Department of Rehabilitation Medicine, the Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huaian, 223300, China.
Department of Chemistry, New York University, New York, NY, 10003, USA.
Mikrochim Acta. 2024 Mar 4;191(4):173. doi: 10.1007/s00604-024-06208-4.
MicroRNA detection is crucial for early infectious disease diagnosis and rapid cancer screening. However, conventional techniques like reverse transcription-quantitative polymerase chain reaction, requiring specialized training and intricate procedures, are less suitable for point-of-care analyses. To address this, we've developed a straightforward amplifier based on an exonuclease III (exo III)-propelled DNAzyme walker for sensitive and selective microRNA detection. This amplifier employs a specially designed hairpin probe with two exposed segments for strand recognition. Once the target microRNA is identified by the hairpin's extended single-strand DNA, exo III initiates its digestion, allowing microRNA regeneration and subsequent hairpin probe digestion cycles. This cyclical process produces a significant amount of DNAzyme, leading to a marked reduction in electrochemical signals. The biosensor exhibits a detection range from 10 fM to 100 pM and achieves a detection limit of 5 fM (3σ criterion). Importantly, by integrating an "And logic gate," our system gains the capacity for simultaneous diagnosis of multiple microRNAs, enhancing its applicability in RNA-based disease diagnostics.
微 RNA 检测对于早期传染病诊断和癌症的快速筛查至关重要。然而，传统技术如反转录-定量聚合酶链反应，需要专门的培训和复杂的程序，不太适合即时分析。为了解决这个问题，我们开发了一种基于外切酶 III（exo III）驱动的 DNA zyme walker 的简单放大器，用于灵敏和选择性的 microRNA 检测。该放大器采用一种特殊设计的发夹探针，具有两个暴露的片段用于链识别。一旦目标 microRNA 被发夹的延伸单链 DNA 识别，exo III 就会开始消化，允许 microRNA 再生和随后的发夹探针消化循环。这个循环过程会产生大量的 DNAzyme，导致电化学信号显著降低。该生物传感器的检测范围从 10 fM 到 100 pM，检测限为 5 fM（3σ 标准）。重要的是，通过集成“与逻辑门”，我们的系统能够同时诊断多种 microRNAs，提高了其在基于 RNA 的疾病诊断中的适用性。
