Song Weiling, Guo Xiaoyan, Sun Wenbo, Yin Wenshuo, He Peng, Yang Xiaoyan, Zhang Xiaoru
Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China.
Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, College of Chemical Science and Engineering, Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Shandong 266071, PR China.
Anal Biochem. 2018 Jul 15;553:57-61. doi: 10.1016/j.ab.2018.04.020. Epub 2018 Apr 24.
Detection of ultralow concentrations of nucleic acid sequences is a central challenge in the early diagnosis of genetic diseases. Herein, we developed a target-triggering cascade multiple cycle amplification for ultrasensitive DNA detection using quartz crystal microbalance (QCM) and surface plasmon resonance (SPR). It was based on the exonuclease Ⅲ (Exo Ⅲ)-assisted signal amplification and the hybridization chain reaction (HCR). The streptavidin-coated Au-NPs (Au-NPs-SA) were assembled on the HCR products as recognition element. Upon sensing of target DNA, the duplex DNA probe triggered the Exo Ⅲ cleavage process, accompanied by generating a new secondary target DNA and releasing target DNA. The released target DNA and the secondary target DNA were recycled. Simultaneously, numerous single strands were liberated and acted as the trigger of HCR to generate further signal amplification, resulting in the immobilization of abundant Au-NPs-SA on the gold substrate. The QCM sensor results were found to be comparable to that achieved using a SPR sensor platform. This method exhibited a high sensitivity toward target DNA with a detection limit of 0.70 fM. The high sensitivity and specificity make this method a great potential for detecting DNA with trace amounts in bioanalysis and clinical biomedicine.
检测超低浓度的核酸序列是遗传疾病早期诊断中的一项核心挑战。在此，我们开发了一种基于石英晶体微天平（QCM）和表面等离子体共振（SPR）的目标触发级联多循环扩增方法，用于超灵敏DNA检测。该方法基于核酸外切酶Ⅲ（Exo Ⅲ）辅助的信号放大和杂交链式反应（HCR）。将链霉亲和素包被的金纳米粒子（Au-NPs-SA）组装在HCR产物上作为识别元件。在检测到目标DNA时，双链DNA探针触发Exo Ⅲ切割过程，同时产生新的二级目标DNA并释放目标DNA。释放的目标DNA和二级目标DNA得以循环利用。同时，大量单链被释放出来并作为HCR的触发物，进一步产生信号放大，从而使大量Au-NPs-SA固定在金基底上。发现QCM传感器的结果与使用SPR传感器平台获得的结果相当。该方法对目标DNA表现出高灵敏度，检测限为0.70 fM。高灵敏度和特异性使得该方法在生物分析和临床生物医药中检测痕量DNA方面具有巨大潜力。
