Key Laboratory for Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Jiangsu National Synergistic Innovation Center for Advanced Materials (SICAM), College of Electronic and Optical Engineering & College of Microelectronic , Nanjing University of Posts & Telecommunications , 9 Wenyuan Road , Nanjing 210023 , China.
Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics , Chinese Academy of Sciences , Shanghai 201800 , China.
J Am Chem Soc. 2018 Mar 21;140(11):3988-3993. doi: 10.1021/jacs.7b12772. Epub 2018 Mar 9.
Analysis of biomolecules at the single-molecule level is a great challenge in molecular diagnostics, gene profiling, and environmental monitoring. In this work, we design a smart plasmonic nanobiosensor based on individual Au@Ag core-shell nanocube (Au@Ag NC) modified with tetrahedron-structured DNA (tsDNA) for detecting microRNA 21 (miR-21) at the single-molecule level. An average localized surface plasmon resonance (LSPR) scattering spectral wavelength shift of approximately 0.4 nm can be obtained for a single miR-21 hybridization event on the nanobiosensor. In addition, the sensing mechanism of the individual Au@Ag NC is further verified by the three-dimensional finite-difference time-domain (3D-FDTD) simulations. Notably, this system not only allows the real-time detection of miR-21 with an aM level sensitivity over a large dynamic range from 1 aM to 1 nM, but also enables DNA-based logic operations as well as biomemory by exploiting miR-21, KpnI, and StuI-responsive assays. Our study opens a unique method for single-molecule detection of biomolecules and thus holds great promise in a variety of biological and biomedical applications.
在分子诊断学、基因分析和环境监测领域，对生物分子进行单分子水平分析是一个巨大的挑战。在这项工作中，我们设计了一种基于单个 Au@Ag 核壳纳米立方（Au@Ag NC）的智能等离子体纳米生物传感器，该纳米生物传感器用四面体结构 DNA（tsDNA）进行修饰，可用于单分子水平检测 microRNA 21（miR-21）。在纳米生物传感器上进行单个 miR-21 杂交事件，可获得约 0.4nm 的平均局域表面等离子体共振（LSPR）散射光谱波长位移。此外，还通过三维有限差分时域（3D-FDTD）模拟进一步验证了单个 Au@Ag NC 的传感机制。值得注意的是，该系统不仅可以实时检测具有 aM 级灵敏度的 miR-21，检测范围从 1 aM 到 1 nM 很宽，而且还可以通过利用 miR-21、KpnI 和 StuI 反应性测定来进行基于 DNA 的逻辑运算和生物存储。我们的研究为生物分子的单分子检测开辟了一种独特的方法，因此在各种生物和生物医学应用中具有广阔的应用前景。
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