Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou 350116, Fujian, China.
College of Biological Science and Engineering, Fuzhou University, Fuzhou 350116, Fujian, China.
Anal Chem. 2023 Dec 5;95(48):17670-17678. doi: 10.1021/acs.analchem.3c03447. Epub 2023 Nov 22.
For rapid and sensitive detection of miRNA-210, which is important for improving the reliability of clinical diagnosis of breast cancer, a dual-signal mode ratiometric photoelectrochemical (PEC) sensor based on a Au/GaN photoanode is proposed. First, a DNA probe was designed that could complement the target miRNA-210. Then, another G-rich DNA sequence was designed to mismatch the probe and form a double-stranded DNA (dsDNA). Upon addition of the target, the dsDNA unwinds from its binding site and releases G-rich single-stranded DNA. In the presence of Mg and K, this single-stranded DNA molecule spontaneously forms a G-quadruplex structure, facilitating the rapid transport of photogenerated holes, thereby increasing the photocurrent response of Au/GaN and enabling sensitive label-free detection of miRNA-210. By control of different pH values, a response signal was generated at pH 8, while a reference signal was produced at pH 5. The designed PEC system shows a high potential for the development of miRNA-210 detection. Ultimately, the response signal-to-reference signal ratio was used as the variable, and a broad linear span ranging from 10 fM to 1 nM ( = 0.993) has been exhibited, with a detection threshold of 3 fM (S/N = 3). The designed PEC platform shows potential for the development of other disease markers.
为了快速灵敏地检测 miRNA-210，这对于提高乳腺癌临床诊断的可靠性非常重要，提出了一种基于 Au/GaN 光电阳极的双信号模式比率型光电流化学（PEC）传感器。首先，设计了一种可以互补靶 miRNA-210 的 DNA 探针。然后，设计了另一个富含 G 的 DNA 序列来与探针不匹配并形成双链 DNA（dsDNA）。加入靶标后，dsDNA 从其结合位点解开并释放富含 G 的单链 DNA。在 Mg 和 K 的存在下，这种单链 DNA 分子自发形成 G-四链体结构，促进光生空穴的快速传输，从而提高 Au/GaN 的光电流响应，并实现对 miRNA-210 的敏感无标记检测。通过控制不同的 pH 值，在 pH 8 时产生响应信号，而在 pH 5 时产生参考信号。所设计的 PEC 系统显示出用于 miRNA-210 检测的巨大潜力。最终，将响应信号与参考信号的比值用作变量，展示了从 10 fM 到 1 nM（ = 0.993）的宽线性跨度，检测阈值为 3 fM（S/N = 3）。所设计的 PEC 平台显示出用于开发其他疾病标志物的潜力。
