School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210023, China.
National Engineering Research Center of Solid-state Brewing, Luzhou, 646000, China.
Anal Chim Acta. 2023 Feb 22;1243:340827. doi: 10.1016/j.aca.2023.340827. Epub 2023 Jan 12.
CRISPR-based detection was often based on the target preamplification to realize the high sensitivity. Here, we prepared a CRISPR-Cas12a system for the colorimetric detection of lead ion (Pb) based on the assistance of DNAzyme and nanozyme instead of preamplification. The recognition between GR-5 DNAzyme and Pb could trigger the CRISPR-Cas12a system. MnO nanozymes connected with magnetic beads through single stranded DNA were prepared as the colorimetric signal probes and catalyst of CRISPR-Cas12a system for the strong oxidase-like activity inducing the color change of 3,3',5,5'-tetramethylbenzidine. The nanozyme-catalysed CRISPR-Cas12a system could be used to detect Pb through the color change with high specificity and sensitivity. The linear range of this approach was 0.8 nM-2500 nM, with a limit of detection of 0.54 nM. This method was applied for the detection of the Pb in food samples indicating good accuracy and anti-interference ability.
基于 CRISPR 的检测通常基于目标预扩增来实现高灵敏度。在这里，我们准备了一个基于 CRISPR-Cas12a 系统，用于比色法检测基于 DNA 酶和纳米酶而不是预扩增的铅离子 (Pb)。GR-5 DNA 酶与 Pb 之间的识别可以触发 CRISPR-Cas12a 系统。通过单链 DNA 将连接到磁性珠上的 MnO 纳米酶作为比色信号探针和 CRISPR-Cas12a 系统的催化剂，用于强过氧化物酶样活性诱导 3,3',5,5'-四甲基联苯胺的颜色变化。纳米酶催化的 CRISPR-Cas12a 系统可以通过颜色变化进行高特异性和灵敏度的 Pb 检测。该方法的线性范围为 0.8 nM-2500 nM，检测限为 0.54 nM。该方法用于检测食品样品中的 Pb，表明具有良好的准确性和抗干扰能力。
