| In today’s society, noble metals are increasingly rare; furthermore, the nanoparticles of the noble metals have its particular properties, namely the localized Surface Plasmon Resonance. This can enhanced the electric filed of the surface of the nanoparticles, so has higher energy. At the same time, we fabricated the nano-film by layer-by-layer assembly, this method is an efficient, time saving, and advantages of convenient operation, layers assembled application in many ways, began to apply in the textile field.Localized Surface Plasmon resonance(LSPR) was a result of the interaction of light and nanoparticles. When light wave oscillation in the electric field can affect these free electrons and cause the free electrons in reciprocating oscillation, and resonance occurs until the frequency of incident wavelength and the frequencies of the reciprocating vibration of free electrons of the metal particles at the same time. The applications are the Surface Metal-enhanced Raman, metal Surface Metal-enhanced Fluorescence, Redshift, and Textile dyeing. Fluorescence enhancement and Red-shifted are the focus of this paper. Fluorescence enhancement of this phenomenon can use in quantitative and qualitative detection of biological proteins, bacteria, cells, and so on. It can accurate response the concentration, morphology and distribution of substance. And the redshift takes the advantage of that nanoparticles are sensitive to refractive index, so it can be used in the detection of the surrounding environment of nanoparticles. This method is easy and convenient; we can quickly know the changes in the surrounding environment of the nanoparticle.Traditional methods of preparing Nano-particle film are vapor deposition and chemical deposition, but they requires precision instruments, complex operation and costly spend. Moreover, we cannot gain the uniform mono- nanoparticle film. Layer-by-layer Assembly method is applying here, it can acquire uniform mononanoparticle film quickly and easily. Dipping and spraying can both have the same result. When spraying, we control the air pressure to decide the distance of inter-nanoparticles. When dipping, we control the immersion time to decide the distance of inter-nanoparticles. But this paper is not considered the time to control the distance of inter-nanoparticles.(1) We synthesis uniform and stable 60 nm Ag nanoparticles solution by sodium citrated, measuring the Zeta potential and UV. Then we used layer-by-layer assembly method to produce polymer substrate prepared with positive charges, laying the foundation for the deposition of nanoparticles with negative charges on the quartz chip. After that, spraying the silver nanoparticles on polymer substrates on the Quart and gained the silver Nano-film with fluorescence enhancement effect. But we found that the fluorescence enhancement of mono-layer sliver film is not obvious. So we sprayed multi-layer sliver film, and then linked with proteins to gain multilayers of silver Nano-film with 4 times enhancement of the fluorescence.(2) We synthesis uniform and stable solution of 41 nm Au nanoparticles and 41 nm Au nanoparticles by sodium citrated, measure the Zeta potential and UV. Then we used layer-by-layer assembly method to produce polymer substrate prepared with positive charges, laying the foundation for the deposition of nanoparticles with negative charges on the quartz chip. After that, dipping the gold nanoparticles on polymer substrates on the Quart and gained the gold Nano-film with redshift effect. We found that 41 nm Au NPs film has a wider range of the ultraviolet absorption peak, the distance shift of the peak is smaller than the 71 nm Au NPs film. Thus, 71 nm Au NPs film has a better result of redshift by layer-by-layer assembly method. We also explore the relation of numbers of layers and redshift, and consider the outcome of the shift of the Absorption intensity. We believe the(PDDA/Au)*5 is the best one to apply to detection. |
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