidine with 2-aminothiophenol, resulting in the formation of the fluorogenic 5-(benzothiazol-2-yl) cytidine 28 (Scheme 3) . Scheme 3. Synthesis of DNA-conjugated benzothiazoles 27 and 5-(benzothiazol-2-yl) cytidine 28.