Programmable DNA hydrogels for biosensing and point-of-care test

The double-helix polymer deoxyribonucleic acid (DNA) demonstrates specificity and programmability via complementary base pairing, making it a biometric component for target recognition. Meanwhile, hydrogel as a three-dimensional polymer can effectively isolate interfering substances in complex sample matrices, with the distinctive stimulus–response and gel-sol properties bolster their efficacy in biosensing applications. Therefore, the combination of DNA and hydrogel attributes renders DNA hydrogels a superior option in biosensing and point-of-care test (POCT). To prove the biosensing benefits of DNA hydrogels, this review provides a comprehensive overview of recent advancements in DNA hydrogels, focusing on their preparation, biosensing, and application. The common preparation methods of DNA hydrogels were introduced first, followed by a comprehensive summary of signal amplification strategies in biosensing and the application of DNA hydrogel-based biosensors. Furthermore, the limitations of DNA hydrogels in biosensing and POCT as well as future developments were also discussed. This review aims to stimulate interest regarding DNA hydrogels, with the hope that it can address the challenges encountered in the practical use of biosensing and POCT.