National Engineering Laboratory for Fiber Optic Sensing Technology, Wuhan University of Technology, Wuhan, 430070, People's Republic of China.
Nanotechnology. 2020 Feb 21;31(9):095501. doi: 10.1088/1361-6528/ab55b7. Epub 2019 Nov 8.
For the early diagnosis of gastric cancer, microRNA-148a (miRNA-148a) as a promising biomarker is measured by a simple colorimetric biosensor due to its unique surface plasmon resonance (SPR) absorption of gold nanoparticles (AuNPs). In the assay system, the sensing probes are facilitated by the conjugation of AuNPs with RNA probes (RNA) via Au-S bonds, which align in a tail-to-tail fashion onto the target RNA. When miRNA-148a is introduced, a sandwich hybridization reaction is triggered between the AuNP-RNA conjugates and targets, resulting in changes in the SPR absorption band, microscopic distribution and macroscopic color of the AuNP solution. Following this principle, this colorimetric method is able to quantitatively detect miRNA-148a at nanomolar level with a limit of ∼1.9 nM, and exhibits high sensitivity and selectivity by a low-cost UV-vis spectrometer or even the naked eye. Moreover, the AuNP network materials with a characteristic sharp 'melting transition' provide significant guidance for the reusability of DNA or RNA biosensors.
为了实现胃癌的早期诊断，采用一种简单的比色生物传感器来测量微小 RNA-148a（miRNA-148a），这是一种很有前途的生物标志物，因为它具有金纳米粒子（AuNPs）独特的表面等离子体共振（SPR）吸收。在检测系统中，通过 Au-S 键将 AuNPs 与 RNA 探针（RNA）偶联，使传感探针能够与靶 RNA 以尾对尾的方式排列。当引入 miRNA-148a 时，AuNP-RNA 缀合物与靶标之间会引发夹心杂交反应，导致 SPR 吸收带、AuNP 溶液的微观分布和宏观颜色发生变化。基于这一原理，这种比色法能够以纳摩尔级的低限（约 1.9 nM）定量检测 miRNA-148a，并且通过低成本的紫外-可见分光光度计甚至肉眼即可实现高灵敏度和选择性。此外，AuNP 网络材料具有特征性的尖锐“熔融转变”，为 DNA 或 RNA 生物传感器的可重复使用提供了重要指导。
