基于三维DNA分子机器信号放大比率型拉曼光谱检测细胞内miRNA

A Ratiometric SERS Biosensor for miRNA Detection Based on Three-dimensional DNA Molecular Machine

构建了比率型-拉曼光谱3DDNA Walker纳米分子放大机器对肿瘤细胞标志物miRNA-21及肿瘤细胞进行检测。由miRNA-21作为3DDNA Walker的激活剂,其运动轨迹依赖于金纳米粒子的DNA高负载。3DDNA Walker触发后,由于DNA的循环信号放大作用,实现对miRNA-21的比率型拉曼光谱检测。比率型分析方法解决了分析条件的时空变化引起的信号波动,具有更高的灵敏度和可信度,此方法还可应用到肿瘤细胞的成像研究。

A ratiometric SERS nanosensing platform was fabricated for detection of miRNA coupling with a DNA tetrahedron-assisted 3D DNA Walker.The proposed nanomachine is actuated by target miRNA binding to blocker DNA.The autonomous and progressive walk on the DNA track via the intramolecular toehold-mediated strand displacement amplification.This method not only effectively avoided the false positive signal,but also proposed a new ratiometric method.The novel ratiometric strategy exhibited excellent specificity and sensitivity.Moreover,the nanomachine was applied for miRNA imaging inside living cells.