Smart and emerging DNA hydrogel-based sensing: From design to point-of-care testing

DNA hydrogels, three-dimensional networks with nucleic acid chains serving as fundamental structural units, have recently garnered significant attention in biomedicine and bioanalysis. Nevertheless, their translational potential in point-of-care testing (POCT) has not been fully elucidated from a perspective encompassing material design, response mechanisms, and device integration. The programmable matrix of DNA hydrogels efficiently anchors molecular recognition elements for target capture while spatially confining signal amplification to enhance sensitivity. Meanwhile, hydrogel transitions, like gel-sol transition, swelling or shrinking, directly translate biochemical inputs into observable outputs for stimulus response. This multifunctional integration configures DNA hydrogels into a biosensing-transduction platform, thereby facilitating combination with miniaturized POCT. In this review, we offer a novel perspective by focusing on engineered stimulus responsiveness of DNA hydrogels tailored for POCT. Firstly, the classification of pure and hybrid DNA hydrogels with synthetic approaches was outlined. Then, we detailed design strategies to achieve target-specific structural transition via CRISPR-guided site-specific linker cleavage, aptamer-conformational switching-mediated crosslink dissociation, and stimulus-triggered on-demand payload release. Furthermore, we systematically summarized compatible integration of responsive hydrogels with POCT platforms, including optical, liquid-level, handheld, microfluidic and wearable devices. Finally, key challenges and future prospects for advancing DNA hydrogels in the POCT field were discussed. This review is the first to provide a translational roadmap that bridges molecular design of responsive DNA hydrogels with practical POCT device requirements, offering unique guidance for advancing next-generation field-deployable diagnostics. • Focus on POCT Integration and Miniaturization We provide a POCT-oriented translational framework from material design to signal transduction, and to field-deployable platforms. It specifically focuses on the integration of DNA hydrogels with portable, miniaturized, and field-deployable POCT systems. • Emphasis on Stimulus-Responsive Mechanisms for Applications We dedicatedly analyze stimulus-responsive behaviors, especially target-induced gel-sol transition towards pH, enzyme, light, and CRISPR-triggered responses, and their translation into readable outputs such as colorimetric, fluorescence, distance and electrochemical strategies. This goes beyond the general overview of DNA hydrogel properties and delves into how these responses enable real-time, in-field diagnostics. • Translational Roadmap and Future-Oriented Perspective We include a critical discussion on scalability, stability, cost, and user-friendliness which are key factors for transitioning from lab to market. This roadmap integrates post-2020 breakthroughs such as CRISPR integration and wearable devices. • Structured for both Experts and Non-Specialist Readers The review is written in an accessible and authoritative style, making it suitable for a broad audience including material scientists, biomedical engineers, clinical researchers and non-expert readers.