Preparation of surface molecular imprinting fluorescent sensor based on magnetic porous silica for sensitive and...

A magnetic fluorescent molecularly imprinted sensor was successfully prepared and implemented to determine catechol (CT). Fe₃O₄ nanoparticles were synthesized by the solvothermal technique and mesoporous Fe₃O₄@SiO₂@mSiO₂ imprinted carriers were prepared by coating nonporous and mesoporous SiO₂ shells on the surface of the Fe₃O₄ subsequently. The magnetic surface molecularly imprinted fluorescent sensor was created after the magnetic mesoporous carriers were modified with γ-methacryloxyl propyl trimethoxy silane to introduce double bonds on the surface of the carries and the polymerization was carried out in the presence of CT and fluorescent monomers. The magnetic mesoporous carriers were modified with γ-methacryloxyl propyl trimethoxy silane and double bonds were introduced on the surface of the carriers. After CT binding with the molecularly imprinted polymers (MIPs), the fluorescent intensity of the molecularly imprinted polymers (E_x = 400 nm, E_m = 523 nm) increased significantly. The fluorescent intensity ratio (F/F₀) of the sensor demonstrated a favorable linear correlation with the concentration of CT between 5 and 50 μM with a detection limit of 0.025 μM. Furthermore, the sensor was successfully applied to determine CT in actual samples with recoveries of 96.4-105% and relative standard deviations were lower than 3.5%. The results indicated that the research of our present work provided an efficient approach for swiftly and accurately determining organic pollutant in water.