title: Ultrasensitive signal-on DNA biosensor based on nicking endonuclease assisted electrochemistry signal amplification.
abstract: Combining the advantages of signal-on strategy and nicking endonuclease assisted electrochemistry signal amplification (NEAESA), a new sensitive and signal-on electrochemical DNA biosensor for the sequence specific DNA detection based on NEAESA has been developed for the first time. A Hairpin-shape probe (HP), containing the target DNA recognition sequence, is thiol-modified at 5' end and immobilized on gold electrode via Au-S bonding. Subsequently, the HP modified electrode is hybridized with target DNA to form a duplex. Then the nicking endonuclease is added and nicks the HP strand in the duplex. After nicking, 3'-ferrocene (Fc)-labeled part complementary probe (Fc-PCP) is introduced on the electrode surface by hybridizing with the thiol-modified HP fragment, which results in the generation of electrochemical signal. Hence, the DNA biosensor is constructed successfully. The present DNA biosensor shows a wide linear range of 5.0×10(-13)-5.0×10(-8)M for detecting target DNA, with a low detection limit of 0.167pM. The proposed strategy does not require any amplifying labels (enzymes, DNAzymes, nanoparticles, etc.) for biorecognition events, which avoids false-positive results to occur frequently. Moreover, the strategy has the benefits of simple preparation, convenient operation, good selectivity, and high sensitivity. With the advantages mentioned above, this simple and sensitive strategy has the potential to be integrated in portable, low cost and simplified devices for diagnostic applications.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, PR China.
authors.forename: Zhongyuan
authors.initials: Z
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Shuyun
authors.initials: S
authors.lastname: Zhu
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Lianzhe
authors.initials: L
authors.lastname: Hu
authors.forename: Saima
authors.initials: S
authors.lastname: Parveen
authors.forename: Guobao
authors.initials: G
authors.lastname: Xu
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods* / Q000706:statistics & numerical data; D004247:DNA / Q000032:analysis* / Q000235:genetics; D015342:DNA Probes / Q000737:chemistry / Q000235:genetics; D003850:Deoxyribonuclease I; D055664:Electrochemical Techniques; D004800:Enzymes, Immobilized; D009690:Nucleic Acid Conformation
chemical_list: D015342:DNA Probes; D004800:Enzymes, Immobilized; D004247:DNA; D003850:Deoxyribonuclease I