Environmental and Bio-Analytical Laboratories, Department of Chemistry, Sharif University of Technology, P.O. Box 11365-9516, Tehran, Iran.
Pilot Nanobiotechnology Department, Pasteur Institute of Iran, P.O. Box 13169-43551, Tehran, Iran.
Mikrochim Acta. 2019 Nov 15;186(12):785. doi: 10.1007/s00604-019-3956-x.
A turn-on fluorometric assay is described for determination of the activity of enzyme telomerase. For this purpose, graphene quantum dots (GQDs) were first modified with the telomeric sequence (5'-amino-AATCCGTCGAGCAGAGTT-3') via a condensation reaction. Injection of graphene oxide causes instant quenching of the blue fluorescence of the GQDs. Addition of cell extract containing telomerase, triggers the extension of telomer via addition of specific sequence (TTAGGG)n to its 3' end. Fluorescence, best measured at excitation/emission wavelengths of 390/446 nm, is subsequently restored due to folding of the extended telomeric sequence into G-quadruplex structure. The method was applied to the determination of telomerase activity in crude cell extracts of as little as 10 HeLa cells. The linear dynamic range extends from 10 to 6500 cells. Graphical abstractIn this study, a new turn-on graphene quantum dotm and graphene oxide based fluorometric assay is developed for the determination of telomerase activity.
一种用于测定端粒酶活性的荧光分析方法。为此，通过缩合反应将端粒序列（5'-氨基-AATCCGTCGAGCAGAGTT-3'）首先修饰在石墨烯量子点（GQDs）上。氧化石墨烯的注入会立即猝灭 GQDs 的蓝色荧光。加入含有端粒酶的细胞提取物，通过在其 3'末端添加特定序列（TTAGGG）n 来触发端粒的延伸。荧光，最好在激发/发射波长为 390/446nm 下测量，由于延伸的端粒序列折叠成 G-四链体结构，荧光随后恢复。该方法已应用于从少至 10 个 HeLa 细胞的粗细胞提取物中测定端粒酶活性。线性动态范围从 10 到 6500 个细胞。
