| Bio-sensing technology can capture a variety of biological information in vivo and provide basic human physiology, pathology-related information for the clinical diagnosis and the basic biomedical research. Therefore, the research related to this subject has become very urgent. The development of the new functional bio-medical sensors will provide a historic opportunity for comprehensively promoting the science progress of the human health. The emergence of nanotechnology opened a new heaven and earth for the development of the research in this field and the construction of the wonderful nano-bionic interface had promoted the development of the biomedical biosensor to a new height. The research of nano-bionic interface is an interdisciplinary field of nanotechnology and life science, which can be used to study the structure and function of biological macromolecules, macromolecule complexes and cell at the molecular level in the nanometer scale space, to resolve the basic problem about nanotechnology applications in the biomedical field and develop new technologies and new methods. A variety of bio-sensors have been constructed on the nano-bionic interface by many countries'scientists, and used for the detection of hepatitis, leukemia, AIDS, SARS and so on. However, these studies are still in the initial stage. Exploring for convenient and fast methods of preparing and assembling nano-materials, building functional bionic nano-interfaces and developing new bio-sensing technology will become a co-endeavor direction of material scientist, analytical chemists, medical scientists and so on.In this paper, the new nano-bionic interfaces were constructed on the surface of glassy carbon electrode (GCE) by assembly or combination of some materials, such as electric polymer, carbon nanotubes, alloy nano-particles and nano-oxides, using the methods of electrodeposition, electro-polymerization, covalent combination, adsorption or casting the sample solution on the surface. The properties of the bio-interface and the electrochemical behaviors of DNA, enzymes and little medicine molecules were characterized by many methods and technologies, such as scanning electronic microscopy (SEM), transition electronic microscopy (TEM), X-ray powder diffraction (XRD) and ultraviolet-visible (UV-vis) spectrophotometry, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), differential pulse voltammetry (DPV), chronoamperometry and chronocoulometry. The main content is as follows:(1) The Fe@Fe2O3 core-shell nanonecklaces, Fe@Fe2O3 core-shell wires and Cu2O nanocubes were synthesized, and their morphologies were characterized by SEM,TEM and XRD patterns. By assembly of the synthesized nanomaterials, poly(dimethyldiallylammonium chloride) (PDDA), Au nanoparticles (AuNPs) and multi-wall carbon nanotubes (MCNTs) on the surface of GCE electrode, three kinds of nano-bionic interfaces, PDDA/Fe@Fe2O3-AuNPs/PDDA/GCE, PDDA/Fe@Fe2O3-MCNTs/PDDA /GCE and PDDA/nanoCu2O-AuNPs/PDDA/GCE, were constructed and the properties of them were studied by UV-vis spectroscopy. The DNA damage on these interfaces during the course of the cathodic treatment were studied by CV and DPV methods using Ru(NH3)63+ and Co(phen)33+ as electrochemical probes. The results showed that the DNA damage mainly happened during the course of the cathodic treatment. When these interfaces were treated by a cathodic process, the Fenton or like-Fenton reaction happened in interfaces and the reactive oxygen species (ROS) were produced. The ROS attacked and caused DNA damage in situ. The DNA damage courses in interface were just like the pathways of the heavy metal induced-DNA damage in vivo. Therefore, these biosensors can be used to mimic heavy metal gene toxicity pathways in vivo and can be used as powerful tools for screening the gene toxicity of chemicals.(2) By electrochemical polymerization, covalent combination, adsorption and casting methods, the polythionine (PTn), polytyrosine (PTyr), AuNPs and nanozirconia-polyaniline composite(nanoZrO2-PAN) were modified on the surface of GCE electrode and two biointerfaces, AuNPs/PTn/GCE and nanoZrO2-PAN/PTyr/GCE, were constructed. The properties of these two biointerfaces and the immobilization and hybridization of DNA on these surfaces were studied by CV, DPV and EIS. These two biointerfaces can be applied to detect the phosphinothricin acetyltransferase (PAT) gene sequences by a label-free EIS method. On the ss-DNA/AuNPs/PTn/GCE and ss-DNA/nanoZrO2-PAN/PTyr/GCE, the dynamic detection range of the PAT gene sequences were 1.0×10-10 1.0×10-6 mol/L and 1.0×10-13 1.0×10-6 mol/L, respectively, and the detection limit were 3.2×10-11 mol/L and 2.68×10-14 mol/L (S/N = 3), respectively. The ss-DNA/AuNPs/PTn/GCE was further used to detect the PCR amplification sample of terminator of nopaline synthase (NOS) from a kind of transgenic modified bean with satisfactory results. Compared with the biosensors constructed by ZrO2 normal materials, the biosensor composed by nanoZrO2-PAN has wider linear range and lower detection limit.(3) The Au-Pt alloy nanoparticles (Au-PtNPs) were synthesized by electrochemical deposition on the surface of the GCE electrode modified with the composite of polyaniline nanotubes (nanoPAN) and chitosan (CS). Then horseradish peroxidase (HRP) was immobilized on the surface of Au-PtNPs/nanoPAN/CS and the direct chemistry of HRP was obtained on this surface, based on which a novel H2O2 biosensor was constructed. The membrane properties of Au-PtNPs/nanoPAN/CS were studied with CV and EIS. Under the optimal conditions, the amperometric response of H2O2 on this biosensor was investigated by adding aliquots of H2O2 to a continuous stirring phosphate buffer solution. The biosensor displayed a fast response time (< 2 s) and broad linear response to H2O2 in the range from 1.0 to 2200μmol/L with a relatively low detection limit of 0.5μmol/L at 3 times the background noise. Moreover, the biosensor can be applied in practical analysis and exhibited high sensitivity, good reproducibility, and long-term stability.(4) The electrochemical behaviors of lincomycin on Au-PtNPs/nanoPAN/CS/GCE and amikacin on nanoPAN/CS/GCE were studied, respectively, and the electrochemical methods for detection of these two antibiotics were set up. The dynamic detection ranges of lincomycin and amikacin were 3.0 mg/L 100.0 mg/L and 10.0 mg/L 80.0 mg/L, and the detection limits were 8.0 mg/L and 1.0 mg/L (S/N = 3), respectively. Some electrochemical parameters involved in the redox reaction of lincomycin, such as parameter of kinetic nα, standard rate constant ks and the number of H+, were also calculated. Both of the methods can be used in practice.
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