State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety (Ministry of Education), College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
Tianjin Key Laboratory of Food Science and Health, School of Medicine, Nankai University, Tianjin 300071, China.
Talanta. 2019 May 1;196:556-562. doi: 10.1016/j.talanta.2019.01.011. Epub 2019 Jan 3.
A novel colorimetric nanosensor has been developed for high sensitive and selective detection of cysteine (Cys) based on the intrinsic oxidase-like activity of cerium nanotube coordinated with aspartic acid (Asp/Ce-NT). Under the function of Asp/Ce-NT, colorimetric reaction of TMB (3,3',5,5'-tetramethylbenzidine) takes place within five minutes without the assistance of additional oxidizing agents (e.g. HO). The oxidase-like activity of Asp/Ce-NT can be modulated by adjusting the ratio of Asp to Ce(NO) during preparation process as well as the chirality of Asp (levogyration/L and dextrorotation/D). Compared with D-Asp/Ce-NT, L-Asp/Ce-NT exhibits more excellent activity which can be specifically depressed by Cys. According to the developed strategy, limit of detection for Cys reaches as low as 33.2 nM. The avoiding use of HO would improve the repeatability and reliability. Nice recoveries from 92.5% to 100.8% are found for Cys detection in serum samples. The developed sensing assay is cost-effective and operated in HO-free and enzyme-free condition, providing an effective rapid detection way for practical application in disease monitoring and diagnosis.
一种新型比色纳米传感器已被开发用于基于铈纳米管与天冬氨酸（Asp/Ce-NT）配位的固有氧化酶样活性对半胱氨酸（Cys）进行高灵敏和选择性检测。在 Asp/Ce-NT 的作用下，TMB（3,3',5,5'-四甲基联苯胺）的比色反应在没有额外氧化剂（如 HO）的情况下在五分钟内发生。通过在制备过程中调节 Asp 与 Ce(NO)的比例以及 Asp 的手性（左旋/L 和右旋/D），可以调节 Asp/Ce-NT 的氧化酶样活性。与 D-Asp/Ce-NT 相比，L-Asp/Ce-NT 表现出更高的活性，其活性可被 Cys 特异性抑制。根据所开发的策略，Cys 的检测限低至 33.2 nM。避免使用 HO 可以提高重复性和可靠性。在血清样品中检测 Cys 时，回收率从 92.5%到 100.8%不等。开发的传感测定法具有成本效益，并且在无 HO 和无酶的条件下进行操作，为疾病监测和诊断的实际应用提供了有效的快速检测方法。
