Efficient Preparation of Homogeneous Chromogenic Glucose-responsive Photonic Crystal Gels by Magnetic Assembly Method
To efficiently prepare glucose-responsive photonic crystal gels with homogeneous coloration is still a challenge.A glucose-responsive gel embedded with ordered one-dimensional photonic crystal chains is fabricated by curing the precur-sors under both magnetic field and UV light.The chemically stable 3-acrylamidophenylboronic acid(3-APBA)is selected as the glucose-responsive co-monomer,which is negatively charged after recognizing glucose and makes the gel swelling.However,poly(vinylpyrrolidone)-coated magnetic colloidal nanoparticles(Fe3O4@PVP MCNCs)are prepared by solvother-mal method and used as the magnetic assembly elements for the construction of the one-dimensional photonic crystal struc-ture.MCNCs suspended in dimethyl sulfoxide/ethylene glycol(DMSO/EG)mixed solvent reach equilibrium by both spatial repulsion of PVP shell polymer and magnetic attraction along the direction of applied magnetic field,rapidly arranging into one-dimensional chain-like structures;while in the direction perpendicular to the magnetic field,magnetic particles repel each other and maintain the independent chains.When the total monomer concentration is 2.5 mol/L,the feeding molar ratio of 3-APBA and crosslinker to monomers are respectively 20％and 0.2％,the resultant hydrogel has satisfactory glu-cose-responsive swelling properties.The effects of MCNCs size,concentration,magnetic field strength and environmental pH on the glucose-responsive performance are investigated systematically.The diffraction wavelength of the photonic crystal gels will be red-shifted with the increase of the particle size and concentration of the MCNCs,the decrease of the applied magnetic field strength,and the enhancement of the test environment alkalinity.The results show that the photonic crystal gel,prepared by polymerizing the precursor solution containing MCNCs concentration of 4 g/L and a particle size of 181 nm at a moderate magnetic field strength of 8 mT,has the optimal glucose-responsive performance.It is able to change from blue to orange in glucose solutions from 0 to 50 mmol/L with satisfactory reusability,reaching a diffraction wavelength migration of nearly 100 nm.The glucose-responsive photonic crystal gel based on one-dimensional magnetic assembly chains has the advantages of facile preparation process,homogeneous structural color as well as stable and reversible responsiveness,and therefore,it has potential applications in the field of visual detection of glucose.
magnetic assemblyphotonic crystalglucose responsehydrogelvisualization
万方数据
维普
