Photocontrolled DNA Origami Assembly by Using Two Photoswitches.

Stimuli-responsive switching molecules have been widely investigated for the purpose of the mechanical control of biomolecules. Recently developed arylazopyrazole (AAP) shows photoisomerization activity, displaying a faster response to light-induced conformational changes and unique absorption spectral properties compared with those of conventionally used azobenzene. Herein, it is demonstrated that AAP can be used as a photoswitching molecule to control photoinduced assembly and disassembly of DNA origami nanostructures. An AAP-modified DNA origami has been designed and constructed. It is observed that the repeated assembly and disassembly of AAP-modified X-shaped DNA origami and hexagonal origami with complementary strands can be achieved by alternating UV and visible-light irradiation. Closed and linear assemblies of AAP-modified X-shaped origami were successfully formed by photoirradiation, and more than 1 µm linear assemblies were formed. Finally, it is shown that the two photoswitches, AAP and azobenzene, can be used in tandem to independently control different assembly configurations by using different irradiation wavelengths. AAP can extend the variety of available wavelengths of photoswitches and stably result in the assembly and disassembly of various DNA origami nanostructures.