Biomimetic 3D DNA Nanomachine via Free DNA Walker Movement on Lipid Bilayers Supported by Hard SiO 2 @CdTe Nanoparticles for Ultrasensitive MicroRNA Detection

作者：Xin Peng, Zhi-Bin Wen, Peng Yang, Yaqin Chai, Wenbin Liang, Ruo Yuan · 发表于：Analytical Chemistry · 年份：2019 · DOI：10.1021/acs.analchem.9b03263 · 被引用次数：50 · 研究领域：Advanced biosensing and bioanalysis techniques、RNA Interference and Gene Delivery、Nanopore and Nanochannel Transport Studies

Herein, a novel three-dimensional (3D) DNA nanomachine with high walking efficiency via free DNA walker movement on biomimetic lipid bilayers supported by hard [email protected] quantum dots (SiO 2 @CdTe) was constructed for ultrasensitive fluorescence detection of microRNA. The synthesized SiO 2 @CdTe nanoparticles were adopted as the fluorescence indicator and spherical carrier of lipid bilayers, and then the DNA substrates were anchored on lipid bilayers with biomimetic fluidity through the cholesterol-lipid interaction. Once target microRNA-141 interacted with the 3D DNA nanomachine to release cholesterol labeled arm (Chol-arm), the Chol-arm could generate a series of strand displacement reactions by moving freely on the lipid bilayers, resulting in the releasement of numerous quenchers from the SiO 2 @CdTe nanoparticles and inducing a strong fluorescence signal. Impressively, compared with traditional 3D DNA nanomachine conjugating DNA substrates on hard surfaces (such as gold or silica) with limited reactivity, the proposed biomimetic 3D DNA nanomachine not only immobilized DNA substrates rapidly and effectively but also kept it with a favorable fluidity, which significantly enhanced the walking efficiency. As expected, the biomimetic 3D DNA nanomachine for fluorescence detection of microRNA-141 exhibited an excellent performance with a detection limit of 0.21 pM and presented promising properties in cell lysate detection and intracellular imaging. Thus, the described b...