DETERMINATION OF DNA AND THROMBIN BY AN ELECTROCHEMICAL SENSOR EMPLOYING AGGREGATION OF CROSSLINKED GOLD NANOPARTICLES AND APTAMER SEGMENTS
DETERMINATION OF DNA AND THROMBIN BY AN ELECTROCHEMICAL SENSOR EMPLOYING AGGREGATION OF CROSSLINKED GOLD NANOPARTICLES AND APTAMER SEGMENTS
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DOI：
10.1080/00032719.2013.832271
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发表时间：
2014-01-22
影响因子：
2
通讯作者：
Fang, Yuzhi
中科院分区：
文献类型：
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作者：
Chang, Zhu;Zang, Yunbo;Fang, Yuzhi
在这项研究中，一种新的和超灵敏的生物传感器策略的基础上，金纳米粒子和适配体片段的设计，以检测两个生物分子的目标：DNA和凝血酶。设计了两种DNA探针，包括适体片段和核酸。在凝血酶存在下，适体片段组装成G-四链体结构，核酸与靶DNA形成双螺旋结构。两种金纳米粒子标记的DNA探针通过对靶分子的特异性识别而有效聚集。亚甲基蓝，单链DNA的氧化还原活性指示剂，被掺入到金纳米颗粒聚集体上的探针的未识别片段中。此外，金纳米粒子的聚集不仅为亚甲基蓝提供了良好的导电基体，而且丰富了亚甲基蓝分子。使用这种方法，DNA和凝血酶检测在低浓度范围内与两种探针。这些金纳米粒子聚集为基础的电极，其特征在于独立使用循环伏安法，电化学阻抗测量，和扫描电子显微镜。峰电流与DNA浓度在2.0 ~ 2.0pM范围内呈线性关系，与凝血酶浓度在2.0 ~ 2.0nM范围内呈线性关系。
In this study, a novel and ultrasensitive biosensor strategy based on gold nanoparticles and aptamer segments was designed to detect two biomolecule targets: DNA and thrombin. Two DNA probes were designed that included aptamer segments and nucleic acids. The aptamer segments assembled into a G-quadruplex structure in the presence of thrombin, and the nucleic acids formed a double helix structure with the target DNA. The two gold nanoparticle-labeled DNA probes were effectively aggregated by specific recognition of the target molecules. Methylene blue, a redox-active indicator of single-stranded DNA, was incorporated in the unrecognized segment of the probe on the gold nanoparticle aggregation. Furthermore, the gold nanoparticle aggregation not only provided an excellent conductive matrix for methylene blue, but also abundantly enriched the methylene blue molecule. Using this method, DNA and thrombin were detected in low concentration ranges with both probes. These gold nanoparticle aggregation-based electrodes were independently characterized using cyclic voltammetry, electrochemical impedance measurements, and scanning electron microscopy. The peak currents had a linear relationship with DNA concentration from 2.0fM to 2.0pM and with thrombin concentration from 2.0pM to 2.0nM.