The Control Preparation Of Au/Pt Nanocomposites And The Research Of Near-infrared Catalytic Antibacterial Behavior

The research and application of photocatalytic properties of nanomaterials are currently made good progress in many fields.Due to the unique adjustable optical properties of localized surface plasmon resonance of gold nanomaterials,they become the preferred material for the enhancement of photocatalytic properties of nanomaterials and has been widely used in different areas,for example,the decomposition of hydrogen,carbon dioxide decomposition,biological sterilization,water purification and so on.In this paper,the preparation of Au/Pt nanocomposite is used the photothermal method,and studied the optical properties of the material.The absorption peak position of local surface plasmon resonance is modulated from visible to near infrared region.The photocatalytic properties of Au/Pt nanocomposite is successfully validated,and the escherichia coli(E.coli)are successfully killed because of its catalytic properties.The main contents of this thesis include:(1)The relatively uniform Au NRs are prepared by seed growth method,Au/Pt nanocomposite was synthesized by the photothermal method with gold nanorods as a template.They were characterized by the visible absorption spectra,transmission electron microscopy,TEM – mapping.Comparing with ordinary chemical synthesis method can found the photothermal method are more efficient for well crystalline Au/Pt nanocomposite,the surface plasma resonance absorption peak are adjust from 800 nm to 1100 nm range.(2)The photocatalytic properties of the Au/Pt nanocomposites is verified by two ways of photothermal theory and surface enhanced Raman scattering which are based on surface plasmon resonance.They are characterized by near infrared imager,FDTD simulation of the electric field.We found that the highest temperature of the well crystalline Au/Pt nanocomposite is less than 30°C within 10 min,while the highest temperature of gold nanorods can be reached to 50°C.Instead,When the Au/Pt nanocomposites are as basement,the surface enhanced Raman signal of labeled molecule is about four times than the gold nanorods as basement.(3)The DPBF are chosen as the detection of singlet oxygen to further confirmed that the Au/Pt nanocomposite with photocatalytic properties.The biological sterilization experiment was carried out by using the photocatalytic properties of the Au/Pt nanocomposite,and achieved a beautiful result.Before the sterilization experiments,we first finished the toxicity of nanomaterials and the influence of the laser light source experiment in order to eliminate the influence of other factors on the experimental results and theoretical.Then,we choose the 810 nm absorption wavelength of which was synthesized by the photothermal method with the 0.10 M concentration of H2PtCl6·6H2O.The excitation wavelength of excitation light source was 808 nm and the sterilization experiment was carried out in sterile conditions.Then changing the concentration of the nanomaterials,the bacteria was almost completely killed when the concentration of Au/Pt nanocomposite was about 300 mg/mL.They characterized by the flat figure of bacterial growth,survival columnar diagram and TEM mode.We clearly observed the interaction between bacteria and nanomaterials in the process of sterilization state changes in different times.