Surface Plasmon Resonance Sensor Research Based On Multi-Monomers 17?-Estradiol Molecularly Imprinted Polymer

In this thesis,the surface plasmon resonance sensor of 17?-estradiol(E2)molecularly imprinted polymer(MIP)was prepared by multi-monomers and the detection of E2 was carried out.Through a series of experiments and investigations,two kinds of monomers were choose to prepare E2 MIP,and the structure of double-layer MIP was further optimized.The main results are as follows:1.In order to ensure that the MIP is not damaged in the aqueous phase,the thickness(the increased value of the resonance angle)of the outer layer molecularly imprinted film(MIF)was 1.5°,the initiator concentration of the outer layer MIF was 0.015 g/m L.Because the inner MIF mainly improves the recognition sites,the UV-Vis spectroscopy was used to characterize the interactions between different monomers and E2.Finally,the monomer compositions of the inner layer MIF were methacrylic acid(MAA)and hydroxyethyl methacrylate(HEMA).2.Characterization and preparation of inner MIF with different mole ratios of MAA and HEMA with E2 mixtures.The result showed that the MIF with multifunctional monomers have higher affinities than the MIF with monofunctional monomer for the same concentration of estradiol.And the best adsorption effect is when the molar ratio of methacrylic acid and hydroxyethyl methacrylate is 3:1.3.After adsorption 5 times the same concentration E2 in PBS(p H=7.4),the sensor chip still had good absorption properties to E2.Under the same conditions,the same concentration of E2 molecule and E2 analogs such as testosterone,estrone,progesterone in PBS(p H=7.4)were absorbed.Among them,the changes of reflectivity(?R)were 0.029,0.003,0.005 and 0.003.The sensor chip had a high adsorption performance to E2 and had almost unresponsive to the analogues.This indicated that the sensor chip had a very good repeatability and selectivity.4.Through the SEM and contact angle characterization of the chip surface,we can see that the hydrophilicity of the sensor chip has been significantly improved.Due to the addition of hydrophilic monomer,the sensor chip not only succeeded in detecting E2 in PBS(p H=7.4)that close to the human body p H value,but also the lowest measurement concentration is 2.5×10^-16 mol/L.The sensor chip also can detect the low concentration of E2 in tap water,in that the tap water as the background solution.In conclusion,the E2 MIP that was prepared by the multi-monomers not only has good a selectivity and repeatability,but also its detection sensitivity in aqueous phase is further improved,providing methods and ideas for the detection of other small molecules in the aqueous phase.