title: Assistant deoxyribonucleic acid recycling with Zn(2+) and molecular beacon for electrochemical detection of deoxyribonucleic acid via target-triggered assembly of mutated DNAzyme.
abstract: A novel enzyme-free amplification strategy was designed for sensitive electrochemical detection of deoxyribonucleic acid (DNA) based on Zn(2+) assistant DNA recycling via target-triggered assembly of mutated DNAzyme. A gold electrode was used to immobilize molecular beacon (MB) as the recognition probe and perform the amplification procedure. In the presence of target DNA, the hairpin probe 1 was opened, and the DNAzyme was liberated from the caged structure. The activated DNAzyme first hybridized and then cleaved the MB in the presence of cofactor Zn(2+). After cleavage, the MB was cleaved into two pieces and the ferrocene (Fc) labeled piece dissociated from the gold electrode, thus obviously decreasing the Fc signal and forming a free DNAzyme strand. Finally, each target-induced activated DNAzyme underwent many cycles to trigger the cleavage of many MB substrates. Therefore, the peak current of Fc dramatically decreased to approximately zero. The strategy showed a detection limit at 35 fM levels, which was about 2 orders of magnitude lower than that of the conventional hybridization without Zn(2+)-based amplification. The Zn(2+) assistant DNA recycling offers a versatile platform for DNA detection in a cost-effective manner, and has a promising application in clinical diagnosis.
authors.affiliation: Key Laboratory of Radioactive Geology and Exploration Technology Fundamental Science for National Defense, East China Institute of Technology, Nanchang 344000, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Qian
authors.affiliation: Key Laboratory of Radioactive Geology and Exploration Technology Fundamental Science for National Defense, East China Institute of Technology, Nanchang 344000, China.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory of Target Drug and Clinical Application, School of Pharmacy, Xuzhou Medical College, Xuzhou 221004, China. Electronic address: jsxzgfl@sina.com.
authors.forename: Fenglei
authors.initials: F
authors.lastname: Gao
mesh_terms: D004247:DNA / Q000032:analysis*; D021881:DNA, Catalytic / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D055664:Electrochemical Techniques; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D009154:Mutation / Q000235:genetics; D015032:Zinc / Q000737:chemistry*
chemical_list: D021881:DNA, Catalytic; D006046:Gold; D004247:DNA; D015032:Zinc
keywords: Amplification; DNAzyme; Deoxyribonucleic acid; Electrochemical