State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University , Changsha 410082, People's Republic of China.
Anal Chem. 2016 Jun 7;88(11):5981-7. doi: 10.1021/acs.analchem.6b00999. Epub 2016 May 17.
To date, a few of DNAzyme-based sensors have been successfully developed in living cells; however, the intracellular aptazyme sensor has remained underdeveloped. Here, the first aptazyme sensor for amplified molecular probing in living cells is developed. A gold nanoparticle (AuNP) is modified with substrate strands hybridized to aptazyme strands. Only the target molecule can activate the aptazyme and then cleave and release the fluorophore-labeled substrate strands from the AuNP, resulting in fluorescence enhancement. The process is repeated so that each copy of target can cleave multiplex fluorophore-labeled substrate strands, amplifying the fluorescence signal. Results show that the detection limit is about 200 nM, which is 2 or 3 orders of magnitude lower than that of the reported aptamer-based adenosine triphosphate (ATP) sensors used in living cells. Furthermore, it is demonstrated that the aptazyme sensor can readily enter living cells and realize intracellular target detection.
迄今为止，已有一些基于 DNA 酶的传感器在活细胞中成功开发；然而，细胞内适体传感器的发展仍然滞后。在此，开发了第一个用于在活细胞中进行放大分子探测的适体传感器。金纳米粒子 (AuNP) 用与适体链杂交的底物链进行修饰。只有目标分子才能激活适体，然后从 AuNP 上切割并释放荧光标记的底物链，从而增强荧光。这个过程会重复进行，使得每个目标分子都能切割多份荧光标记的底物链，从而放大荧光信号。结果表明，检测限约为 200 nM，比已报道的用于活细胞的基于适配体的三磷酸腺苷 (ATP) 传感器低 2 到 3 个数量级。此外，还证明了该适体传感器可以轻易进入活细胞并实现细胞内目标检测。
