DNA-Based Functionalization of Hydrogels for Enhanced Properties

Abstract

Hydrogels can be tuned to induce volumetric changes in response to specific stimuli depending on their functionalization. Due to these tunable characteristics, they are widely utilized in various fields requiring high programmability, such as soft robotics and molecular sensing. However, current hydrogels encounter limitations where achieving complex structures or performing sophisticated tasks through conventional chemical functionalization necessitates additional processing steps. To overcome these constraints, we propose a strategy to functionalize the 3D network of hydrogels using DNA as a programmable tool, thereby significantly expanding the operational versatility of the material. Hydrogels achieving high programmability through this DNA-based approach can be implemented as either hydrogel actuators or single-molecule detection sensors. As actuators, these materials can transform into diverse structures on demand based on reprogrammable features. By integrating photo-reactive DNA cross-links, we overcome the limitations of traditional soft robotic hydrogel actuators, which are capable of only restricted transformations predetermined at the fabrication stage. These DNA cross-links act as regulators that allow for precise, reversible, and dynamic actuation through a one-pot reaction under patterned light. Simultaneously, DNA-functionalized hydrogels enable diagnostics at the single-molecule level by designing the network to react with target molecules through intrinsic DNA reaction mechanisms. This platform offers a high degree of freedom without the constraints of conventional diagnostic tools, such as the requirements for target amplification or specific thermal cycling. Ultimately, enhancing hydrogel properties through DNA-based functionalization serves as a novel solution for applications that require complex processes and high programmability.