Papers by Keyword: Molecularly Imprinted Polymers

Abstract: In this study, a kind of homogeneous spherical molecularly imprinted polymers (MIPs) with high specific surface area was prepared, with ginsenoside Re (Re) as template molecule, methacrylic acid (MAA) as functional monomers, ethylglycol dimethacrylate (EGDMA) as crosslinker and poly (vinyl alcohol)-1788 (PVA-1788) as dispersant. The MIPs was characterized by field emission scanning electron microscopy (FESEM) and surface porosity detector, and competitive adsorption behavior of the MIPs was evaluated under different two-component adsorption conditions. The experimental results showed that MIPs had the regular mesopores structure, equilibrium adsorption isotherms of MIPs were in good agreement with Freundlich model under different adsorption conditions (single solute adsorption (SSA), simultaneously competitive adsorption (SCA) and preloaded competitive adsorption (PCA)). The concentration of template (Re) and competitors (Rg1) affect the results of competitive adsorption. Re has obvious priority in competitive adsorption, and this unbalanced competitive adsorption was the results of spatial selectivity and strong inter-molecule forces of MIPs toward Re. The analysis of competitive adsorption of molecularly imprinted materials is helpful to further study the recognition mechanism of molecularly imprinted adsorbent.

Abstract: β-Cyclodextrin shows good molecular recognition ability for its unique physical and chemical properties and suitable cavity structure. The selective recognition can be further improved if β-cyclodextrin combines with molecularly imprinted technique. In this paper, the novel β-cyclodextrin functional monomers were introduced. And the preparation and application of molecularly imprinted polymers based on β-cyclodextrin functional monomers were reviewed. The development trend of β-cyclodextrin molecularly imprinted polymers were also prospected.

Abstract: Molecularly imprinted polymers could selectively adsorb the target analytes from complex matrix. Chinese medicinal herbs had the characteristics of multi-component contents and complicated matrix. Molecularly imprinted polymers were very suitable for the selective extraction and purification of effective components in Chinese medicinal herbs. In this paper, the preparation methods of quercetin molecularly imprinted polymers and its applications in the separation and analysis of Chinese medicinal herbs were comprehensively reported. It would be a good reference for the selective separation and purification of quercetin in Chinese medicinal herbs.

Abstract: Molecular imprinting technology (MIT) is a developing technique with high recognition which is just like the recognition between enzymes and antibodies in the organism. Molecularly imprinted polymers (MIPs), synthetic materials obtained using the imprinting technology, have played a huge advantage and been used in many fields. Especially, MIPs have been applied to the extraction and separation of analytes as the selective adsorbent of solid-phase extraction (SPE), which is known as molecularly imprinted polymer solid-phase extraction (MISPE) in recent years. In the present review, the methodology of MIPs preparation and evaluation are explained. Moreover, recent great developments of SPE and MISPE are discussed, and the potential application of MISPE in extraction of traditional Chinese medicine (TCM) active ingredients are also presented briefly.

Abstract: A new molecularly imprinted polymers (Rhodamine B-KH-570/SiO_2,MIPS) with high performance for recognizing Rhodamine B was prepared by adopting the surface molecular imprinting technique with silica-gel modified by KH-570 as a carrier material, acrylamide as the functional monomer and N,N-methylene-bis-acrylamide (MBA) as the crosslinker.The static adsorption experiments indicated that MIPS had significantly higher adsorption capacity for Rhodamine B than its non-imprinted polymers (NIPS). Dynamic binding study showed that the MIPS had good site accessibility and mass transport for Rhodamine B.Scatchard analysis revealed that two classes of binding sites were formed in MIPS with dissociation constants of 0.086mol/L and 0.0076 mol/L, and the maximum apparent binding capacity was 96.00μmol/g and 50.07 μmol/g, respectively.The selectivity coefficients and separation factors of MIPS for Rhodamine B in relation to competition species Rhodamine123 were 131.51 and 3.86 respectively, which suggested that MIPS had high recognition selectivity and binding affinity for the template molecule Rhodamine B.

Abstract: Molecularly imprinted polymers (MIPs) are synthetic materials that can be the environmental protection extraction method in TCM research and industry. They can overcome the defects of traditional extract methods and environmental pollution. In our research, MIPs were prepared by precipitation polymerization with neuro-protective picroside I and ginsenoside Rb1 as the template molecule. Moreover, the morphology of MIPs was characterized by electron microscope scanning and the static adsorption capacity was measured by the Scatchard equation. Finally, MIPs were made into MIP-SPE columns to enrich the template molecule and its analogues comparing with C₁₈-SPE column and the results show that MIPs have good affinity and selectivity towards the Rb1 and Picroside I in SPE columns. This research may offer a more environmentally friendly method to extract active compounds in the traditional herbal.

Abstract: Molecularly imprinted polymer (MIP) has the characteristics of predetermination, specific recognition and practicability. It can eliminate the interference of complicated matrix. It has been widely used as selective adsorption material in sample preparation. Bisphenol A is a common endocrine disruptor in environment. Its toxic effects and analysis have attracted widespread concern. In this paper, the molecularly imprinted sample preparation techniques for bisphenol A were comprehensively reported, including molecularly imprinted microspheres extraction, molecularly imprinted solid phase extraction, molecularly imprinted solid phase microextraction, molecularly imprinted stir bar sorptive extraction and molecularly imprinted membrane extraction. Moreover, the trends of BPA-molecularly imprinted techniques are prospected.

Abstract: A novel extraction method based on environmental protection was founded through molecularly imprinted polymers (MIPs), overcoming the defects of traditional extraction methods, such as reagents consuming, complex operation and environmental pollution. MIPs were prepared by precipitation polymerization with picroside II or ginsenoside rg1 as the template molecule. The morphology of MIPs was characterized by scanning electron microscope and its static adsorption capacity was measured by the Scatchard equation. In addition, MIPs were filled in the solid phase extraction (SPE) column to separate and enrich the template molecule and its analogues, compared with C₁₈-SPE column. The results indicated that MIPs have high affinity toward the template molecules, which might offer a novel method for the extraction of active compounds in the traditional herbal medicine.

Abstract: A monolithic column of molecularly imprinted polymer was prepared by an in situ polymerization method with a new compound R, S 3-(4-Fluorophenyl) -2, 2-Dimethylcyclopane Carboxamide which has fluorin organic compound as the template. The molecular recognition capabilities of the prepared monolithic MIP were evaluated by separating the enantiomers. The characteristics of the column and the influences of mobile phases were studied. The results showed that the monolithic column has chiral recognition capability for the template and the enantiomers were baseline separated even in aqueous solution.

Abstract: Based on the unique electronic properties and high adsorption capacity of carbon nanotubes, as well as the specific recognition ability of molecularly imprinted polymers, a novel molecularly imprinted carbon nanotubes electrochemical sensor with high sensitivity and selectivity was developed for bisphenol A (BPA) determination in water. The sensor was fabricated by directly thermalpolymerising molecularly imprinted film on a multi-wall carbon nanotubes (MWNTs) modified glassy carbon electrode (GCE). The linear sweep voltammogram of BPA on this sensor exhibited a well defined anodic peak. Under optimum conditions, the oxidation peak currents were linear to the concentration of BPA in the range of 0.1 mg/L-10.0 mg/L with a correlation coefficient of 0.9987 and a detection limit of 24.2 μg/L (S/N = 3). The proposed electrode exhibited good sensitivity and selectivity, and provided operation and store stability for the determination of BPA. The experiment results indicated a good potential application of the modified sensor in the detection of BPA.