Thermally Switchable Photoactivity in Azobenzene-Functionalized DNA Condensates

Area of Science:

• Materials Science
• Soft Robotics
• Biomedical Engineering
• DNA Nanotechnology

Background:

• Soft materials with environmental responsiveness are crucial for developing adaptive soft robotics and intelligent biomedical devices.
• Liquid-liquid phase separation (LLPS) is a key self-assembly mechanism for creating functional soft materials.
• Azobenzene derivatives are known photo-responsive molecules, but their integration into complex systems for tunable responses remains a challenge.

Purpose of the Study:

• To engineer novel soft materials with multimodal photothermal adaptability using DNA condensates.
• To investigate the temperature-dependent inversion of photo-response in azobenzene-conjugated DNA coacervates.
• To explore the potential of these responsive materials in advanced applications requiring precise spatiotemporal control.

Main Methods:

• Assembly of azobenzene-conjugated DNA condensates via liquid-liquid phase separation (LLPS).
• Characterization of material response to visible and ultraviolet (UV) light at varying temperatures.
• Analysis of the interplay between azobenzene photochemistry, DNA duplexes, and thermal properties (glass transition, melting temperatures).

Main Results:

• Demonstrated a striking temperature-dependent inversion of photo-response in the DNA condensates.
• At high temperatures, materials deformed with visible light and dissolved with UV light; at low temperatures, they reshaped with UV light and were inert to visible light.
• Attributed the bidirectional control to confined azobenzene photochemistry and isomer-dependent shifts in thermal transition temperatures.

Conclusions:

• Developed a novel platform of multi-responsive photofluids based on DNA condensates.
• Achieved exquisite spatiotemporal control over material behavior through multimodal photothermal stimuli.
• This work opens new avenues for designing sophisticated soft robots and biomedical devices with adaptive functionalities.