Optical Properties And Ph Response Of Three-Dimensional Plasmonic Crystal Based On Nano-Ag-Hydrogel

Photonic crystal can be widely applied to biochemical sensing due to the effective of manipulation incident electromagnetic waves.However,because of the limitations of photonic crystals,it can not achieve precise control of weak signal.Metal plasmonic is a kind of surface wave,which can realize the amplification of the intensity of the electromagnetic wave at the specific incident frequency.We use the effect of metal plasmonic to produce a new kind of nanometer microstructure which has characteristics of photonic crystals can also stimulate the metal plasmonic,so can achieve a more accurate control of the weak incident electromagnetic waves,we call this special microstructure metal plasmonic crystal.Compared to One-dimensional and Two-dimensional metal plasmonicic crystals,the Three-dimensional structure has a more excellent optical performance,In this research,we use hydrogel to dissociate the three-dimensional continuous Ag nanostructures to prepare Ag plamonic crystal,and use electromagnetic simulation and experiment spectrum test to analyze the optical properties.Details are as follows:(1)Preparation of three-dimensional Ag plasmonic crystal.Three-dimensional Ag plasmonic crystal was prepared by using colloidal crystal as template and hydrogel as base.Using Multi-Potential Steps and the polish panneters set as 6V,0.02s,the Three-dimensionan continuous Ag-nanostructure will be dissociated after polishing 30-80 cycles,such we prepare the Three-dimensionan discontinuous Ag plasmonic crystal.The surface and cross SEM picture show that we turely prepared the Three-dimensionan discontinuous Ag plasmonic crystal.The study shows that the polishing current is intrinsically related to the degree of dissociation of the Ag plasmonic crystal,and the process of dissociation is realized by the change of the polishing current.So that the control of the polishing process is realized.(2)Research the optical properties of Three-dimensional Ag plasmonic crystal.For the study of crystal optical properties,mainly using electromagnetic simulation and experimental testing methods.The results show that when the particle size of the template changes from 220nm to 380nm,the reflection peak maked by Nano-Ag particle resonance is shifted from 500nm to 900nm and show a linear changes.The spectrum of the crystal with a partical size of 394nm at different polishing were simulated,when the polishing degree change from 0%to 21.8%,the reflection spectrum change from do not have clear peak to have obvious reflection peaks,the transmission degree change from 0%to 80%,so the optical performance of Three-dimensional structure of the discontinuous structure is more excellent than continuous structure of the crystal;Under same template particle size,same degree of polishing,when the refractive index of hydrogel filled in Ag plasmonic crystal increase 0.1,the reflection spectrum of the crystal red shift 60nm,so the Ag plasmonic crystal is very sensitive to the change of refractive index;We simulation the spectrum response of different template layers.,when the number of template layers changes from 4 to 6,the peaks formed by Fabry-Perot interference are regularly moved;The energy band diagram and electric field are obtained by electromagnetic simulation,the results show the spectrum respond of Bragg crystal diffraction and Fabry-Perot interference.(3)pH response sensor research.First,we filled pH-sensitive hydrogels into the Ag-plasmonic crystal,the pH sensing hydrogels exhibited different degrees of swelling at different pH values solution.The swelling of the hydrogels changed the original structure of the crystals,will also have a response in spectrum.In the experiment,when the pH value of the drop solution change from 8 to 12,the reflection peak of the crystal shifted from 490nm to 590nm.