title: Facile construction of a highly sensitive DNA biosensor by in-situ assembly of electro-active tags on hairpin-structured probe fragment.
abstract: An ultrasensitive DNA biosensor has been developed through in-situ labeling of electroactive melamine-Cu(2+) complex (Mel-Cu(2+)) on the end of hairpin-like probe using gold nanoparticles (AuNPs) as the signal amplification platform. The 3'-thiolated hairpin-like probe was first immobilized to the gold electrode surface by the Au-S bond. The AuNPs were then tethered on the free 5'-end of the immobilized probe via the special affinity between Au and the modified -NH2. Followed by, the Mel and Cu(2+) were assembled on the AuNPs surface through Au-N bond and Cu(2+)-N bond, respectively. Due to the surface area and electrocatalytic effects of the AuNPs, the loading amount and electron transfer kinetic of the Mel-Cu(2+) were enhanced greatly, resulting in significantly enhanced electrochemical response of the developed biosensor. Compared with the synthesis process of conventional electroactive probe DNA accomplished by homogeneous method, the method presented in this work is more reagent- and time-saving. The proposed biosensor showed high selectivity, wide linear range and low detection limit. This novel strategy could also be extended to the other bioanalysis platforms such as immunosensors and aptasensors.
authors.affiliation: College of Chemistry and Environment, Fujian Provincial Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, P. R. China.
authors.forename: Qingxiang
authors.initials: Q
authors.lastname: Wang
authors.affiliation: College of Chemistry and Environment, Fujian Provincial Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, P. R. China.
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.affiliation: College of Chemistry and Environment, Fujian Provincial Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, P. R. China.|Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, Fuzhou University, Fuzhou 350116, China.
authors.forename: Jiancong
authors.initials: J
authors.lastname: Ni
authors.affiliation: College of Chemistry and Environment, Fujian Provincial Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, P. R. China.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Liao
authors.affiliation: College of Chemistry and Environment, Fujian Provincial Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, P. R. China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, Fuzhou University, Fuzhou 350116, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Lin
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D003300:Copper / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D015342:DNA Probes / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D005296:Ferrous Compounds / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D000441:Hexanols / Q000737:chemistry; D006801:Humans; D021621:Imaging, Three-Dimensional; D053768:Metal Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D000075163:Metallocenes; D008751:Methylene Blue / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D009690:Nucleic Acid Conformation; D015203:Reproducibility of Results; D017550:Spectroscopy, Fourier Transform Infrared; D013438:Sulfhydryl Compounds / Q000737:chemistry; D014227:Triazines / Q000737:chemistry
chemical_list: C503488:6-mercapto-1-hexanol; D015342:DNA Probes; D005296:Ferrous Compounds; D000441:Hexanols; D000075163:Metallocenes; D013438:Sulfhydryl Compounds; D014227:Triazines; D006046:Gold; D003300:Copper; D004247:DNA; C011907:melamine; D008751:Methylene Blue; C004998:ferrocene