title: A novel mediator-free biosensor based on co-intercalation of DNA and hemoglobin in the interlayer galleries of alpha-zirconium phosphate.
abstract: A novel mediator-free biosensor was constructed by the co-intercalation of negatively charged DNA and positively charged hemoglobin (Hb) in the interlayer galleries of layered alpha-zirconium phosphate (alpha-ZrP) with the delamination-assembly procedure at pH 5.5. X-ray diffraction and field-emission scanning electron microscopy results revealed the featured layered structure for the re-assembled DNA/Hb/alpha-ZrP composite. Infrared spectroscopy and circular dichroism results confirmed the coexistence of Hb and DNA in the composite and the considerably retained protein conformation of intercalated Hb. The direct electron transfer of Hb was facilitated by the co-intercalation of DNA and Hb. Because of the synergistic effect of alpha-ZrP host and co-intercalated DNA guest, the DNA/Hb/alpha-ZrP modified electrode exhibited good electrocatalytic response to H(2)O(2) with higher sensitivity of 0.79 A M(-1) cm(-2) and lower detection of 4.28x10(-7) M in the linear range of 7.28x10(-7) to 9.71x10(-5) M. Furthermore, the electrocatalytic activity of Hb in the DNA/Hb/alpha-ZrP composite retained at high temperature (85 degrees C) or in the presence of organic solvent (CH(3)CN), which could be the protection of alpha-ZrP nanosheets.
authors.affiliation: Key Laboratory of Analytical Chemistry for Life Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, PR China.
authors.forename: Limin
authors.initials: L
authors.lastname: Liu
authors.forename: Bo
authors.initials: B
authors.lastname: Shen
authors.forename: Jianjun
authors.initials: J
authors.lastname: Shi
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.forename: Guo-Yuan
authors.initials: GY
authors.lastname: Lu
authors.forename: Jun-Jie
authors.initials: JJ
authors.lastname: Zhu
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002384:Catalysis; D002417:Cattle; D004247:DNA / Q000737:chemistry*; D055664:Electrochemical Techniques; D006454:Hemoglobins / Q000737:chemistry*; D006861:Hydrogen Peroxide; D007364:Intercalating Agents; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures; D033362:Powder Diffraction; D017550:Spectroscopy, Fourier Transform Infrared; D015040:Zirconium
chemical_list: D006454:Hemoglobins; D007364:Intercalating Agents; C027006:zirconium phosphate; D004247:DNA; D006861:Hydrogen Peroxide; D015040:Zirconium