Dual-Signal Mode Ratiometric Photoelectrochemical Sensor Based on G-Quadruplex Hole Transport for Rapid and Sensitive Detection of miRNA-210

作者：Jing Li, Cheng Chen, Fang Luo, Cuiying Lin, Zhenyu Lin, Jian Wang, Bin Qiu · 发表于：Analytical Chemistry · 年份：2023 · DOI：10.1021/acs.analchem.3c03447 · 被引用次数：27 · 研究领域：Advanced biosensing and bioanalysis techniques、RNA Interference and Gene Delivery、DNA and Nucleic Acid Chemistry

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 2+ 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 ( R 2 = 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.