Efficient, Near‐Infrared Light‐Induced Photoclick Reaction Enabled by Upconversion Nanoparticles

• Published in: Advanced functional materials 2023-12, Vol.33 (50), p.n/a
• Main Authors: Fu, Youxin, Wu, Kefan, Alachouzos, Georgios, Simeth, Nadja A., Freese, Thomas, Falkowski, Michal, Szymanski, Wiktor, Zhang, Hong, Feringa, Ben L.
• Format: Article
• Language: English
• Subjects: Biocompatibility; Chemical reactions; Chemical synthesis; Conjugation; Customization; Energy transfer; Light; Light irradiation; Materials science; Medical imaging; Nanoparticles; Near infrared radiation; near‐infrared light; phenanthrenequinone; photochemistry; photoclick chemistry; Sandwich structures; Ultraviolet radiation; Upconversion; upconversion nanoparticles
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202306531

Photoclick reactions combine the selectivity of classical click chemistry with the high precision and spatiotemporal control afforded by light, finding diverse utility in surface customization, polymer conjugation, photocross‐linking, protein labeling, and bioimaging. Nonetheless, UV light, pivotal in prevailing photoclick reactions, poses issues, especially in biological contexts, due to its limited tissue penetration and cell‐toxic nature. Herein, a reliable and versatile strategy of activating the photoclick reactions of 9,10‐phenanthrenequinones (PQs) with electron‐rich alkenes (ERAs) with near infrared (NIR) light transduced by spectrally and structurally customized upconversion nanoparticles (UCNPs) is introduced. Under NIR irradiation, the UCNPs become UV/blue nanoemitters uniformly distributed in the reaction system. Enabled by the customized UCNPs, 800 or 980 nm light effectively activates the photocycloaddition reactions via radiative energy transfer in both general and triplet–triplet energy transfer (TTET)‐mediated PQ‐ERA systems. In particular, the novel sandwich structure UCNPs achieve the click reaction with up to 76% production yield in 10 min under NIR light irradiation. Meanwhile, the tricky side effect of photoclick product absorption‐induced quenching is successfully circumvented from the fine‐tuning of the upconversion spectrum. Moreover, through‐tissue irradiation experiments, the authors show that the UCNP‐PQ‐ERA reaction unlocks the full potential of photoclick reactions for in vivo applications. A reliable and versatile strategy to near‐infrared (NIR) light‐induced 9,10‐phenanthrenequinones (PQs) ‐ electron‐rich alkenes (ERAs) photoclick reactions enabled by upconversion nanoparticles (UCNP) was presented. By capitalizing on favorable absorption and emission spectra overlaps between PQs/photosensitizers and UCNPs, the emitted light from UCNPs effectively triggers PQ‐ERA reaction. Additionally, successful in vivo application is demonstrated via deep tissue penetration.