Nanozyme-catalysed CRISPR-Cas12a system for the preamplification-free colorimetric detection of lead ion

• Published in: Analytica chimica acta 2023-02, Vol.1243, p.340827, Article 340827
• Main Authors: Xu, Shiqi, Wang, Songtao, Guo, Ling, Tong, Yuqin, Wu, Lina, Huang, Xingxu
• Format: Article
• Language: English
• Subjects: Biosensing Techniques; Colorimetry; CRISPR-Cas Systems; CRISPR-Cas12a; Detection; DNA, Catalytic; Lead; Lead ion; Manganese Compounds; MnO2 nanorods; Oxides
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2023.340827

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 (Pb2+) based on the assistance of DNAzyme and nanozyme instead of preamplification. The recognition between GR-5 DNAzyme and Pb2+ could trigger the CRISPR-Cas12a system. MnO2 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 Pb2+ 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 Pb2+ in food samples indicating good accuracy and anti-interference ability. [Display omitted] •The MnO2 nanozyme used as both catalyst and signal probe for CRISPR system.•MnO2 nanozyme expanded the spectrum of targets for preamplification-free detection.•The system was used to detect Pb2+ in oil samples indicating the feasibility.