Fabrication And Properties Of One-dimensional Core-shell Nanomaterials Having Optimized Metal-enhanced Fluorescence Effect

Core-shell nanocomposites exhibit excellent physical and chemical properties due to their composition,size,and morphology.Physical and chemical properties could be greatly improved if these factors can be effectively controlled.Gold nanorods(GNRs),anisotropic rod-shaped plasma nanoparticles,have a series of unique optical characteristics such as adjustable size,large spectral range,and size-dependent optical response.GNR were widely used in the fields of biomedicine,analytical detection,and optical catalysis.Polydiacetylene(PDA)polymers was widely used as a variety of sensing materials due to its unique fluorescent recognition function.However,the further applications based on PDA polymers would be hindered due to their low fluorescence quantum yield.At first the ambient electromagnetic field distribution and ultraviolet-visible absorption spectrum of a single gold nanorod were simulated by the finite-difference time-domain(FDTD)method.The aspect ratios of gold nanorods and the core-shell spacing were predicted.The simulated results in this study appears to be not only consistent with the following experimental results but also the results reported in the literatures.Then the GNR@PDA,one-dimensional core-shell nanomaterial capable of enhancing PDA fluorescence,was prepared following the principle of metal enhanced fluorescence(MEF).At last the fluorescence intensity of the PDA was significantly improved by adjusting the aspect ratio of the gold nanorods and the distance between the PDA and the surface of the GNR simultaneously.The parameters of the optimized group were the core material gold nanorod aspect ratio of 2.3 and the silica shell thickness of 10 nm.The recognition function of the fluorescent PDA could be improved.