Label-free DNAzyme assays for dually amplified and one-pot detection of lead pollution

• Published in: Journal of hazardous materials Vol. 406; p. 124790
• Main Authors: Zhang, Yong, Wu, Chengyong, Liu, Hongxin, Khan, Mohammad Rizwan, Zhao, Zhifeng, He, Guiping, Luo, Aimin, Zhang, Jiaqi, Deng, Ruijie, He, Qiang
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.03.2021
• Subjects: Amplification; Animals; Biosensing Techniques; DNA, Catalytic; DNAzyme; Drinking Water; Environmental Pollutants - analysis; Fishes; Fluorescence assay; Food Contamination; Ions; Label-free; Lead - analysis; Lead pollution; Limit of Detection; Milk; Amplification; DNAzyme; Label-free; Lead pollution; Fluorescence assay
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2020.124790

Lead pollution in water and soil often transfers to food, advocating tools for on-site detection of lead pollution to ensure both environmental and food safety. We proposed a label-free, dually amplified and homogeneous DNAzyme assay for sensitive and one-pot detection of lead pollution. Instead of using chemically modified DNA substrate, a structure-response digestion process was introduced to monitor Pb2+ presence-induced cleavage process of unlabeled substrate, further amplifying the response signals and eliminating the use of labeled DNA probes. The DNAzyme assay allowed to detect Pb2+ as low as 0.12 nM and endued a dynamic range from 0.1 nM to 30 nM. In addition, it can specifically identify Pb2+ among other metal ions. We demonstrated that the DNAzyme assay can precisely detect Pb2+ in tap water, milk and fish. Thus, the DNAzyme assay is promising for on-site monitoring lead pollution risk and ensuring environmental and food safety. [Display omitted] •Dually amplification allows to highly sensitive detection of Pb2+.•The DNAzyme assay allows to label-free and one-pot detection of Pb2+.•The DNAzyme assay can strictly discriminate Pb2+ among interfering ions.•Lead pollution in milk and fish was accurately detected.