Preparation And Performance Of Geniposide Molecularly Imprinted Materials

Geniposide,the main ingredients of Eucommia ulmoides,is a water-soluble iridoid glucoside,and has a significant effect on the cardiovascular system,the central nervous system and digestive diseases.In addition,Geniposide also has roles of anti-inflammatory and soft tissue injury treatments.Geniposide not only can be used as drug,but also has been widely used in other areas,such as biological detection agents,plant growth agents.At present,the method of extraction and purification is usually adoped for the separation and enrichment of Geniposide.However,in above method,the separation process is complex,can not achieve the specific separation,the product has more impurities,and the separation efficiency is low.Molecularly imprinting is a general technique for the preparation of materials containing predetermined selectable recognition sites by simulating molecular recognition mechanism in the nature.The molecularly imprinted polymer(MIP)can be synthesized by copolymerization of functional monomers and crosslinking agents in the presence of a template.The magnetic molecular imprinted polymers(MMIPs)prepared by surface molecularly imprinting on magnetism particles have the advantages of both molecularly imprinted polymer and magnetic polymer microspheres,especially have good superparamagnetism and high selective adsorption.Geniposide magnetic molecularly imprinted nanofiber membranes(Geniposide-MMINFMs)prepared by electrospinning have both the specific adsorption capacity of the molecularly imprinted polymers(MIPs),and the large surface area and high porosity of electrospinning nanofibers.In this paper,we choose geniposide as the template molecule to prepare the MIPs,Geniposide-MMINFMs,Geniposide-MMIPs by adopting bulk polymerization and electrospinning technique.The molecularly imprinted materials can be used as adsorbents to rapidly separate,purify,enrich trace or trace geniposide from complex matrix samples and provide favorable conditions for improving the accuracy and sensitivity of their analytical assays.The main contents are as follows:The molecularly imprinted polymer with specific recognition of geniposide was prepared thought the method of bulk polymerization,adopting geniposide as the template molecule,α-methacrylic acid as the functional monomer,ethylene glycol dimethacrylate(EDMA)as the crosslinking agent,and azobisisobutyronitrile(AIBN)as the initiator.The properties of imprinted polymers were studied by FT-IR,scanning electron microscopy(SEM)and high performance liquid chromatography(HPLC).The results showed that the MIPs had more holes than non-imprinted polymers,and the polymers were more dispersed.By the high performance liquid chromatogram,it was visible that template molecules were easy to elute.Besides the materials can be reused.By using the method of bulk polymerization,adopting geniposide as template molecule,α-methacrylic acid as functional monomer,ethylene glycol dimethacrylate as crosslinking agent,azobisisobutyronitrile as initiator,and then adding Nickel ferrite nanoparticles,magnetic molecularly imprinted polymers with specific recognition of geniposide were prepared.The polymers were characterized by FT-IR,transmission electron microscopy(TEM),vibrating sample magnetometer(VSM)and thermogravimetric analyzer(TGA).The results showed that the surface of the magnetic carrier was covered by molecularly imprinted polymer thin layer.The adsorption performance of the magnetic imprinted polymer was studied by high performance liquid chromatography(HPLC).The magnetic molecularly imprinted polymer(MMIPs)had a high adsorption capacity of 5.93μg/mg for the template molecules,and under the same conditions,the saturated adsorption capacity of the MNIPs is only 1.70μg/mg,and the saturated adsorption capacity of the MMIPs is 3.49 times of the MNIPs.Magnetic molecularly imprinted polymer(MMIPs)was prepared through copolymerization of magnetic nano nickel ferrite,template geniposide,dimethacrylate ethylene(EDMA)and azobisisobutyronitrile initiator(AIBN).The MMIP was mixed with polyvinyl butyral(PVB)at a mass ratio of 1:10 to prepare a spinning solution.Eventually,a magnetic geniposide-imprinted nanofiber membrane(MMINFMs)was fabricated through electrospinning.Under the conditions of ambient temperature of 25 oC,relative humidity of 40%–50%,MMINFMs exhibited a good microscopic morphology by scanning electron microscopy(SEM).The average diameter of fibers is 500 nm.Thermogravimetric analysis showed that the MMINFMs retained the thermal stability of PVB.The adsorption capacity of the MMINFMs was 1.6 times higher than that of a typical non-imprinted membrane.