| With the development of science and technology,Nano-materials have been widely applied to various fields. In which the magnetic and gold nanorods nano-materials not only with the general nature of nano-materials, But also have their own unique magnetic or optical properties. Based on the special advantages of Above-mentioned nanomaterials. In this paper,we done aspects of a number of listed exploration and research both from the theoretical and experimental for these nano-materials. First of all , based on the analysis and research for preparation methods of these nano-materials, followed were further analyzed and researched for the pairs of magnetic nanoparticles and the gold nanorods in the environment detection.First, a single dispersion of magnetic nanoparticles (Fe3O4) were been prepared by chemical coprecipitation . The acrylic monomers were added to Fe3O4 solution, and then adding hydrogen peroxide as the initiator of acrylic acid (AA) for the polymerization on the surface of nano-particles to form Polyacrylic acid -coated magnetic nanoparticles (PAA@Fe3O4) core-shell structure , The corresponding experimental conditions were optimized, and the phase of the nano-particles, particle size, magnetic content, and surface functional groups were characterized. The results showed that the best prepared under experimental conditions, the PAA @ Fe3O4 nanoparticles havet he average size of 8±2 nm, the surface of carboxyl-rich and has a good crystallographic morphology, with superparamagnetic at the same time.Second, established a new method for direct detection of sodium dodecyl sulfate (SDS) based on the PAA@Fe3O4 nanoparticles. Because the characteristic peak of methylene blue (MB) and the ion association complex (MB-SDS) in aqueous solution overlap at 662 nm and thus difficult for SDS determination. It was found that PAA @ Fe3O4 can be combined with the MB in place of 590 nm produce the new absorption peak, On the one hand, due to a large extent achieved the separation the MB and SDS-MB ion-association complex characteristic absorption peak , can be directly used for SDS Determination in the water , the detection limit of SDS Determination was 0.12 mg / L, On the other hand, used the magnetic separation to further Exclude MB-PAA@Fe3O4 background interference, the detection limit of SDS Determination was 0.06 mg / L. Extraction and use of this law without a lot of toxic organic reagents. This method does not require extraction and use of a large number of toxic organic reagents.Third,in the basis of Seed growth method,A new method which based on situ growth of for preparation gold nanorods was Proposed.The method make the seed preparation, growth medium preparation and growth of gold nanorods get together with organic, simplifying the experimental steps. analyzed and researched the amount of Cetyltrimethylammonium bromide,auric chloride acid,Ascorbic acid,Silver nitrate Combine with UV-visible spectrophotometer. At the same time, Investigate The effects of reaction time, temperature and other conditions on preparation of gold nanorods. Experiment by adjusting the quantity of sodium borohydride to achieve controllable aspect ratio(vertical/ horizontal) of Gold Nanorods Under the optimal conditions. The gold nanorods were preparation by this method have a good uniformity and reproducibility.Fourth, established a new method for Hg2+ determination based on the gold nanorods, which use Hg0 and Au0 have a special physical and chemical Reaction , use the strong reduce agent to reduction Hg0 to Hg2+ which deposited at both ends of gold nanorods,to make it produce ablation effect. the longitudinal maximum absorption wavelength of gold nanorods have the effect of blue shift with Increase concentration of Hg2+ show by UV - visible absorption spectra. Hg2+ at 0.5 ~ 10μmol/L concentration range with good linearity, the detection limit of SDS Determination was 0.25μmol/L. The method was simple and with high selectivity.
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