Zhao Lianjing, Wang Jing, Su Dandan, Zhang Yueying, Lu Huiying, Yan Xu, Bai Jihao, Gao Yuan, Lu Geyu
State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China.
Nanoscale. 2020 Oct 1;12(37):19420-19428. doi: 10.1039/d0nr05649a.
The low activity of nanozymes, which work as an alternative to natural enzymes, limits their applications in the fabrication of biosensors, drawing increasing attention aimed at improving their catalytic capacity. In this work, the peroxidase-like activity of MoS2 nanosheets (NSs) was dramatically enhanced through DNA modification, and was 4.3-times higher than that of bare MoS2 NSs. Such an enhancement of catalytic activity was mainly ascribed to the increased affinity of the DNA/MoS2 NSs toward the substrate, TMB, further accelerating electron transfer from TMB to H2O2. On the basis of DNA-tuned MoS2 NS nanozyme activity, a colorimetric sensing platform was developed for the facile detection of carcinoembryonic antigen (CEA) in a sensitive manner. Interestingly, a convenient, affordable, and instrument-free portable test kit was fabricated to visually monitor CEA via rooting the aptamer/MoS2 NS system into an agarose hydrogel. Importantly, our work illuminates the feasibility of using DNA to enhance the catalysis of nanozymes and their application potential in the label-free, portable, and visual detection of aptamer-targeted biomolecules.
纳米酶作为天然酶的替代品，其活性较低，限制了它们在生物传感器制造中的应用，因此提高其催化能力的研究越来越受到关注。在这项工作中，通过DNA修饰显著增强了二硫化钼纳米片（NSs）的过氧化物酶样活性，比未修饰的二硫化钼纳米片高出4.3倍。催化活性的增强主要归因于DNA/二硫化钼纳米片与底物3,3',5,5'-四甲基联苯胺（TMB）的亲和力增加，进一步加速了电子从TMB转移到过氧化氢（H2O2）。基于DNA调节的二硫化钼纳米片纳米酶活性，开发了一种比色传感平台，用于灵敏地检测癌胚抗原（CEA）。有趣的是，通过将适体/二硫化钼纳米片系统固定在琼脂糖水凝胶中，制备了一种方便、经济且无需仪器的便携式检测试剂盒，用于目视监测CEA。重要的是，我们的工作阐明了利用DNA增强纳米酶催化作用的可行性及其在适体靶向生物分子的无标记、便携式和可视化检测中的应用潜力。
