Electrical detection of RNAs using transistor-based biosensors has attracted attention as a strategy for medical diagnosis and environmental monitoring. Herein, we demonstrated a proof-of-concept for specific, sensitive, and label-free RNA detection using a field-effect transistor (FET) biosensor with signal amplification by ternary initiation complexes (SATIC), which is an isothermal one-step nucleic acid amplification initiated by the combination of target RNA, circular DNA template and DNA primer. The SATIC system-applied FET biosensor specifically and quantitatively detected the target RNA with a single-nucleotide difference via the negative charges derived from the amplification products formed by a nucleic acid amplification reaction with φ29 DNA polymerase on the gate surface. In particular, the control of the amplification time allowed the detection of target RNA molecules over a wide concentration range, resulting in a detection limit of up to 6 copies/μL. Therefore, a transistor-based bioassay using the SATIC system could be useful for simple and sensitive nucleic acid analysis.

中文翻译：

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场效应晶体管生物传感器，通过三元引发复合物放大信号，用于检测宽范围 RNA 浓度

使用基于晶体管的生物传感器对 RNA 进行电检测作为医学诊断和环境监测的策略已引起人们的关注。在此，我们展示了使用场效应晶体管 (FET) 生物传感器进行特异性、灵敏和无标记 RNA 检测的概念验证，并通过三元起始复合物 (SATIC) 进行信号放大，这是一种等温一步核酸由靶RNA、环状DNA模板和DNA引物的组合引发的酸扩增。 SATIC系统应用的FET生物传感器通过门表面的φ29 DNA聚合酶与核酸扩增反应形成的扩增产物所产生的负电荷，特异性地定量检测具有单核苷酸差异的目标RNA。特别是，扩增时间的控制允许在较宽的浓度范围内检测靶RNA分子，导致检测限高达6拷贝/μL。因此，使用 SATIC 系统的基于晶体管的生物测定可用于简单且灵敏的核酸分析。