Center for Molecular Recognition and Biosensing, School of Life Sciences, Shanghai University, Shanghai, 200444, China.
Department of Endocrinology, Xuzhou Central Hospital, The Affiliated XuZhou Hospital of Medical College of Southeast University, Xuzhou, 221009, China.
Mikrochim Acta. 2018 Sep 12;185(10):451. doi: 10.1007/s00604-018-2992-2.
The authors describe a significantly improved colorimetric nanoprobe for the determination of transcription factors (TFs). It is making use of click-mediated growth of gold nanoparticles (AuNPs) to amplify the signal-to-noise ratio. Hypoxia-inducible factor-1 (HIF-1) is an important TF that acts as a mediator of cell response to hypoxia. So, the detection of HIF-1 was chosen as the model analyte. Specifically, target HIF-1 is designed to bind to the hypoxia response element within DNA duplex. The click chemistry between the DNA duplex and alkynyl-functionalized AuNPs (AF-AuNPs) is then inhibited because of significant steric hindrance. As a result, the AF-AuNPs grow into larger-sized highly-aggregated irregular nanostructures, which in turn enable colorimetric determination. The ratio of absorbances at 620 and 560 nm increases in the 0.5 to 10 nM HIF-1 concentration range, and the detection limit is 0.27 nM. This is better by a factor of 100 than that of aggregation-based colorimetric assays. The nanoprobe is selective and can be used in complex samples. Conceivably, it may also be extended to the determination of other TFs by simply changing the used DNA duplex. Graphical abstract Schematic of a nanoprobe for detecting hypoxia-inducible factor-1 (HIF-1). Three concepts are involved: the binding of HIF-1 and hypoxia response element, the Cu-catalyzed click chemistry between P1/P2 duplex and alkynyl-functionalized AuNPs (AF-AuNPs), and the AuNPs growth with hydroxylamine and HAuCl.
作者描述了一种显著改进的比色纳米探针，用于测定转录因子 (TFs)。它利用点击介导的金纳米粒子 (AuNPs) 生长来放大信噪比。缺氧诱导因子-1 (HIF-1) 是一种重要的 TF，作为细胞对缺氧反应的介质。因此，选择检测 HIF-1 作为模型分析物。具体来说，目标 HIF-1 设计为与 DNA 双链体中的缺氧反应元件结合。由于空间位阻的影响，DNA 双链体与炔基功能化的 AuNPs (AF-AuNPs) 之间的点击化学反应受到抑制。结果，AF-AuNPs 生长成更大尺寸的高度聚集不规则纳米结构，从而实现比色测定。在 0.5 到 10 nM HIF-1 浓度范围内，620 和 560nm 处的吸光度比值增加，检测限为 0.27 nM。这比基于聚集的比色测定法提高了 100 倍。该纳米探针具有选择性，可用于复杂样品。可以想象，通过简单改变使用的 DNA 双链体，它也可以扩展到其他 TF 的测定。示意图显示了用于检测缺氧诱导因子-1 (HIF-1) 的纳米探针。涉及三个概念：HIF-1 与缺氧反应元件的结合、P1/P2 双链体与炔基功能化的 AuNPs (AF-AuNPs) 之间的 Cu 催化点击化学反应以及羟胺和 HAuCl 引发的 AuNPs 生长。
