Li Hongbo, Han Min, Weng Xuan, Zhang Yuye, Li Jing
School of Chemistry and Chemical Engineering, Yancheng Institute of Technology, Yancheng 224051, PR China.
ACS Nano. 2021 Jan 26;15(1):1710-1717. doi: 10.1021/acsnano.0c09374. Epub 2021 Jan 13.
In virtue of the inherent molecular recognition and programmability, DNA has recently become the most promising for high-performance biosensors. The rationally engineered nucleic acid architecture will be very advantageous to hybridization efficiency, specificity, and sensitivity. Herein, a robust and split-mode photoelectrochemical (PEC) biosensor for miRNA-196a was developed based on an entropy-driven tetrahedral DNA (EDTD) amplifier coupled with superparamagnetic nanostructures. The DNA tetrahedron structure features in rigidity and structural stability that contribute to obtain precise identification units and specific orientations, improving the hybridization efficiency, sensitivity, and selectivity of the as-designed PEC biosensor. Further, superparamagnetic FeO@SiO@CdS particles integrated with DNA nanostructures are beneficial for the construction of a split-mode, highly selective, and reliable PEC biosensor. Particularly, the enzyme- and hairpin-free EDTD amplifier eliminates unnecessary interference from the complex secondary structure of pseudoknots or kissing loops in typical hairpin DNAs, significantly lowers the background noise, and improves the detection sensitivity. This PEC biosensor is capable of monitoring miRNA-196a in practical settings with additional advantages of efficient electrode fabrication, stability, and reproducibility. This strategy can be extended to various miRNA assays in complex biological systems with excellent performance.
凭借其固有的分子识别和可编程性，DNA最近已成为用于高性能生物传感器的最具潜力的材料。经过合理设计的核酸结构对杂交效率、特异性和灵敏度非常有利。在此，基于熵驱动的四面体DNA（EDTD）放大器与超顺磁性纳米结构相结合，开发了一种用于miRNA-196a的强大的分裂模式光电化学（PEC）生物传感器。DNA四面体结构具有刚性和结构稳定性，有助于获得精确的识别单元和特定方向，提高了所设计的PEC生物传感器的杂交效率、灵敏度和选择性。此外，与DNA纳米结构集成的超顺磁性FeO@SiO@CdS颗粒有利于构建分裂模式、高选择性和可靠的PEC生物传感器。特别地，无酶和发夹的EDTD放大器消除了典型发夹DNA中假结或吻环复杂二级结构产生的不必要干扰，显著降低了背景噪声，并提高了检测灵敏度。这种PEC生物传感器能够在实际环境中监测miRNA-196a，还具有高效电极制备、稳定性和可重复性等额外优势。该策略可以扩展到复杂生物系统中的各种miRNA检测，具有优异的性能。
