Mg2+- dependent six-jawed trap-mediated SERS biosensor for ratiometric detection of microRNA with use of the highly ordered Au NCs as substrate

作者：Shanyou Man, Xinli Zhang, Shixin Zhou, Jinzhuo Ran, Xia Yang, Ruo Yuan, Yaqin Chai · 发表于：Sensors and Actuators B Chemical · 年份：2024 · DOI：10.1016/j.snb.2024.136619 · 被引用次数：8 · 研究领域：Advanced biosensing and bioanalysis techniques、Advanced Nanomaterials in Catalysis、Gold and Silver Nanoparticles Synthesis and Applications

Herein, a ratiometric surface-enhanced Raman scattering (SERS) biosensor was constructed with use of the highly ordered gold nanocubes (Au NCs) interface created by the liquid-phase assembly as substrate, and a novel Mg 2+ -dependent six-Jawed trap (SJT) cyclical amplification strategy for sensitive detection of microRNA 221 (miRNA-221). Impressively, in contrast to conventional gold nanoparticles (Au NPs), Au NCs with more sharp corners and edge characteristics can significantly improve the Raman signals of the Raman molecules, while the highly ordered Au NCs prepared by liquid-phase assembly can also increase the stability and repeatability of miRNA-221 detection. In addition, the newly constructed SJT with more Mg 2+ shear sites were utilized to efficiently release plentiful output DNA with the Raman molecule methylene blue (MB) for greatly enhancing the sensitivity of the SERS biosensor . Ultrasensitive ratiometric SERS detection of miRNA-221 was realized by capturing the output DNA containing MB to generate ratiometric Raman signals at the sensing interface modified with Cyanine 5 (Cy5) Raman molecules. The SERS biosensor analyzed for miRNA-221 from 1 fM - 10 nM with an identification limit of 0.66 fM, and the approach is also effective for detecting miRNA-221 in cell lysates. Notably, the SJT signal amplification strategy utilized in this study makes it easier to create extremely sensitive biosensors and opens up new avenues for early detection of hepatocellular carcino...