Sheng Anzhi, Wang Pei, Yang Jingyi, Tang Longfei, Chen Feng, Zhang Juan
Research Center of Molecular Recognition and Biosensing, School of Life Sciences, Shanghai University, Shanghai 200444, P. R. China.
Department of Orthopedic, Spinal Pain Research Institute, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P. R. China.
Anal Chem. 2021 Mar 16;93(10):4676-4681. doi: 10.1021/acs.analchem.1c00371. Epub 2021 Mar 2.
With hydrophilic surface and high density of functional groups, MXene can efficiently adsorb single-stranded DNA to enhance target-induced strand release and quench the fluorescence. Herein, MXene is coupled with CRISPR-Cas12a to sensitively detect LPS and bacteria. Specifically, the aptamer is well designed to initiate the trans-cleavage activity of CRISPR-Cas12a to indiscriminately cleave single-stranded DNA, resulting it to be far away from MXene and the recovery of fluorescence. The target can effectually induce the release of the aptamer strand from the hybrid duplex with the assistance of MXene. The formed aptamer/target complex will inhibit the activation of CRISPR-Cas12a and its trans-cleavage on single-stranded DNA. The established method can selectively and sensitively quantify LPS and Gram-negative bacteria in different samples with detection limits of 11 pg/mL and 23 CFU/mL, respectively. Our study provides a new insight for exploration of universal analytical methods based on MXene coupled with CRISPR-Cas12a.
MXene具有亲水性表面和高密度的官能团，能够高效吸附单链DNA，增强靶标诱导的链释放并淬灭荧光。在此，MXene与CRISPR-Cas12a偶联以灵敏地检测LPS和细菌。具体而言，适配体经过精心设计，可启动CRISPR-Cas12a的反式切割活性，从而无差别地切割单链DNA，使其远离MXene并恢复荧光。在MXene的协助下，靶标能够有效地诱导适配体链从杂交双链体中释放出来。形成的适配体/靶标复合物会抑制CRISPR-Cas12a的激活及其对单链DNA的反式切割。所建立的方法能够分别以11 pg/mL和23 CFU/mL的检测限，选择性且灵敏地定量不同样品中的LPS和革兰氏阴性菌。我们的研究为基于MXene与CRISPR-Cas12a偶联的通用分析方法探索提供了新的见解。
