| Mesoporous silica, with many good properties such as good stability, large surface area and a lot of Si-OH to be modified, has been used in medicine transportation, catalysis and electrochemistry sensor. Nano Au, with special size, has become hot topic in optics, electricity, sensor and biochemistry. The fluoescence sensor has become hot spot because it shows good sensitivity. Pyrene is choosed as fluoescence materials because of obvious emssion and excitation peak.We combine mesoporous silicon, nano materials and fluoescence together in the aim of developing electrochemical sensors with high sensitivity and stability. These sensors can detect biological molecule(DA, H2O2 and Fe3+) successfully. In this artical three aspects are contained and listed as follow:(1) A sensor based on Au/mesoporous silicon for detecting H2O2A H2O2 sensor was fabricated based on TEOS, CATB and sulfydryl silica using a grafting method.Thiol-functional organic-inorganic mesoporous silica were synthesized. By using of the chemical bond of Au-SH, the material of Au-thiol-silica was gained(Au-SH-M). The material was investigated by X-ray diffraction(XRD),scanning transmission electron microscopy(TEM), BET, FTIR and cyclic voltammetry(CV), and electrochemical impedance spectroscopy(EIS) were carried out to investigate the electrochemical properties of the modified electrode.The results indicated the material was successfully synthesised and the sensor showed good electronic property. The sensor exhibited good response towards H2O2.The effects of assemble time and p H on the response characteristics of the sensor were investigated. Under the optimal experimental conditions, the current was linear with the concentration of H2O2 in the range from 0.1 ~ 12 m M with a detection limit of 1.2×10-6M(S/N = 3) and a correlation coefficient of 0.9800.(2) Study on the sensor based on APBA/mesoporous silicon for detecting DAA dopamine electrochemical sensor was perpared as following: First using a grafting method to get organic-inorganic hybrid mesoporous silicon materials based on TEOS, CATB, APTES and 3-Aminophenylboronic acid(APBA). And then scanning transmission electron microscopy(TEM), X-ray diffraction(XRD) and BET were used to characterize the nano material. The electrochemical property of the modified electrode was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The result showed the material was successfully synthesised and the selectivity of the sensor was good. Under the experiment conditions the current increased linearly with the concentration of dopamine from 0.05 ~ 0.8 m M with a relative coefficient(R = 0.9700) with a detection limit 4.872 u M(S/N = 3).(3) A fluorescene probe based on pyrene for detection of Fe3+We successfully designed fluorescent probe based on pyrene aldehyde,using fluorescent pyrene aldehyde, L-proline, 2,4-pentanedione, 2-Amino-5-chlorothiazole hydrochloride as main materials. It showed the material was successfully synthesized by investigating 1HNMR,13 CNMR, FTIR. The fluorescence sensor was tested by fluorescence spectrophotometer and the result turn out that the target material and pyrene aldehyde showed different emission peak.When Fe3+ ion was detected by the target materia, the intensity of the emission peak significantly decreased while the peak position not changed.The experiment showed that the fluorescent probe exhibited a good response to Fe3+ ion. As a result the fluorescent sensor was selective to Fe3+. The detecting range of the sensor was 9.0×10-8 ~ 1.0×10-6 M and the bonding constant is 3.5×103. |
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