Liu Yan, Liu Ziqi, Yan Tingxiu, Feng Luyao, He Na, Tao Lu, Xu Li-Ping, Zhang Xueji
Research Center for Bioengineering and Sensing Technology, Beijing Key Laboratory for Bioengineering and Sensing Technology, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, P.R. China.
Analyst. 2025 Jan 13;150(2):362-370. doi: 10.1039/d4an01065e.
Acute myocardial infarction (AMI) accounts for a significant proportion of global fatalities, and early detection is crucial for improving patient outcomes. However, current diagnostic methods often struggle to detect AMI in its early stages. Herein, we present an electrochemical sensor utilizing a fractal gold (FracAu) electrode and hybridization chain reaction (HCR) amplification technology to detect AMI-specific microRNAs (miRNAs). When the target sequence was added, the HCR was triggered, leading to the formation of a long-nicked DNA double helix that efficiently captured a larger quantity of positively charged RuHex molecules, resulting in significant electrochemical signal amplification. More importantly, to avoid false positive signals, exonuclease I (Exo I) was introduced to selectively cleave single-stranded DNA (ssDNA) probes. These ssDNA probes, underwent random hydrolysis from hpDNA probes, could hybridize with helper DNA1 in the absence of the target, initiating the HCR process and producing a false positive signal. The inclusion of Exo I effectively avoided false positive signals and reduced background noise. Under optimized conditions, the fabricated sensor exhibited significant sensitivity and selectivity, showing a broad linear detection range from 10 pM to 10 nM and a low limit of 0.9 fM. The fabricated electrochemical sensor also successfully detected AMI-specific miRNA in real serum samples, underscoring its diagnostic promise. By providing a reliable tool for early detection, the innovative sensor holds significant potential in combating global cardiovascular disease-related mortality rates.
急性心肌梗死（AMI）在全球死亡病例中占很大比例，早期检测对于改善患者预后至关重要。然而，目前的诊断方法在AMI早期检测方面往往存在困难。在此，我们展示了一种利用分形金（FracAu）电极和杂交链式反应（HCR）扩增技术来检测AMI特异性微小RNA（miRNA）的电化学传感器。当加入靶序列时，HCR被触发，导致形成长切口的DNA双螺旋，该双螺旋有效地捕获了大量带正电荷的RuHex分子，从而实现显著的电化学信号放大。更重要的是，为避免假阳性信号，引入了核酸外切酶I（Exo I）以选择性切割单链DNA（ssDNA）探针。这些从发夹DNA探针随机水解而来的ssDNA探针，在没有靶标的情况下可与辅助DNA1杂交，启动HCR过程并产生假阳性信号。Exo I的加入有效避免了假阳性信号并降低了背景噪声。在优化条件下，所制备的传感器表现出显著的灵敏度和选择性，线性检测范围宽，从10 pM到10 nM，检测下限低至0.9 fM。所制备的电化学传感器还成功检测了实际血清样本中的AMI特异性miRNA，凸显了其诊断前景。通过提供一种可靠的早期检测工具，这种创新型传感器在降低全球心血管疾病相关死亡率方面具有巨大潜力。
