Optical Coupling And Glucose Sensing Study On The Three-Dimensional Hydrogel Hybrid Plasmon Photonic Crystals

Photonic crystals regulate the light field by dielectric constant or lattice constant.The resonance effect of plasma and free electrons of metal nanostructures can also provide another means of adjusting the interaction between light and matter.If an electronically excited oscillating material is introduced on the basis of a photonic crystal,it may cause a richer light modulation synergy effect between the photonic crystal and the local resonance effect,and enrich the light for applications such as photocatalysis,energy,biochemical sensing,etc.Field regulation means.The effective study of three-dimensional colloidal crystal template preparation makes the three-dimensional synergy of photonic crystal and uniform plasmon resonance more meaningful,and may optimize the response sensitivity of the Bragg diffraction mechanism,making it more sensitive to biochemical sensing.Therefore,we prepared a three-dimensional Ag plasmon photonic crystal structure with geometrically controllable and periodic distribution of Ag nanoparticles by hydrogel-assisted dissociation method.The structural coupling characteristics were analyzed by electromagnetic simulation and experimental spectroscopy and morphology.The glucose plasmon photon crystal glucose sensor was prepared with glucose-responsive gel as the assistant.The effects of coupling effect on the sensitivity of biochemical sensors were analyzed by electromagnetic simulation and experimental sensing and sensitivity calculation.The specific content includes:(1)Glucose-assisted hydrogel assisted preparation of Ag plasmon photonic crystals.The Ag inverse opal was prepared by electrochemical deposition using colloidal crystal as template.The glucose sensitive element 3-acrylamidophenylboronic acid(APBA)gel and glucose molecularly imprinted 4-vinylbenzeneboronic acid(VPBA)hydrogel were used.Auxiliary,using constant pressure electrochemical polishing method to obtain three-dimensional periodic distribution of Ag nanoparticles under the aid of gel.The preparation of low-filling Ag inverse opal by electrochemical polishing has been studied to achieve the purpose of increasing transmittance and maintaining complete periodicity,thus ensuring the smooth progress of photopolymerization hydrogel.The controllability of the electrochemical polishing process is improved by the relationship between the reverse recovery current and the degree of structural dissociation and polishing time during electrochemical polishing.(2)Optical coupling characteristics of Ag plasmon photonic crystals.The expression of local plasmon resonance,the appearance of the reflection peak of Ag plasmon photonic crystal and the optical coupling characteristics of Ag plasmon photonic crystal were studied by experiments and simulations.The electric field distribution and absorption spectrum analysis under different frequency bands show that the local plasmon resonance produces broad-spectrum absorption in the near-infrared to near-ultraviolet bands due to the different curvature of the tetrahedral Ag nanoparticles.The main causes of the main peaks and sub-peaks of the structure reflection are the first-order photonic band gap and the second-order photonic band gap generated by Bragg diffraction by the energy band structure of different lattice constants,the electric field distribution and the spectral characteristics analysis under different light incident angles.Experimental and simulation studies of different lattice constants with different Ag filling heights and different periodic dimensions reflect that the reflection peaks in the local plasmon resonance band are reflected by photonic band gap and local plasmon resonance.The coupling effect is determined by the fact that the position of the reflection peak moves and is nonlinearly related to the periodic lattice constant.(3)Sensitivity of Ag plasmon photonic crystals prepared by glucose sensitive element APBA gel to glucose response.Glucose was detected by APBA gel-assisted Ag inverse opal.The sensitivity of the experimental and simulated sensitivity calculations verified that the sensitivity of the Bragg secondary diffraction peak and the surface plasmon valley are in the same order of magnitude.Glucose plasmonic photonic crystals prepared by APBA gel were used to detect glucose.The structure reflection spectrum was significantly red-shifted with the increase of glucose concentration to realize the detection of glucose.Experimental and simulation methods were used to study different lattice constant structures.The sensitivity of the first-order and second-order diffraction of the glucose in the detection of glucose was found to have the greatest increase in the Bragg-level diffraction sensitivity of 300 nm periodic structure and the maximum increase in the Bragg secondary diffraction sensitivity of 200 nm periodic structure when the measured glucose concentration was in the range of 5-100 mM.When the glucose concentration is measured in the range of 0.1 to 0.5 mM,the Bragg-order diffraction sensitivity of the 400 nm periodic structure is maximally increased.The Bragg secondary diffraction sensitivity of the periodic structures of 200 nm3 300 nm,and 400 nm is improved.