Programmable DNA hydrogels construction with functional regulations for biosensing applications

DNA hydrogels are hydrophilic polymer networks formed by DNA cross-linked polymer backbones or self-assembly of DNA building blocks. Following Watson-Crick base pairing principle and switchable recognition capability towards a wide range of biomolecules, programmable DNA assembly or disassociation events can be applied for the fabrication of highly sensitive biosensors. DNA hydrogels have excellent biocompatibility, degradability, stability and mechanical properties, which have attracted extensive attention. Recently, various functional DNA hydrogels have emerged with the development of nucleic acids amplification strategies and the incorporation of suitable nanomaterials. In this review, we first provide a comprehensive overview of the synthesis principles of DNA hydrogels. The functional regulations are highlighted. Recent advances on the development of DNA hydrogels-based biosensors are then discussed with selected examples. In the final section, challenges and perspectives for the biosensing applications are prospected.