Li Jing, Zhang Yansong, Wang Xin, Zhang Shenlong, Tan Qingqing, Hu Bingtao, Xu Qin, Li Hongbo
School of Chemistry and Chemical Engineering, Yancheng Institute of Technology, Yancheng 224051, P. R. China.
College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, P. R. China.
Anal Chem. 2023 Aug 15;95(32):12032-12038. doi: 10.1021/acs.analchem.3c01888. Epub 2023 Aug 5.
A DNA/RNA biosensor capable of single nucleotide variation (SNV) resolution is highly desirable for drug design and disease diagnosis. To meet the point-of-care demand, rapid, cost-effective, and accurate SNV detection is of great significance but still suffers from a challenge. In this work, a unique nonenzymatic dual-modal (multicolorimetric and photothermal) visualization DNA biosensor is first proposed for SNV identification on the basis of an entropy-driven nanomachine with double output DNAs and coordination etching of anisotropic silver triangular nanoplates (Ag TNPs). When the target initiates the DNA nanomachine, the liberated multiple output DNAs can be utilized as a bridge to produce a superparamagnetic sandwich complex. The incoming poly-C DNA can coordinate and etch highly active Ag ions at the tips of Ag TNPs, causing a shift in the plasmon peak of Ag TNPs from 808 to 613 nm. The more target DNAs are introduced, the more output DNAs are released and thus the more Ag ions are etched. The noticeable color changes of anisotropic Ag TNPs can be differentiated by "naked eye" and accurate temperature reading. The programmable DNA nanotechnology and magnetic extraction grant the high specificity. Also, the SNV detection results can be self-verified by the two-signal readouts. Moreover, the dual-modal biosensor has the advantages of portability, cost-effectiveness, and simplicity. Particularly, the exclusive entropy-driven amplifier liberates double output DNAs to bridge more poly-C DNAs, enabling the dual-modal visualization DNA biosensor with improved sensitivity.
一种能够实现单核苷酸变异（SNV）分辨的DNA/RNA生物传感器对于药物设计和疾病诊断非常有必要。为满足即时检测需求，快速、经济高效且准确的SNV检测具有重要意义，但仍面临挑战。在这项工作中，首次提出了一种独特的非酶双模态（多比色和光热）可视化DNA生物传感器，用于基于具有双输出DNA的熵驱动纳米机器和各向异性银三角纳米片（Ag TNPs）的配位蚀刻进行SNV识别。当靶标启动DNA纳米机器时，释放的多个输出DNA可作为桥梁产生超顺磁性夹心复合物。进入的聚C DNA可与Ag TNPs尖端的高活性银离子配位并蚀刻，导致Ag TNPs的等离子体峰从808 nm移至613 nm。引入的靶标DNA越多，释放的输出DNA就越多，因此蚀刻的银离子也就越多。各向异性Ag TNPs明显的颜色变化可用“肉眼”区分并进行精确的温度读数。可编程DNA纳米技术和磁提取赋予了高特异性。此外，SNV检测结果可通过双信号读数进行自我验证。而且，双模态生物传感器具有便携、经济高效和简单的优点。特别地，独特的熵驱动放大器释放双输出DNA以桥接更多聚C DNA，使双模态可视化DNA生物传感器具有更高的灵敏度。
