Lab of Low-Dimensional Materials Chemistry, Key Laboratory for Ultrafine Materials of Ministry of Education, Frontier Science Center of Materials Biology and Dynamic Chemistry, Shanghai Engineering Research Center of Hierarchical Nanomaterials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, 200237, China.
Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, 832003, P.R. China.
Biomater Sci. 2024 Oct 8;12(20):5266-5273. doi: 10.1039/d4bm01018c.
Rapid and accurate detection of 7-methylguanine (mGua), a biomarker reflecting the degree of DNA methylation that occurs before or in the early stage of cancer, is of particular significance but remains a great challenge. Herein, a luminescent lanthanide-based covalent organic framework (Ln-COF) probe, namely DPA/Eu@ETTA-DHTA, is designed for the first time for the identification of mGua by assembling pyridine-2,6-dicarboxylic acid (DPA) as both an energy donor and a recognition molecule and Eu ions as signal reporters into a stable COF matrix with high porosity and available binding sites. Significantly, the characteristic luminescence of Eu ions can be turned on by the grafted DPA in the COF probe and effectively quenched by the addition of mGua a competitive absorption process, thus achieving the sensing of mGua. Such a Ln-COF-based fluorescent platform presents high selectivity and a rapid response (<1 min) to mGua with a low detection limit (μM level) even in the presence of the main coexisting species in urine, allowing it to serve as a potentially practical probe for point-of-care monitoring of the level of mGua in human urine specimens. This study provides a convenient, time-saving, and economical approach for visual detection of mGua, and opens up new perspectives for the design of a luminescent COF-based probe for DNA methylation evaluation in diagnostics.
快速准确地检测 7-甲基鸟嘌呤（mGua），一种反映癌症发生前或早期 DNA 甲基化程度的生物标志物，具有特别重要的意义，但仍然是一个巨大的挑战。在此，我们首次设计了一种基于镧系元素的发光共价有机框架（Ln-COF）探针，即 DPA/Eu@ETTA-DHTA，通过将吡啶-2,6-二羧酸（DPA）作为能量供体和识别分子，以及 Eu 离子作为信号报告基团，组装到具有高孔隙率和可用结合位点的稳定 COF 基质中，用于 mGua 的识别。值得注意的是，COF 探针中接枝的 DPA 可以打开 Eu 离子的特征发光，并且可以通过加入 mGua 进行有效猝灭——这是一个竞争吸收过程，从而实现对 mGua 的传感。这种基于 Ln-COF 的荧光平台对 mGua 具有高选择性和快速响应（<1 分钟），检测限低（μM 级），即使在尿液中的主要共存物质存在下也是如此，使其成为一种潜在的实用探针，可用于即时检测人尿液样本中 mGua 的水平。本研究为 mGua 的可视化检测提供了一种方便、省时和经济的方法，并为基于发光 COF 的用于诊断中 DNA 甲基化评估的探针设计开辟了新的视角。
