All‐Visible Light‐Activated Photoswitching of Diarylethenes via Direct Triplet Sensitization From Low‐Toxicity ZnSe/ZnS Quantum Dots

ABSTRACT Developing all‐visible light‐activated diarylethene (DAE) molecular photoswitches hold great promise for high‐resolution bioimaging and smart photoresponsive materials. Herein, we demonstrate that a bicomponent system comprising low‐toxicity ZnSe/ZnS quantum dots (QDs) and carboxylated DAEs achieves all‐visible light‐activated photoswitching through a single‐step triplet energy transfer (TET) in both organic and aqueous media. The photoswitching process exhibits reversible photoisomerization and fatigue resistance over multiple cycles under alternating 405 and 590 nm irradiation. The photocyclization quantum yield ( = 55%) of DAEs in our design represents a record‐high efficiency of DAEs under visible light activation compared with previously reported QD‐sensitized and organic‐sensitized systems. The high yield stems from the enhanced quality and a large molar extinction coefficient of ZnSe/ZnS QDs and efficient TET from ZnSe/ZnS QDs to dynamically enchored DAEs. Importantly, a biocompatible photoswitching system was constructed through the self‐assembly of amphiphilic 1,2‐Distearoyl‐sn‐glycero‐3‐phosphoethanolamine‐polyethylene glycol with the mixture of DAEs and ZnSe/ZnS QDs, enabling efficient and reversible photoisomerization of DAEs under all‐visible light irradiation in aqueous media. Our strategy not only paves the way for advancing the development of all‐visible light‐activated optoelectronic devices but also creates new opportunities in further biological applications.