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Single-Molecule Analysis of MicroRNA and Logic Operations Using a Smart Plasmonic Nanobiosensor

Zhang, Ying, Shuai, Zhenhua, Zhou, Hao, Luo, Zhimin, Liu, Bing, Zhang, Yinan, Zhang, Lei, Chen, Shufen, Chao, Jie, Weng, Lixing, Fan, Quli, Fan, Chunhai, Huang, Wei, Wang, Lianhui
Journal of the American Chemical Society 2018 v.140 no.11 pp. 3988-3993
DNA, diagnostic techniques, environmental monitoring, genes, hybridization, microRNA, nanomaterials, surface plasmon resonance, wavelengths
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.