Amplified electrochemical sensing of lead ion based on DNA-mediated self-assembly-catalyzed polymerization.
Lead ion (Pb(2+), a heavy metal ion existed every aspect of life) is one of the most important hazards for environment and human health. Herein we design an in-situ amplified electronic monitoring system for sensitive determination of Pb(2+) on Pb(2+)-specific DNAzyme-modified sensing interface. The assay consists of target-triggered cleavage of Pb(2+)-specific DNAzyme, initiator strand-induced DNA hybridization chain reaction, formation of hemin/G-quadruplex -based DNAzyme and its automatically catalyzed polymerization of aniline monomer along the double-stranded DNA. Experimental results indicated that the catalytic currents of the as-produced polyaniline were linearly dependent on target Pb(2+) concentrations from 0.05 to 50nM with a detection limit (LOD) of 32pM. Such a synergistic effect of hybridization chain reaction with DNAzyme-catalyzed polymerization provided a universal platform for sensitive screening of target Pb(2+), thereby holding great promise for application in practice.
Key Laboratory of Analysis and Detection for Food Safety (MOE Fujian Province), Institute of Nanomedicine and Nanobiosensing, Department of Chemistry, Fuzhou University, Fuzhou 350108, PR China.
Bing
B
Zhang
Key Laboratory of Analysis and Detection for Food Safety (MOE Fujian Province), Institute of Nanomedicine and Nanobiosensing, Department of Chemistry, Fuzhou University, Fuzhou 350108, PR China.
Jinfeng
J
Chen
Key Laboratory of Analysis and Detection for Food Safety (MOE Fujian Province), Institute of Nanomedicine and Nanobiosensing, Department of Chemistry, Fuzhou University, Fuzhou 350108, PR China.
Bingqian
B
Liu
Key Laboratory of Analysis and Detection for Food Safety (MOE Fujian Province), Institute of Nanomedicine and Nanobiosensing, Department of Chemistry, Fuzhou University, Fuzhou 350108, PR China. Electronic address: dianping.tang@fzu.edu.cn.
Dianping
D
Tang
D002384:Catalysis; D003217:Conductometry / Q000295:instrumentation*; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D021881:DNA, Catalytic / Q000737:chemistry*; D004566:Electrodes; D004784:Environmental Monitoring / Q000295:instrumentation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D054856:G-Quadruplexes; D007854:Lead / Q000032:analysis* / Q000737:chemistry; D021141:Nucleic Acid Amplification Techniques / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014874:Water Pollutants, Chemical / Q000032:analysis*
D021881:DNA, Catalytic; D014874:Water Pollutants, Chemical; D007854:Lead; D004247:DNA
DNA self-assembly; Electrochemical biosensor; Hemin/G-quadruplex; Lead ion; Polyaniline; Polymerization