State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering , Hunan University , Changsha 410082 , P. R. China.
School of Chemistry and Biological Engineering , Changsha University of Science and Technology , Changsha 410114 , P. R. China.
ACS Appl Mater Interfaces. 2019 Feb 27;11(8):7792-7799. doi: 10.1021/acsami.8b21727. Epub 2019 Feb 15.
A novel sensing platform for recognition and quantification of target microRNAs (miRNAs) was developed by combining an amylase-trapped DNA hydrogel, multicomponent nucleic acid enzymes (MNAzymes), and a portable glucometer (PGM) readout. First, the amylase was encapsulated inside the DNA hydrogel and physically separated from its substrate of amylose, which was in a solution outside the hydrogel. After addition of the target miRNA, the activity of the MNAzyme was restored, which cuts off the substrate linker strand. The active MNAzyme can catalytically act upon multiple substrate strands through diffusion, leading to the collapse of the hydrogel and the release of amylase, which catalyzes the hydrolysis of amylose to produce a large amount of glucose and generate a high PGM signal. The smart usage of the PGM enables simple portable detection of miR-21, with a detection limit as low as 0.325 fmol. Additionally, through the simple rational design of the target-binding sensor arms, the amylase-trapped DNA hydrogel sensing platform was successfully applied in the detection of multiple endogenous miRNAs (including miR-21, miR-335, miR-155, and miR-122) extracted from HeLa cells, HepG2 cells, MCF-7 cells, and L02 cells.
一种用于识别和定量靶微小 RNA（miRNA）的新型传感平台是通过将淀粉酶捕获的 DNA 水凝胶、多组分核酸酶（MNAzyme）和便携式血糖仪（PGM）读数相结合而开发的。首先，将淀粉酶包封在 DNA 水凝胶内，并与水凝胶外溶液中的其底物直链淀粉物理分离。加入靶 miRNA 后，MNAzyme 的活性得到恢复，它切断了底物连接链。活性 MNAzyme 可以通过扩散作用对多个底物链进行催化作用，导致水凝胶崩溃并释放淀粉酶，淀粉酶催化直链淀粉水解产生大量葡萄糖并产生高 PGM 信号。智能使用 PGM 能够简单便携地检测 miR-21，检测限低至 0.325 fmol。此外，通过目标结合传感器臂的简单合理设计，成功将淀粉酶捕获的 DNA 水凝胶传感平台应用于从 HeLa 细胞、HepG2 细胞、MCF-7 细胞和 L02 细胞中提取的多种内源性 miRNA（包括 miR-21、miR-335、miR-155 和 miR-122）的检测。
