Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Biosensors (Basel). 2020 Jul 20;10(7):78. doi: 10.3390/bios10070078.
BRCA1 is the biomarker for the early diagnosis of breast cancer. Detection of BRCA1 has great significance for the genetic analysis, early diagnosis and clinical treatment of breast cancer. In this work, we developed a simple electrochemical DNA sensor based on a DNA tetrahedral-structured probe (TSP) and poly-adenine (polyA) mediated gold nanoparticles (AuNPs) for the sensitive detection of BRCA1. A thiol-modified TSP was used as the scaffold on the surface of the screen-printed AuNPs electrode. The capture DNA (TSP) and reporter DNA were hybridized to the target DNA (BRCA1), respectively, to form the typical sandwich system. The nanocomposites of reporter DNA (polyA at the 5' end) combined with AuNPs were employed for signal amplification which can capture multiple enzymes by the specificity between biotin and streptavidin. Measurements were completed in the electrochemical workstation by cyclic voltammetry and amperometry and we obtained the low limit of detection of 0.1 fM with the linear range from 1 fM to 1 nM. High sensitivity and good specificity of the proposed electrochemical DNA sensor showed potential applications in clinical early diagnosis for breast cancer.
BRCA1 是乳腺癌早期诊断的生物标志物。检测 BRCA1 对乳腺癌的遗传分析、早期诊断和临床治疗具有重要意义。在这项工作中，我们开发了一种基于 DNA 四面体型探针（TSP）和聚腺苷酸（polyA）介导的金纳米粒子（AuNPs）的简单电化学 DNA 传感器，用于灵敏检测 BRCA1。巯基修饰的 TSP 被用作丝网印刷 AuNPs 电极表面的支架。捕获 DNA（TSP）和报告 DNA 分别与靶 DNA（BRCA1）杂交，形成典型的三明治体系。与 AuNPs 结合的具有 5'端 polyA 的报告 DNA 的纳米复合材料用于信号放大，该信号放大可通过生物素和链霉亲和素之间的特异性捕获多个酶。通过循环伏安法和安培法在电化学工作站中完成测量，我们获得了低至 0.1 fM 的检测限，线性范围从 1 fM 到 1 nM。所提出的电化学 DNA 传感器具有高灵敏度和良好的特异性，显示出在乳腺癌临床早期诊断中的潜在应用。
