College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan 250014, China.
Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOE; Shandong Key Laboratory of Biochemical Analysis; Key Laboratory of Analytical Chemistry for Life Science in Universities of Shandong; and College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, P. R. China.
Anal Chem. 2021 Feb 9;93(5):2974-2981. doi: 10.1021/acs.analchem.0c04904. Epub 2021 Jan 21.
Metal-organic gels (MOGs) are new soft materials with the characteristics of high colloidal stability, superb luminescence properties, and facile synthesis. Herein, we develop for the first time a host-guest interaction-based and MOG-based biosensor with aggregation-induced electrochemiluminescence (ECL) enhancement for M.SssI methyltransferase (M.SssI MTase) assay. This biosensor employs a MOG as the luminophor and potassium persulfate as the coreactant, and the formation of the Ag-MOG from the aggregation of silver nanoclusters can induce significant ECL enhancement. Two complementary single-stranded DNAs (ssDNAs, i.e., biotinylated DNA-1 and Fc-labeled DNA-2) that contain specific recognition sequence 5'-CCGG-3' can form a double-stranded DNA (dsDNA) probe. In the absence of M.SssI MTase, the dsDNA probe will be digested by restriction endonuclease HpaII, leading to the release of Fc from magnetic beads (MBs). The β-CD can specifically recognize the released Fc through guest-host interaction, resulting in the quenching of an ECL signal. In contrast, the presence of M.SssI MTase enables the formation of fully methylated dsDNA, which cannot be cleaved by HpaII, making Fc remain on the MB surface and consequently generating an improved ECL signal. This biosensor can specifically detect M.SssI MTase with a linear range of 0.05-100 U mL and a limit of detection of 3.5 × 10 U mL, and it enables accurate detection of M.SssI MTase in human serum. In addition, it can be used for inhibitor screening, with wide applications in drug discovery and disease diagnosis.
金属有机凝胶（MOG）是一种新型的软材料，具有高胶体稳定性、出色的发光性能和易于合成的特点。本文首次开发了一种基于主客体相互作用和 MOG 的生物传感器，用于 M.SssI 甲基转移酶（M.SssI MTase）测定，具有聚集诱导电化学发光（ECL）增强的特性。该生物传感器以 MOG 为发光体，过硫酸钾为共反应物，银纳米簇的聚集形成的 Ag-MOG 可引起显著的 ECL 增强。两条互补的单链 DNA（ssDNA，即生物素化 DNA-1 和 Fc 标记的 DNA-2），含有特定识别序列 5'-CCGG-3'，可形成双链 DNA（dsDNA）探针。在没有 M.SssI MTase 的情况下，dsDNA 探针将被限制性内切酶 HpaII 消化，导致 Fc 从磁珠（MBs）上释放。β-CD 可以通过主客体相互作用特异性识别释放的 Fc，从而猝灭 ECL 信号。相反，存在 M.SssI MTase 可使完全甲基化的 dsDNA 形成，其不能被 HpaII 切割，使 Fc 留在 MB 表面，从而产生增强的 ECL 信号。该生物传感器可以特异性检测 M.SssI MTase，线性范围为 0.05-100 U mL，检测限为 3.5 × 10 U mL，可在人血清中准确检测 M.SssI MTase。此外，它可用于抑制剂筛选，在药物发现和疾病诊断中有广泛的应用。
