Preparation Of Molecularly Imprinted Microspheres Of Phenolic Estrogens And Its Application In Foods And Environments

Molecularly imprinting technology originated from “key theory” by Fischer and“antibody formation theory” by Pauling, which was a specific molecule recognitiontechnology similar with the interaction of enzyme–substrate and receptor–antibody in organism. More and more pollutants and hazardous substances haveentered into environment and food recently and posed a grave threat to human’shealth. Molecular imprinted polymers (MIPs) were prepared by molecularly printingtechnology with pollutant as the template molecule. MIPs can recognize and adsorbtarget pollutants effectively by reducing the interference of matrix, increasing theselectivity of template, improving the enrichment efficiency and removing thepollutant in samples directly. Several new functional monomers and polymerizationtechnologies were introduced and some newly MIPs were presented. Details were asfollows:One-pot magnetic MIPs by RAFT precipitation polymerization for fast andselective removal of17β-estradiol (17β-E2): preparation and application. Thepollution of phenolic estrogens have become a global environmental problem,17β-E2can cause negative physiological effect of animals and influence the normalfunction of liver, kidney and other organs of human being through bioaccumulationprocess at trace level. It’s very necessary to detect and remove trace levels of17β-E2in environment and food samples. A novel MIPs with regular spherical morphologyfor17β-E2were prepared by reversible addition fragmentation chain transfertechnology and surface imprinting technology, which have strong magnetism, highbinding capacity and good selectivity. This new material can separate17β-E2fastunder external magnetic field and exhibit good recovery rate of17β-E2when appliedin solid phase extraction of environment and food samples.Thermo sensitive porous MIPs for bisphenol A (BPA): design, preparation,characterization and application. BPA is one of the volume endocrine disruptorswidely used as raw material of plastics or resins, antioxidant and polymerizationinhibitor. About5%of BPA production is used in food packaging and it iscontinuously introduced into the aquatic environment by means of industrial, agricultural, and municipal effluents. Excessive BPA can interfere with naturalhormone systems and cause a wide array of health problems. A smartthermosensitive MIPs for BPA were prepared by porous polymer technology andstimulus response technology under optimized condition. The synergistic effect oftwo functional monomers improved the adsorption capacity and mass transfer rate,the experimental equilibrium absorption capacity of BPA was5.03mg/g with theimprinting factor was4.11and the recovery rate was94.83-98.47%when applied insolid phase extraction of seawater and yogurt samples. This smart material showedregular spherical, good stability, good repeatability, good reusability, environmentalfriendly and was very sensitive to temperature.Fluorescence sensor MIPs were prepared through the quantum dot andimprinted site, the polymerization was processed in the surface of ZnS/Mn quantumdot, the elution and rebinding of template will influence the exciting light’s effect toQDs. Hence, the fluorescence intensity of the MIPs can reflect the adsorptionamount of templates; Protein imprinted polymers were prepared by peptidefragments imprinting method, which can recognize and adsorb the whole proteinmolecule by the specific imprinting sites of peptide fragments. Meanwhile, theadvantages and drawbacks of elaborated molecularly imprinted polymers wereanalyzed and summarized, and the main research contents and trends of MIPs in thefuture were described.