Ultra high sensitive and simple detection of DNA is crucial to early diagnosis of diseases and biodefense application. Herein, we report an amplified chemiluminescence (CL) biosensing platform for ultralow concentration DNA detection. It is based on the distinguishing ability of positively charged gold nanoparticles ((+)AuNPs) between ss-DNA and ds-DNA. (+)AuNPs’ effect on luminol CL reaction is used to amplify the response signal of target DNA. Moreover, the three key experimental procedures (DNA hybridization, ss-DNA action on (+)AuNPs and CL detection) in the proposed strategy are independent so that the three experiments can occur in the own optimal condition, respectively. (+)AuNPs’ direct effect produced by different structure DNAs (ss-DNA and ds-DNA) can make CL signal to be significantly amplified. The proposed biosensing has high sensitivity for detecting target DNA. The detection limit of target DNA was 0.62 fM, which was lower than that of the reported DNA assays based on other signal amplification. Also, the present method is more convenient. Such direct signal amplification from nanometer interface effect will provide a promising alternative avenue for the construction of high sensitive CL sensing platform. It is especially noteworthy that the action mechanisms of AuNPs and DNA can be clarified by this research, which will be important theoretical support for the design of DNA biosensors.

DNA的超高灵敏度和简单检测对于疾病的早期诊断和生物防御应用至关重要。在本文中，我们报告了用于超低浓度DNA检测的放大的化学发光（CL）生物传感平台。它基于ss-DNA和ds-DNA之间带正电的金纳米颗粒（（+）AuNPs）的区分能力。（+）AuNPs对鲁米诺CL反应的作用被用于扩增靶DNA的响应信号。此外，所提出的策略中的三个关键实验步骤（DNA杂交，ss-DNA对（+）AuNPs的作用和CL检测）是独立的，因此这三个实验可以分别在自己的最佳条件下进行。（+）由不同结构的DNA（ss-DNA和ds-DNA）产生的AuNPs的直接作用可以使CL信号显着扩增。提出的生物传感技术对检测目标DNA具有很高的灵敏度。目标DNA的检出限为0.62 fM，低于报告的基于其他信号放大的DNA分析的检出限。而且，本方法更方便。这种来自纳米界面效应的直接信号放大将为高灵敏度CL感测平台的构建提供有希望的替代途径。特别值得一提的是，这项研究可以阐明AuNPs和DNA的作用机理，这将为DNA生物传感器的设计提供重要的理论支持。这种来自纳米界面效应的直接信号放大将为高灵敏度CL感测平台的构建提供有希望的替代途径。特别值得一提的是，这项研究可以阐明AuNPs和DNA的作用机理，这将为DNA生物传感器的设计提供重要的理论支持。这种来自纳米界面效应的直接信号放大将为高灵敏度CL感测平台的构建提供有希望的替代途径。特别值得一提的是，这项研究可以阐明AuNPs和DNA的作用机理，这将为DNA生物传感器的设计提供重要的理论支持。