College of Chemistry and Chemical Engineering, Central South University , Changsha, China , 410083.
National Cancer Institute, National Institutes of Health , Rockville, Maryland 20850, United States.
Anal Chem. 2017 Oct 3;89(19):10264-10269. doi: 10.1021/acs.analchem.7b01747. Epub 2017 Sep 13.
We have developed a new DNA self-assembly amplification technology that generates electric current for electrochemical biosensing. The new technology was used for detection of human epidermal growth factor receptor 2 (HER2). In our technology, an aptamer was utilized both as a ligand for recognition and as a signal generating reporter. The aptasensor is based on a sandwich format and a DNA primer on a HER2 aptamer initiates auxiliary DNA self-assembled on the electrode to form a long one-dimensional DNA. The resulting DNA is then reacted with molybdate to generate electrochemical current. The sensitivity of the aptasensor with DNA self-assembly was greater than that of the aptasensor without DNA self-assembly due to the extended length of the DNA strand. Aptasensor analysis of HER2 in serum of breast cancer patients and healthy individuals is highly correlated (R = 0.9924) with ELISA measurements, with a p value of 1.37 × 10. The analysis of HER2 in serum (confirmed by ELISA) suggests that HER2 levels in breast cancer patients are much higher than healthy individuals. For HER2 positive patients, the levels are higher than those of HER2 negative patients. After surgery, there is a drop of HER2 levels in serum, suggesting potential clinical applications of the new self-assembled DNA electric current generating biosensor. Unlike proteins, DNA is easily amplifiable. The DNA signal amplification method presented here enables effective current generation, which can find wide range of biomedical applications for protein detection.
我们开发了一种新的 DNA 自组装扩增技术，可产生用于电化学生物传感的电流。该新技术用于检测人表皮生长因子受体 2（HER2）。在我们的技术中，适体既用作配体识别，又用作信号产生报告器。适体传感器基于三明治结构，HER2 适体上的 DNA 引物启动辅助 DNA 在电极上自组装，形成长的一维 DNA。所得 DNA 然后与钼酸盐反应以产生电化学电流。由于 DNA 链的延长，具有 DNA 自组装的适体传感器的灵敏度大于没有 DNA 自组装的适体传感器的灵敏度。适体传感器对乳腺癌患者和健康个体血清中 HER2 的分析与 ELISA 测量高度相关（R = 0.9924），p 值为 1.37×10。对血清中 HER2 的分析（通过 ELISA 证实）表明，乳腺癌患者的 HER2 水平明显高于健康个体。对于 HER2 阳性患者，水平高于 HER2 阴性患者。手术后，血清中的 HER2 水平下降，表明新的自组装 DNA 电流产生生物传感器具有潜在的临床应用。与蛋白质不同，DNA 易于扩增。本文提出的 DNA 信号放大方法可实现有效的电流产生，可广泛应用于蛋白质检测的生物医学应用。
