Analytical and Testing Center, Sichuan University , 29 Wangjiang Road, Chengdu, Sichuan 610064, China.
Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta , Edmonton, Alberta T6G 2G3, Canada.
Anal Chem. 2017 Dec 5;89(23):12888-12895. doi: 10.1021/acs.analchem.7b03529. Epub 2017 Nov 15.
We report here the concept of a self-powered, target-triggered DNA motor constructed by engineering a DNAzyme to adapt into binding-induced DNA assembly. An affinity ligand was attached to the DNAzyme motor via a DNA spacer, and a second affinity ligand was conjugated to the gold nanoparticle (AuNP) that was also decorated with hundreds of substrate strands serving as a high-density, three-dimensional track for the DNAzyme motor. Binding of a target molecule to the two ligands induced hybridization between the DNAzyme and its substrate on the AuNP, which are otherwise unable to spontaneously hybridize. The hybridization of DNAzyme with the substrate initiates the cleavage of the substrate and the autonomous movement of the DNAzyme along the AuNP. Each moving step restores the fluorescence of a dye molecule, enabling monitoring of the operation of the DNAzyme motor in real time. A simple addition or depletion of the cofactor Mg allows for fine control of the DNAzyme motor. The motor can translate a single binding event into cleavage of hundreds of substrates, enabling amplified detection of proteins at room temperature without the need for separation.
我们在这里报告了一种自供电、目标触发的 DNA 马达的概念，该马达通过工程化设计将 DNA 酶适配成结合诱导的 DNA 组装。亲和配体通过 DNA 间隔物连接到 DNA 酶马达上，而第二个亲和配体连接到金纳米粒子 (AuNP) 上，AuNP 还修饰有数百个底物链，作为 DNA 酶马达的高密度三维轨道。目标分子与两个配体的结合诱导 DNA 酶与其在 AuNP 上的底物之间的杂交，否则它们无法自发杂交。DNA 酶与底物的杂交启动了底物的切割和 DNA 酶沿着 AuNP 的自主运动。每个移动步骤恢复染料分子的荧光，从而能够实时监测 DNA 酶马达的运行。简单地添加或耗尽辅助因子 Mg 可以精细控制 DNA 酶马达。该马达可以将单个结合事件转化为数百个底物的切割，从而能够在室温下无需分离即可放大检测蛋白质。
