State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, PR China.
Anal Chem. 2012 Oct 16;84(20):8602-6. doi: 10.1021/ac3016196. Epub 2012 Oct 1.
We have developed a novel concept for enzymatic control of plasmonic coupling as a surface enhanced Raman scattering (SERS) nanosensor for DNA demethylation. This nanosensor is constructed by decorating gold nanoparticles (AuNPs) with Raman reporters and hemimethylated DNA probes. Demethylation of DNA probes initiates a degradation reaction of the probes by methylation-sensitive endonuclease Bsh 1236I and single-strand selective exonuclease I. This destabilizes AuNPs and mediates the aggregation of AuNPs, generating a strong plasmonic coupling SERS signal in response to DNA demethylation. This nanosensor has the advantages in its high signal-to-noise ratio, superb specificity, and rapid, convenient, and reproducible detection with homogeneous, single-step operation. Thus, it provides a useful platform for detecting DNA demethylation and related molecular diagnostics and drug screening. This work is the first time that enzymatic degradation of DNA substrate probes has been utilized to induce aggregation of AuNPs such that reproducible, sensitive SERS signals can be achieved from biological recognition events. This enzymatic control mechanism for plasmonic coupling may create a new paradigm for the development of SERS nanosensors.
我们提出了一种新颖的概念，通过酶促控制等离子体耦合，将其作为一种表面增强拉曼散射（SERS）纳米传感器，用于 DNA 去甲基化检测。该纳米传感器通过将拉曼报告分子和半甲基化 DNA 探针修饰到金纳米颗粒（AuNPs）上来构建。DNA 探针的去甲基化会引发甲基化敏感内切酶 Bsh 1236I 和单链选择性核酸外切酶 I 对探针的降解反应。这会使 AuNPs 失稳，并介导 AuNPs 的聚集，从而在响应 DNA 去甲基化时产生强烈的等离子体耦合 SERS 信号。该纳米传感器具有高信噪比、超特异性以及快速、方便、可重现的优点，采用均相、单步操作。因此，它为检测 DNA 去甲基化及相关分子诊断和药物筛选提供了一个有用的平台。这项工作首次利用酶促降解 DNA 底物探针来诱导 AuNPs 的聚集，从而可以从生物识别事件中获得可重复、灵敏的 SERS 信号。这种等离子体耦合的酶控机制可能为 SERS 纳米传感器的发展开创一个新的范例。
