title: Electrochemical DNA biosensor based on the proximity-dependent surface hybridization assay.
abstract: This paper describes a novel electrochemical DNA (E-DNA) biosensor for simple, rapid, and specific detection of nucleic acids based on the proximity-dependent surface hybridization assay. This E-DNA biosensor was constructed by self-assembly of a 3' short thiolated capture probe on the gold electrode. DNA detection was realized by outputting a remarkable redox current of the 5' ferrocene (Fc) tail labeled probe. When the target DNA was introduced into the system, it was complementary to the 5' Fc labeled probe at the one-half-segment and complementary to the 3' short thiolated capture probe at the other half-segment, resulting in forming a stable duplex complex. As a result, the Fc probe was proximate to the electrode surface, and the Faradaic current was observed. This E-DNA biosensor was proved to have a low detection limit (1 fM) and a wide dynamic range (from 1 fM to 1 nM) due to the stable hybridization mode. In addition, the sensing system could discriminate the complementary sequence from mismatch sequences, with high sensitivity, stability, and reusability.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P. R. China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Haibo
authors.initials: H
authors.lastname: Wang
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Jiang
authors.forename: Guo-Li
authors.initials: GL
authors.lastname: Shen
authors.forename: Ru-Qin
authors.initials: RQ
authors.lastname: Yu
authors.forename: Jinghong
authors.initials: J
authors.lastname: Li
mesh_terms: D001483:Base Sequence; D001681:Biological Assay; D015374:Biosensing Techniques / Q000379:methods*; D004247:DNA / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods; D004563:Electrochemistry / Q000379:methods; D005296:Ferrous Compounds / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D057230:Limit of Detection; D000075163:Metallocenes; D018625:Microscopy, Atomic Force; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization / Q000379:methods*; D009696:Nucleic Acids / Q000737:chemistry*; D010084:Oxidation-Reduction; D017422:Sequence Analysis, DNA
chemical_list: D005296:Ferrous Compounds; D000075163:Metallocenes; D009696:Nucleic Acids; D006046:Gold; D004247:DNA; C004998:ferrocene