title: Hybridization-induced isothermal cycling signal amplification for sensitive electronic detection of nucleic acid.
abstract: This works reports a new signal-on amplification strategy for sensitive electronic detection of nucleic acid based on the isothermal circular strand-displacement polymerization (ICSDP) reaction. The assay mainly involves a hybridization of ferrocene-labeled hairpin DNA with blocker DNA, a strand-displacement process with target DNA, and an ICSDP-based polymerization reaction. The signal is amplified by the labeled ferrocene on the hairpin probe with target recycling. Upon addition of target analyte, the blocker DNA is initially displaced by target DNA from the hairpin/blocker DNA duplex owing to the difference of the folding free energy, then the newly formed target/blocker DNA duplex causes the ICSDP reaction with the aid of the primer and polymerase, and then the released target DNA retriggers the strand-displacement for target recycling. Numerous ferrocene molecules are close to the electrode surface due to the reformation of hairpin DNA, each of which produces an electronic signal within the applied potentials, thereby resulting in the amplification of electrochemical signal. Under the optimal conditions, the ICSDP-based amplification method displays good electrochemical responses for detection of target DNA at a concentration as low as 0.03pM.
authors.affiliation: Key Laboratory of Analysis and Detection for Food Safety (Ministry of Education & Fujian Province), Department of Chemistry, Fuzhou University, Fuzhou 350108, PR China.
authors.forename: Libing
authors.initials: L
authors.lastname: Fu
authors.forename: Dianping
authors.initials: D
authors.lastname: Tang
authors.forename: Junyang
authors.initials: J
authors.lastname: Zhuang
authors.forename: Wenqiang
authors.initials: W
authors.lastname: Lai
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Que
authors.forename: Guonan
authors.initials: G
authors.lastname: Chen
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004247:DNA / Q000737:chemistry / Q000302:isolation & purification*; D055664:Electrochemical Techniques; D005296:Ferrous Compounds / Q000737:chemistry*; D057230:Limit of Detection; D000075163:Metallocenes; D009693:Nucleic Acid Hybridization / Q000379:methods
chemical_list: D005296:Ferrous Compounds; D000075163:Metallocenes; D004247:DNA; C004998:ferrocene