College of Materials and Energy, South China Agricultural University, Guangzhou, 510642, China.
College of Materials and Energy, South China Agricultural University, Guangzhou, 510642, China; Guangdong Institute of Microbiology, Guangzhou, 510070, China.
Anal Chim Acta. 2019 Apr 25;1054:128-136. doi: 10.1016/j.aca.2018.12.018. Epub 2018 Dec 15.
Recently, mimic enzymes have obtained particular interest by their high activity, stability, and biocompatibility. In this work, by coupling copper hydroxide nanozyme and G-quadruplex/hemin DNAzyme to form a double-integrated mimic enzyme, a visual, sensitive and selective immunosensor was established to detect microcystin-LR (MC-LR). In this immunoassay, the microplates were modified with core-shell silica/nickel silicate as the substrate to capture MC-LR antigens. Then, Cu(OH) nanocages with fine regulation were used as the label to capture the secondary antibody for immunoreaction and the DNA primer for propagation, followed by using hybridization chain reaction to amplify the DNA primer, thus numerous DNAzymes (G-quadruplex/hemin) can be formed on the surface of Cu(OH) nanocages with the aid of hemin. Such double-integrated mimic enzyme including Cu(OH) nanozymes and DNAzymes showed excellent peroxidase activity for the chromogenic reaction of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), which realized the visual detection of MC-LR in the range from 0.007 to 75 μg/L with the detection limit of 6 ng/mL, and thus provided the probability for the portable assessment of MC-LR in real sample.
近年来，模拟酶因其高活性、高稳定性和良好的生物相容性而受到特别关注。在这项工作中，通过将氧化铜纳米酶和 G-四链体/血红素 DNA 酶偶联形成双集成模拟酶，建立了一种可视化、敏感和选择性的免疫传感器来检测微囊藻毒素-LR（MC-LR）。在该免疫分析中，使用核壳结构的硅/硅酸镍作为基底来修饰微孔板，以捕获 MC-LR 抗原。然后，使用精细调控的 Cu(OH)纳米笼作为标签，用于捕获二次抗体进行免疫反应和 DNA 引物进行扩增，随后通过杂交链式反应来扩增 DNA 引物，从而在血红素的辅助下，在 Cu(OH)纳米笼表面形成大量的 DNA 酶（G-四链体/血红素）。这种双集成模拟酶包括氧化铜纳米酶和 DNA 酶，表现出优异的过氧化物酶活性，用于 2,2'-联氮双（3-乙基苯并噻唑啉-6-磺酸）（ABTS）的显色反应，实现了 MC-LR 在 0.007 至 75μg/L 范围内的可视化检测，检测限为 6ng/mL，从而为实际样品中 MC-LR 的便携评估提供了可能性。
