Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, People's Republic of China.
Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, People's Republic of China.
Biosens Bioelectron. 2018 Mar 15;101:213-218. doi: 10.1016/j.bios.2017.10.032. Epub 2017 Oct 17.
We developed a novel "signal-off" photoelectrochemical (PEC) aptasensor based on an aptamer bridged DNA network structure for the sensitive detection of vascular endothelial growth factor (VEGF), using g-CN as photoactive material. The DNA network provides an excellent platform for the immobilization of methylene blue (MB), which can facilitate the electron transport through the DNA helix structure and suppress the recombination of electron-hole pairs generated by g-CN. In the presence of the target VEGF, the DNA network can be destroyed adequately by the recognition between VEGF and the aptamer, resulting in the release of MB. Therefore, the originally enhanced electron transfer process could be inhibited, leading to a remarkable decrease of the photocurrent. A good linear relationship between the PEC signal and the logarithm of VEGF concentration over the range of 100fM to 10nM with a detection limit of 30 fM can be obtained. Our concept can be easily extended to develop aptasensors for the sensitive detection of different targets by triggering the release of the payloads from their corresponding aptamer bridged DNA networks.
我们开发了一种基于适体桥连 DNA 网络结构的新型“信号关闭”光电化学 (PEC) 适体传感器，用于敏感检测血管内皮生长因子 (VEGF)，使用 g-CN 作为光活性材料。DNA 网络为亚甲蓝 (MB) 的固定提供了极好的平台，这可以促进电子通过 DNA 螺旋结构的传输，并抑制 g-CN 产生的电子-空穴对的复合。在存在靶标 VEGF 的情况下，VEGF 与适体之间的识别可以充分破坏 DNA 网络，导致 MB 的释放。因此，原本增强的电子转移过程可以被抑制，导致光电流显著下降。可以在 100fM 至 10nM 的范围内获得与 VEGF 浓度的对数呈良好线性关系的 PEC 信号，检测限为 30 fM。通过触发相应适体桥连 DNA 网络中负载物的释放，我们的概念可以很容易地扩展到用于敏感检测不同靶标的适体传感器的开发。
