One-Component DNA Mechanoprobes for Facile Mechanosensing in Photopolymerized Hydrogels and Elastomers

DNA mechanosensors offer unique properties for mechano-adaptive and self-reporting materials, such as programmable bond strength and geometrical strain response, tunable fluorescent strain sensing, interfacing to biological systems, and the ability to store mechanical information. However, the facile incorporation of advanced DNA motifs into polymer networks and achieving robustness in application settings remain difficult. Herein, we introduce one-component DNA mechanoprobes that can be easily polymerized into polymer hydrogels and even elastomers to allow strain-induced fluorescence sensing. The all-in-one mechanoprobe contains a DNA hairpin for programmable force sensing, an internal fluorophore-quencher pair as a reporter, and methacrylamide groups on both ends for rapid and facile photopolymerization into networks based on the nontoxic water-soluble monomer methoxy triethylene glycol acrylate (mTEGA). In addition to mechanosensing hydrogels, we utilize the low Tg of p(mTEGA) to develop the first bulk elastomer materials with DNA force sensors, which show high elasticity and stronger mechanofluorescence. The system makes decisive steps forward for DNA-based mechanoprobes by overcoming the classical multicomponent design of such probes, allowing photopolymerization useful for the design of complex objects or even 3D printing and demonstrating that such motifs may even be useful in dry bulk materials.