State Key Laboratory Base of Eco-chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
Biosens Bioelectron. 2010 Nov 15;26(3):1114-7. doi: 10.1016/j.bios.2010.08.018. Epub 2010 Aug 20.
A novel and ultrasensitive electrochemical approach for sequence-specific DNA detection based on signal dual-amplification with Au NPs and marker-loaded apoferritin NPs was reported. Target DNA was sandwiched between capture DNA coupled to magnetic beads and signal DNA self-assembled on Au NPs which were incorporated with marker-loaded apoferritin NPs. Subsequent electrochemical stripping analysis of the electroactive markers released from apoferritin NPs in acidic buffers provided a means to quantify the concentration of target DNA. In this means, one target signal could be transformed into multiple redox signals of the markers since a single Au NP could be loaded with dozens of apoferritin NPs, and an apoferritin NP could be loaded with thousands of markers. Under the optimum conditions, the linear range was from 2.0 × 10(-16) to 1.0 × 10(-14)M and the detection limit was 5.1 × 10(-17)M by using the cadmium as a model marker. The proposed DNA biosensor not only exhibited excellent sensitivity but also had good reproducibility and selectivity against two-base mismatched DNA.
报道了一种基于金纳米粒子和标记载入脱铁铁蛋白纳米粒子信号双重放大的新型超灵敏电化学方法，用于序列特异性 DNA 检测。目标 DNA 夹在与磁性珠偶联的捕获 DNA 和自组装在金纳米粒子上的信号 DNA 之间，金纳米粒子上载入了标记载入脱铁铁蛋白纳米粒子。随后，在酸性缓冲液中从脱铁铁蛋白纳米粒子中释放的电化学活性标记物的电化学剥离分析提供了一种定量目标 DNA 浓度的方法。在这种方法中，由于单个金纳米粒子可以负载数十个脱铁铁蛋白纳米粒子，并且一个脱铁铁蛋白纳米粒子可以负载数千个标记物，因此一个目标信号可以转化为多个标记物的氧化还原信号。在最佳条件下，使用镉作为模型标记物，线性范围为 2.0×10(-16)至 1.0×10(-14)M，检测限为 5.1×10(-17)M。所提出的 DNA 生物传感器不仅表现出优异的灵敏度，而且对两个碱基错配 DNA 具有良好的重现性和选择性。
