| Organic-inorganic layered perovskite materials have special structure, which combine the useful chraracters of organic and inorganic compounds in a specific way. The templates of inorganic layers are octahedral metal halide [MX4]-. Organic cations interspersed between the inorganic layers. The properties of this materials can be designed and controlled. This materials can be used as particular properties and molecule device. It shows that they have great potential application in microelectronics, optics, electrochemical and biological fields.In this paper, organic-inorganic layered perovskite hybrids were synthesized in the air with phenosafranine, Neutral red and so on as organic sheets, and Fe(CN)63- as inorganic sheets. The morphology and microstructure of hybrid were characterized by scan electron microscopy (SEM) and X-ray diffractometry (XRD). Molecular formula was confirmed by fourier transform infrared spectroscopy (FTIR) and elemental analyzer (EA).When the reaction molecule ratio of phenosafranine and potassium Ferricyanide was 3:4, the results with molecule of (C18H15N4)3/4[Fe(CN)6] was typical layered perovskite structure. The (C18H15N4)3/4[Fe(CN)6] sample is composed of some regularly the scales closely stacked form flake five-sides that each side is 2-3μm, with different thickness and each layer is around 100-200 nm. The proportional of Neutral red and potassium Ferricyanide 3:4, the results show that the (NR)3/4[Fe(CN)6] was not particularly obvious layered characteristics. The hybrid sample showed that the appearance is not rule, orientation is poorer, layer is loose and the grain size is 20μm. Choosing other organic, molecular structure of the synthesized hybrid was not clear.Electrochemical performances of electrode modified by hybrid (C18H15N4)3/4[Fe(CN)6] was investigated with cyclic voltammetry. The electrode show good electrical catalysis to hydroquinone and DNA. It can be used to further quantitative detection.In pH 5.0 phosphate buffer solution, the electrochemical characteristic of the organic-inorganic layered perovskite hybrid modified electrode was studied. Compared with hydroquinone on carbon paste electrode (CPE), there are two reduction peaks on CPE, only one reduction peak on modified electrode. Using differential pulse voltammetry from -400 to 1000 mV potential range, the modified electrode were scanned. The reduction peak (Ep = -240.2 mV) current of modified electrode was linearly related to the concentration of hydroquinone between 1.0×10-6 to 1.0×10-3 mol/L, with a correlation coefficient of 0.995 1. The detection limit was 4.73×10-7 mol/L. For 5 parallel measurement of 1.0×10-5 mol/L hydroquinone, the relative standard deviation was found to be 1.8%. Other phenols were verified not interfering with the response of hydroquinone. The preparation of the electrode is simple and it has a good stability and reproducibility. The mean recovery of hydroquinone in the simulated water sample was 102%.DNA were successfully fixed on modified electrodes. And modified electrode immobilized ssDNA can be utilized to monitor the DNA hybridization and detect complementary ssDNA. Using square-wave voltammetry from -1000 to 2000 mV potential range, the modified electrode were scanned. Hybridization time is 20 min and the temperature is 4℃in pH 7.0 tris buffer solution. There is hybridization peak (Ep = 309.7 mV) on SWV curve using modified electrode immobilized ssDNA in the complementary ssDNA solution. A linear relationship between the peak current and the complementary ssDNA concentration in solution, the detection limit is 2.25×10-7 g/mL. For 5 continuous measurement of 1.0×10-5 g/mL ssDNA, the relative standard deviation was found to be 1.5%.The DNA biosensor exhibits a good reproducibility and stability. |
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