Abstract
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.
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•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.