Key Laboratory of Functional Molecular Solid, Ministry of Education, Anhui Key Laboratory of Chemo/Biosensing, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, 241000, PR China.
Key Laboratory of Functional Molecular Solid, Ministry of Education, Anhui Key Laboratory of Chemo/Biosensing, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, 241000, PR China.
Biosens Bioelectron. 2023 Nov 15;240:115594. doi: 10.1016/j.bios.2023.115594. Epub 2023 Aug 11.
Enzyme-free hybridization chain reaction (HCR) technology is often used as a signal amplification tool for the detection of different targets. In this study, an ultrasensitive and label-free method for detecting miRNA-21 was developed using the nanopore ionic current rectification (ICR) technology coupled with HCR technology. The probe oligonucleotide (DNA1) was combined with the gold-coated nanopore through the Au-S bond to form a DNA1-functionalized gold-coated nanopore (DNA1-Au-coated nanopore). Since miRNA-21 is partially complementary to DNA1, it can be selectively recognized by DNA1-functionalized gold-coated nanopores. The target (miRNA-21) can induce the opening of hairpin DNA and HCR reaction after the introduction of hairpin DNA H1 and H2. The concentration of miRNA-21 will affect the combination of H1 and H2 on the inner wall of the nanopore, and its surface charge will change with the internal modification, thereby changing the ion current rectification ratio. Under the condition that the concentration of H1, H2 and HCR reaction time are constant, the change of ICR ratio is linearly correlated with the logarithm of miRNA-21 concentration within a certain range, which shows that the sensing strategy we designed can achieve target miRNA-21 detection. This ultrasensitive miRNA holds great promise in the field of cancer diagnosis.
无酶杂交链式反应 (HCR) 技术常被用作不同靶标检测的信号放大工具。本研究采用纳米孔离子电流整流 (ICR) 技术与 HCR 技术相结合，开发了一种用于检测 miRNA-21 的超灵敏、无标记方法。探针寡核苷酸 (DNA1) 通过 Au-S 键与金包被纳米孔结合，形成 DNA1 功能化的金包被纳米孔 (DNA1-Au-coated nanopore)。由于 miRNA-21 与 DNA1 部分互补，因此可以被 DNA1 功能化的金包被纳米孔选择性识别。靶标 (miRNA-21) 可以在引入发夹 DNA H1 和 H2 后诱导发夹 DNA 的打开和 HCR 反应。miRNA-21 的浓度会影响 H1 和 H2 在纳米孔内壁的结合，其表面电荷会随着内部修饰而变化，从而改变离子电流整流比。在 H1、H2 和 HCR 反应时间的浓度恒定的条件下，ICR 比值的变化与 miRNA-21 浓度的对数在一定范围内呈线性相关，表明我们设计的传感策略可以实现对靶标 miRNA-21 的检测。这种超灵敏的 miRNA 在癌症诊断领域具有广阔的应用前景。
