摘要目的:构建一种太赫兹（THz）超材料传感方法用于microRNA-21（miRNA-21）的信号放大检测。方法:首先构建THz超材料传感方法，并用聚丙烯酰胺凝胶电泳及zeta电位验证方法的可行性；对传感器检测条件进行优化之后，对不同浓度的miRNA-21以及其他不同的miRNAs进行检测，并与其他microRNA检测方法进行比较；最后，对该传感器的回收率进行了评价。结果:在最优实验条件下，通过双链特异性核酸酶（DSN）循环识别与滚环扩增（RCA）的双重信号放大策略，该THz超材料传感器对靶标miRNA-21的响应范围为10 fmol/L至10 nmol/L，检测限为8.49 fmol/L。并且该传感器具有较好的特异性，具备了从多种miRNAs中识别靶标miRNA-21的能力，并且在商业化人血清样本中的回收率可达94.33%到115.33%。结论:该THz传感器可以实现靶标miRNA-21的高灵敏、高特异性检测，具备了在miRNA相关疾病无标记诊断与早期预警的潜力。

abstractsObjective:To construct of a terahertz metamaterial sensing method for detection of microRNA-21 (miRNA-21) based on duplex-specific nuclease triggered rolling circle amplification.Methods:First, a THz metamaterial sensing method was constructed, and verified by polyacrylamide gel electrophoresis and zeta potential; after optimizing the detection conditions of the sensor, different concentrations of miRNA-21 and other different miRNAs were detected. And this biosensor was compared with other miRNA detection methods; finally, the recovery rate of the biosensor was evaluated.Results:Under the optimal experimental conditions, through the dual signal amplification strategy of duplex-specific nuclease (DSN) cycle recognition and rolling circle amplification (RCA), the THz metamaterial sensor has a response range of 10 fmol/L to 10 nmol/L to the target miRNA-21, with a detection limit of 8.49 fmol/L. And the biosensor has good specificity with the ability to recognize the target miRNA-21 from a variety of microRNAs. And the experiment with recovery rate from 94.33% to 115.33% has been further verified in commercial human serum samples.Conclusion:The terahertz biosensor can achieve highly sensitive and specific detection of the target miRNA-21, which proves the potential for label-free diagnosis and early warning of miRNA-related diseases.