title: An ultrasensitive DNA biosensor based on covalent immobilization of probe DNA on fern leaf-like α-Fe2O3 and chitosan Hybrid film using terephthalaldehyde as arm-linker.
abstract: In this work, a novel electrochemical DNA biosensor has been developed based on the hybrid film of fern leaf-like α-Fe2O3 microparticles and chitosan (CS). The fern leaf-like α-Fe2O3 microparticles were synthesized via a facile template-free hydrothermal method, and their morphologies were characterized by X-ray diffraction, energy dispersive spectrometry, scanning electron microscope, and transmission electron microscope. Electrochemical characterization assays revealed that the hybrid film modified electrode had remarkable synergistic effects of the large accessible surface area and high electrical conductivity of semiconductive Fe2O3, and the good film stability of CS. Based on the rich amino groups on CS, the CS-Fe2O3 hybrid film was employed as a functional matrix for probe DNA immobilization using terephthalaldehyde (TPA) as a bifunctional arm-linker. The hybridization capacity of the developed biosensor was evaluated with electrochemical impedance spectroscopy (EIS) using [Fe(CN)6](3-/4-) as the indicating probe. A wide dynamic detection range from 1.0 × 10(-14) to 1.0 × 10(-10)M with ultralow detection limit of 5.6 × 10(-15)M was achieved for the target DNA. The hybridization selectivity experiments further revealed that the biosensor could discriminate fully complementary sequences from one-base mismatched, three-base mismatched, and non-complementary sequences. Moreover, the biosensor showed the advantage of good regeneration ability and reproducibility.
authors.affiliation: College of Chemistry and Environment, Fujian Province Key Laboratory of Morden Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou, 363000, P. R. China.
authors.forename: Biyan
authors.initials: B
authors.lastname: Xu
authors.affiliation: Department of Natural Sciences, Shantou Polytechnic, Shantou, 515078, China.
authors.forename: Delun
authors.initials: D
authors.lastname: Zheng
authors.affiliation: College of Chemistry and Environment, Fujian Province Key Laboratory of Morden Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou, 363000, P. R. China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Qiu
authors.affiliation: College of Chemistry and Environment, Fujian Province Key Laboratory of Morden 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 Province Key Laboratory of Morden Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou, 363000, P. R. China.
authors.forename: Shaoxiong
authors.initials: S
authors.lastname: Jiang
authors.affiliation: College of Chemistry and Environment, Fujian Province Key Laboratory of Morden Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou, 363000, P. R. China. Electronic address: axiang236@126.com.
authors.forename: Qingxiang
authors.initials: Q
authors.lastname: Wang
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D048271:Chitosan / Q000737:chemistry*; D004247:DNA / Q000032:analysis / Q000097:blood*; D015342:DNA Probes / Q000737:chemistry; D058266:Dielectric Spectroscopy / Q000379:methods; D005290:Ferric Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D006801:Humans; D061925:Immobilized Nucleic Acids / Q000737:chemistry*; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure; D009693:Nucleic Acid Hybridization / Q000379:methods; D009764:o-Phthalaldehyde / Q000737:chemistry*
chemical_list: D015342:DNA Probes; D005290:Ferric Compounds; D061925:Immobilized Nucleic Acids; C000499:ferric oxide; D009764:o-Phthalaldehyde; D004247:DNA; D048271:Chitosan
keywords: Chitosan; DNA biosensor; Fern leaf-like α-Fe(2)O(3); Hybridization; Terephthalaldehyde