Highly sensitive recognition of Pb(2+) using Pb(2+) triggered exonuclease aided DNA recycling

• Published in: Biosensors & bioelectronics Vol. 47; pp. 520 - 523
• Main Authors: Xu, Hui, Xu, Pingping, Gao, Shanmin, Zhang, Shengxiao, Zhao, Xingchun, Fan, Chunhai, Zuo, Xiaolei
• Format: Journal Article
• Language: English
• Published: England 15.09.2013
• Subjects: Biosensing Techniques - methods; DNA, Catalytic - chemistry; Exodeoxyribonucleases - chemistry; Fluorescence; Hazardous Substances - isolation & purification; Hazardous Substances - toxicity; Humans; Lead - isolation & purification; Lead - toxicity; Limit of Detection; Nucleic Acid Hybridization
• ISSN: 1873-4235
• DOI: 10.1016/j.bios.2013.03.062

Here, we have demonstrated an ultra-high sensitive detection platform with the detection limit of 5pM for an environmental toxin-Pb(2+). We designed a Pb(2+) triggered exonuclease aided DNA recycling system to improve the detection sensitivity. In our system, a Pb(2+) dependent 8-17 DNAzyme and its substrate were used to form hybridization duplex. In the presence of Pb(2+), the substrate was cleaved and disassociated from the duplex. Then, the released 8-17 DNAzyme was used as a target of the exonuclease aided DNA recycling system which can amplify the fluorescence signal by recycling the 8-17 DNAzyme continuously. Then, the sensitive Pb(2+) detection are accomplished and the detection limit of Pb(2+) was down to 5pM which is about 1000 times lower than the traditional detection method based on the 8-17 DNAzyme.