Construction And Research Of Electrochemical Biosensor Based On Three Kinds Of Metal-organic Frameworks Compounds

MOFs are well-known crystalline inorganic-organic hybrid materials, in which metal clusters and organic ligands are connected in space in order to form three-dimensional ordered frameworks. Nowadays, the MOFs have attracted considerable attention due to its large surface area, high pore volume and high chemical stability. The outstanding properties of MOFs make them interesting for the application in gas storage, separation, catalysis, drug delivery, and sensing. This paper discusses its electrochemical properties; And successfully combines metal organic framework materials with enzyme, and its catalytic performance is discussed.1. A novel and simple hydrogen peroxide sensor based on metal(Cu(Ⅱ)、Ni(Ⅱ)、Co(Ⅱ)) coordination polymer with 4,4’-Bipyridine on carbon paste electrode(CPE) was constructed. The morphology and composition of the three frameworks materials(Cu-BPD, Co-BPD, Ni-BPD) were observed by UV-visible spectroscopy(UV-vis), Fourier transform infrared spectroscopy(FT-IR) and Scanning electron microscopy(SEM). The electrochemical performances of the modified electrodes had been studied by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS), respectively. Under the optimal conditions, the as-prepared Cu-BPD/CPE exhibited a good negatively response performance to hydrogen peroxide with a linear range from 2 n M to 2 m M with a detection limit of 0.7 n M(S/N=3). The resulted biosensor exhibited wide linear range and low detection limit.2. A novel nanoparticle of a metalloporphyrin metal-organic framework consisting of [5,10,15,20-(4-carboxyphenyl)porphyrin]Co(III)(Co TCPP) struts bound by linear trinuclear Co(II)-carboxylate clusters has been prepared solvothermally. And Cytochrome c was immobilized covalently onto Co TCPP nanoparticles with ionic liquid(IL) composite films diped on carbon paste electrode(IL/Cyt c/Co TCPP-CPE). The novel nanoparticle of a metalloporphyrin Co TCPP and The IL/Cyt c/Co TCPP substrate surfaces were characterized by transmission electron microscopy(TEM), Scanning electron microscopy(SEM), X-ray diffraction(XRD), Atomic Force Microscope(AFM) and UV-vis spectra(UV-vis) and Fourier transform infra-red spectroscopy(FT-IR). The properties of electrochemical sensor were discussed by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS) techniques. The IL/Cyt c/Co TCPP-CPE displayed a pair of well-defined redox peaks(Ep,a at 0.224 V and Ep,c at 0.181 V) at p H 7.0 in phosphate buffer solution. The modified electrode showed a linear response after the addition of hydrogen peroxide(H2O2). The developed electrode sensor had an electron transfer rate constant(ks) of 4.76 s-1 with a detection limit of 0.8 μM. The results of this study suggested that the hybrid layers were well fabricated on the CPE surface and the developed IL/Cyt c/Co TCPP-CPE displayed an excellent electrocatalytic response for the detection of H2O2.3. A novel multi-function Metal-Organic Frameworks composite(Ag@Zn-TSA) which was synthesized as highly efficient immobilization matrixes of myoglobin(Mb)/glucose oxidase(GOx) for electrochemical biosensing. An enzyme biosensor based on the immobilization of Mb/GOx on Ag@Zn-TSA composite and ionic liquid(IL) modified carbon paste electrode(CPE) were fabricated successfully. The composition and morphology of Metal-Organic Frameworks composite and modified electrodes were investigated by Fourier transform infrared spectrometry(FT-IR), UV-visible spectroscopy(UV-vis), X-ray diffraction(XRD), Energy Dispersive Spectrometer(EDS) and Scanning electron microscopy(SEM). Furthermore, the properties of the electrochemical sensor were discussed by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS). The enzyme biosensor showed wide linear response to hydrogen peroxide(H2O2) in the range of 0.3 μM- 20 m M, nitrite(NO2-) for 1.25 μM- 133 m M, glucose for 2.0 μM- 1022 μM, with a detection limit of 0.15 μM for H2O2, nitrite(NO2-) for 0.5 μM, glucose for 0.8 μM, respectively. In addition, this work indicated that Ag@Zn-TSA held great potential for constructing biosensors.