One-step strand displacement-mediated nucleic acids signal-amplified analytical strategy based on superparamagnetism-functionalized DNA arrays.

DNA nanostructure, as polymeric material with remarkable molecular recognition property, has been widely used in bioassay. However, it still faces some challenges to overcome complexity of signal-amplified strategies and to realize efficient separation of reaction products. Herein, we present an innovative signal-amplified approach by integrating the toehold-mediated strand displacement reaction with DNA tile self-assembly technology to construct superparamagnetism-functionalized DNA polymeric materials, establishing a new signal-amplified analytical strategy for nucleic acids. This strategy enables highly sensitive, rapid, and efficient nucleic acid detection, making it a promising candidate for point-of-care testing (POCT). The analytical performance of this strategy was validated using target DNA (tDNA) and PIWI-interacting RNA-36026 (piRNA-36026), achieving limits of detection (LOD) of 2.4 × 10 M and 2.7 × 10 M. Moreover, it successfully detected single-base mutations and demonstrated stability over seven days. Comparative experiments confirmed the superior signal-amplified efficiency of DNA arrays. Recovery experiments yielded recoveries of 88.53 %-101.89 % for tDNA and 87.58 %-108.61 % for piRNA-36026. Ultimately, the feasibility of this strategy for real-world applications was validated through detecting piRNA-36026 in cell lysates. In conclusion, this work introduces an innovative and efficient signal-amplified method, while expanding the application prospects of multifunctional DNA polymeric materials in biomedical diagnostics.