Key Laboratory of Research and Utilization of Ethnomedicinal Plant Resources of Hunan Province, College of Biological and Food Engineering, Huaihua University, Huaihua, 418008, P. R. China.
Jiangxi Provincial Key Laboratory of Natural and Biomimetic Drugs Research, College of Chemistry and Materials, Jiangxi Normal University, Nanchang, 330022, P. R. China.
Mikrochim Acta. 2024 Oct 5;191(11):646. doi: 10.1007/s00604-024-06710-9.
A reusable fluorescent nanoprobe was developed using DNA-functionalized metal-organic framework (MOF) for ratiometric detection of Hg. We utilized a zirconium-based MOF (UiO-66) to encapsulate tris(bipyridine) ruthenium(II) chloride (Ru(bpy)), resulting in Ru(bpy)@UiO-66 (RU) with red fluorescence. The unsaturated metal sites in UiO-66 facilitate the attachment of thymine-rich single-strand DNA (T-ssDNA) through Zr-O-P bond, producing T-ssDNA-functionalized RU complex (RUT). The T-ssDNA selectively binds to Hg, forming stable T-Hg-T base pairs and folding into double-stranded DNA, which permits the intercalation of SYBR Green I (SGI) and activates its green fluorescence. In the presence of Hg, SGI fluorescence increases in a dose-dependent manner, while Ru(bpy) fluorescence remains constant. This fluorescence contrast enables RUT to serve as an effective ratiometric nanoprobe for Hg detection, with a detection limit of 3.37 nM. Additionally, RUT demonstrates exceptional reusability due to the ability of cysteine to remove Hg, given its stronger affinity for thiol groups. The RUT was successfully applied to detect Hg in real water samples. This work advances the development of ratiometric fluorescence nanoprobe based on DNA-functionalized MOFs.
一种可重复使用的荧光纳米探针，使用 DNA 功能化的金属有机骨架（MOF）用于 Hg 的比率检测。我们利用基于锆的 MOF（UiO-66）封装三（联吡啶）钌（II）氯化物（Ru(bpy)），得到具有红色荧光的 Ru(bpy)@UiO-66（RU）。UiO-66 中的不饱和金属位点通过 Zr-O-P 键促进胸腺嘧啶丰富的单链 DNA（T-ssDNA）的附着，产生 T-ssDNA 功能化的 RU 配合物（RUT）。T-ssDNA 选择性地与 Hg 结合，形成稳定的 T-Hg-T 碱基对并折叠成双链 DNA，允许 SYBR Green I（SGI）插入并激活其绿色荧光。在存在 Hg 的情况下，SGI 荧光呈剂量依赖性增加，而 Ru(bpy) 荧光保持不变。这种荧光对比使得 RUT 成为 Hg 检测的有效比率纳米探针，检测限为 3.37 nM。此外，由于半胱氨酸对巯基的亲和力更强，能够去除 Hg，RUT 表现出出色的可重复使用性。RUT 成功应用于实际水样中 Hg 的检测。这项工作推进了基于 DNA 功能化 MOF 的比率荧光纳米探针的发展。
