The increasing application of pesticides for agricultural purposes involves serious risk to the environment and human health due to either exposure or through residues in food and drinking water. Since food safety is ...The increasing application of pesticides for agricultural purposes involves serious risk to the environment and human health due to either exposure or through residues in food and drinking water. Since food safety is of mandatory importance there is a growing interest on the development of selective, simple, rapid, cost-effective and reliable analytical methodologies in order to ensure that pesticides residues should not be found at levels above the established maximum pesticide residue limits (MRLs). In recent years, a new methodology based on the development of molecularly imprinting polymers (MIPs) allows not only pre-concentration and cleaning of the sample but also selective extraction of the target analyte, which is crucial, particularly when the sample is complex and impurities can interfere with quantification. The scope of this review is to provide a general overview on MIPs field, with emphasis on MIP preparation and its use as sorbents for solid-phase extraction. This paper will be focused on the review of the current state of the art in the use of MIPs as selective materials in molecularly imprinted solid-phase extraction (MISPE) for the analysis of pesticide residues from food matrices. A review of preparation and application of MIPs in food matrices, will also be discussed.展开更多
Surface molecularly imprinted polymers(SMIPs) for selective adsorption of ampicillin sodium were synthesized using surface molecular imprinting technique with silica gel as a support.The physical and morphological cha...Surface molecularly imprinted polymers(SMIPs) for selective adsorption of ampicillin sodium were synthesized using surface molecular imprinting technique with silica gel as a support.The physical and morphological characteristics of the polymers were investigated by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FT-IR),thermogravimetric analysis(TGA),elemental analysis and nitrogen adsorption–desorption test.The obtained results showed that the SMIPs displayed great adsorption capacity(13.5 μg/mg),high recognition ability(the imprinted factor is 3.2) and good binding kinetics for ampicillin sodium.Finally,as solid phase extraction adsorbents,the SMIPs coupled with HPLC method were validated and applied for the enrichment,purification and determination of ampicillin sodium in real milk and blood samples.The averages of spiked accuracy ranged from 92.1% to 107.6%.The relative standard deviations of intra- and inter-day precisions were less than 4.6%.This study provides a new and promising method for enriching,extracting and determining ampicillin sodium in complex biological samples.展开更多
For preparing the phenobarbital(PHN) molecularly imprinted polymers(MIPs) with higher adsorption and selectivity properties, we used the M062 X/6-31 g(d,p) method of density functional theory to predict the various pr...For preparing the phenobarbital(PHN) molecularly imprinted polymers(MIPs) with higher adsorption and selectivity properties, we used the M062 X/6-31 g(d,p) method of density functional theory to predict the various properties of PHN-MIPs. Here PHN is as the imprinted molecule and acrylamide(AM) as the functional monomer. The ethylene glycol dimethacrylate,trimethylolpropane trimethacrylate, divinyl benzene, and pentaerythritol trimethacrylate are as the cross-linking agents, respectively. The acetonitrile, chloroform, toluene, and tetrahydrofuran are used as the solvents, respectively. The configurations of the molecular imprinting self-assembly system for PHN and AM have been simulated to study their bonding sites, binding energy, amount of hydrogen bond, and interaction mechanism. The essence of imprinting interaction for PHN and AM has been revealed by the atomic in the molecule theory. Meanwhile, the analogues of PHN were used to discuss the selectivity property of the stable PHN-AM complex. The results show that the PHN interacts with AM through hydrogen bonds. When the imprinting molar ratio of PHN-AM is1:6 and the THF is as the solvent, the amount of their hydrogen bonds is the most, the binding energy is the lowest, and their configuration is the most stable. In comparison with the other cross-linking agents(EGDMA, TRIM, and DVB), the PETA is more suitable for PHN-MIPs. The selective property of PHN-MIP to PHN is excellent when PHN and DMBA exist at the same time.展开更多
In this work the enhanced molecularly imprinted optosensing material based on graphene oxide-quantum dots （ GO- QDs） was synthesized for highly selective and sensitive specific recognition of the target protein, bov...In this work the enhanced molecularly imprinted optosensing material based on graphene oxide-quantum dots （ GO- QDs） was synthesized for highly selective and sensitive specific recognition of the target protein, bovine serum albumin （BSA）. Here, GO was introduced to enhance the efficiency of mass-transfer in recognition of target protein. Molecularly imprinted polymer coated GO-QDs using BSA as template （BMIP-coated GO-QDs ） exhibited a fast mass-transfer speed, which could be ascribed to the high volume of efficient surface area and high target recognition efficiency of the synthesized nanoscale device. Under optimal conditions, it was found that the BSA as target protein could remarkably quench the relative fluorescence intensity of BMIP- coated GO-QDs linearly in a concentration-dependent manner that was best described by a Stern-Volmer equation. The Ksv （Stern- Volmer constant） for template BSA was much higher than bovine hemoglobin （BHb） and lysozyme （Lyz）, implying a highly selective recognition ability of the BMIP-coated GO-QDs to BSA. This enhanced fluorescent nanoscale device may provide opportunities to develop a system that is efficient and effective and has potential in the design of highly effective fluorescent receptor for recognition of target protein in Droteomics studies.展开更多
Molecularly imprinted polymers(MIPs) were prepared by the bulk polymerization using crystal violet as the template molecule, and the methacrylic acid and ethylene glycol dimetheacrylate as functional monomer and cross...Molecularly imprinted polymers(MIPs) were prepared by the bulk polymerization using crystal violet as the template molecule, and the methacrylic acid and ethylene glycol dimetheacrylate as functional monomer and cross-linker, respectively. Systematic investigations of synthetic conditions were conducted. The surface morphology and recognition mechanism of the obtained polymers were studied using scanning electron microscope and spectrophotometric analysis. MIPs showed high affinity to template molecule and were successfully applied as special solid-phase extraction sorbent for selective extraction of crystal violet from natural seawater. An off-line molecularly imprinted solid-phase extraction(MISPE) method followed by high-performance liquid chromatography with diodearray detection for the analysis of crystal violet was also established. MISPE columns have good recoveries for crystal violet standard solutions and good linearity was obtained over the concentration range of 0-200 μg L-1(R2 > 0.99). Finally, two natural seawater samples were investigated. The recoveries of spiked seawater on the MISPE columns were from 44.47% to 62.34%, the relative standard deviation(n=3) being in the range of 2.89%-5.96%.展开更多
Molecularly imprinted polymers using 2,4-dichlorophenoxyacetic acid (2,4-D) as templates were prepared by suspension polymerization in silicon oil. The polymer particles exhibited regular shape in the micro-scale rang...Molecularly imprinted polymers using 2,4-dichlorophenoxyacetic acid (2,4-D) as templates were prepared by suspension polymerization in silicon oil. The polymer particles exhibited regular shape in the micro-scale range. The adsorbing experiments indicated that the imprinted polymer particles possessed higher affinity to 2,4-D than the non-imprinted polymer particles.展开更多
In the last decades, the extensive use of chemical and biological materials has not only seen to an increased transport of environmental pollutants but also, it has interfered and compromised the pristine state of dif...In the last decades, the extensive use of chemical and biological materials has not only seen to an increased transport of environmental pollutants but also, it has interfered and compromised the pristine state of different environmental matrices with emphasis on waterbodies. This has stimulated studies to develop and adopt novel techniques which consider the removal of pollutants with premium on economic feasibility, simple instrumentation, and high performance. In the treatment of water, the removal of trace concentration organic compounds and other numerous polluted water effluents is difficult due to limited affinity of trace compound ions to ion exchange resins. Because of the selective nature;recognition properties;adsorption ability;high stability;and easier preparation of molecular imprints, they are considered attractive and suitable artificial receptors to be applied in analytical separations, drug delivery, and as chemical sensors. In this review, we touch on the fundamentals of molecularly imprinted technologies and underscore some recent advances made in the development of imprinted polymers that are compatible with water and how they can be used in the clean-up of pollutants. The paper finally presents a comprehensive report on some challenges and outlook in the use of MIPs as water treatment sorbent.展开更多
A fluorescent competitive assay for melamine was first developed utilizing dummy molecularly imprinted polymers(DMIPs) as artificial antibodies. This method is based on the competition between fluorescent substances a...A fluorescent competitive assay for melamine was first developed utilizing dummy molecularly imprinted polymers(DMIPs) as artificial antibodies. This method is based on the competition between fluorescent substances and the unlabeled analyte for binding sites in synthesized DMIPs and the decreased binding of fluorescent substances to DMIPs due to increased concentrations of melamine in the solutions. DMIPs for melamine were synthesized under a hot water bath in the presence of the initiator azobisisobutyronitrile(AIBN) using 2,4-diamino-6-methyl-1,3,5-triazine(DAMT) as a dummy template, methacrylic acid(MAA) as a functional monomer, and ethylene glycol dimethacrylate(EGDMA) as a crosslinking agent. The adsorption capacity and selectivity of DMIPs for melamine were evaluated by the isothermal adsorption curve and Scatchard analysis. The evaluation results showed that the synthesized DMIPs had specific recognition sites for melamine and the maximum adsorption amount was 1 066.33 μg g^(–1). Later, 5-(4,6-d ichlorotriazinyl) amino fluorescein(DTAF) with a triazine ring, which s lightly resembles m elamine, w as selected as the fluorescent substance. The fluorescent competitive assay using DMIPs as t he antibody mimics was finally established by selecting and optimizing the reaction solvents, DMIPs amount, DTAF concentration, and incubation time. The optimal detection system showed a linear response w ithin range of 0.05–40 mg L^(–1) and the limit of detection(LOD) was 1.23 μg L^(–1). It was successfully applied to the detection of melamine in spiked milk samples wi th satisfactory recoveries(71.9 to 86.3%). According to the comparative analysis, the result of optimized fluorescent competitive assay re vealed excellent agreement with the HPLC-MS/MS result for melamine.展开更多
Molecularly imprinted polymers(MIPs) were applied as molecular recognition elements to an electrochemical sensor for cinchonidine(CD).A kind of MIP was synthesized with cinchonidine as template,modified rosin(ethylene...Molecularly imprinted polymers(MIPs) were applied as molecular recognition elements to an electrochemical sensor for cinchonidine(CD).A kind of MIP was synthesized with cinchonidine as template,modified rosin(ethylene glycol maleic rosinate acrylate) containing the skeleton of phenanthrene rings as cross-linker and methylacrylic acid as functional monomer.MIP membrane was prepared on a glassy carbon electrode for the determination of CD via free radical polymerization method.Electrochemical impedance spectroscopy(EIS) and cyclic voltammetry(CV) were used to characterize the membrane electrochemical behavior in electrode fabrication process.The experimental conditions were discussed.Under optimum conditions,it was found that the response of peak currents was linear to the concentration of CD in a range of 0.013―2.26 mmol/L.The detection limit for CD is 1 μmol/L,the relative standard deviation for 100 μmol/L CD is 1.34% and the incubation time is 2 min.The sensor was applied to the determination of CD in urine samples with satisfactory results.展开更多
Surface molecularly imprinted polymers (SMIP) was prepared via the reversible addition-fragmentation chain transfer (RAFT) polymerization on the chloromethyl polystyrene resin (CPR) in the presence of the template D-p...Surface molecularly imprinted polymers (SMIP) was prepared via the reversible addition-fragmentation chain transfer (RAFT) polymerization on the chloromethyl polystyrene resin (CPR) in the presence of the template D-phenylalanine. The structure of SMIP was characterized by FTIR and SEM. The adsorption behavior of D-phenylalanine of SMIP was preliminarily investigated.展开更多
Novel uniform-sized magnetic molecularly imprinted polymers(MMIPs) were synthesized for selective recognition of active antitumor ingredients of kaempferol(KMF) and protoapigenone(PA) in Macrothelypteris torresiana(M....Novel uniform-sized magnetic molecularly imprinted polymers(MMIPs) were synthesized for selective recognition of active antitumor ingredients of kaempferol(KMF) and protoapigenone(PA) in Macrothelypteris torresiana(M. torresiana) by surface molecular imprinting technique in this study. Super paramagnetic core-shell nanoparticles(γ-MPS-SiO 2@Fe3O4) were used as seeds, KMF as template molecule, acrylamide(AM) as functional monomer, and N, N'-methylene bisacrylamide(BisA M) as cross-linker. The prepared MMIPs were characterized by X-ray diffraction(XRD), Fourier transform infrared spectrum(FTIR), transmission electron microscopy(TEM) and thermo-gravimetric analysis(TGA), respectively. The recognition capacity of MMIPs was 2.436 times of non-imprinted polymers. The adsorption results based on kinetics and isotherm analysis were in accordance with the pseudo-second-order model(R2=0.9980) and the Langmuir adsorption model(R2=0.9944). The value of E(6.742 k J/mol) calculated from the Dubinin-Radushkevich isotherm model suggested that the physical adsorption via hydrogen-bonding might be predominant. The Scatchard plot showed a single line(R2=0.9172) and demonstrated the homogeneous recognition sites on MMIPs for KMF. The magnetic solid phase extraction(MSPE) based on MMIPs as sorbent was established for fast and selective enrichment of KMF and its structural analogue PA from the crude extract of M. torresiana and then KMF and PA were detected by HPLC-UV. The established method showed good performance and satisfactory results for real sample analysis. It also showed the feasibility of MMIPs for selective recognition of active structural analogues from complex herbal extracts.展开更多
The non-covalent interaction between apigenin (API) and different functional monomers (α-methylacrylic acid (MAA), acrylamide (AM), 2-vinylpyridine (2-Vpy) and combined functional monomers (AM/2-Vpy)) was determined ...The non-covalent interaction between apigenin (API) and different functional monomers (α-methylacrylic acid (MAA), acrylamide (AM), 2-vinylpyridine (2-Vpy) and combined functional monomers (AM/2-Vpy)) was determined by UV spectrometry, and a series of apigenin molecularly imprinted polymers (API-MIPs) was synthesized with different functional monomers through molecular imprinting technology. The relationship between the non-covalent interaction of template/functional monomer and absorption of MIPs also was studied. The results showed that the order of the strength of the non-covalent interaction between API and different functional monomers in tetrahydrofuran (THF) is as follows: 2-Vpy> AM/2-Vpy>AM>MAA, which is positive correlation to the absorption capability of corresponding MIPs, and 2-Vpy is the optimum functional monomer among the used monomer for preparing API- MIPs.展开更多
A new molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization using diclofenac (DFC) as a template. Binding characteristics of the MIP particles were evaluated by equilibrium binding experi...A new molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization using diclofenac (DFC) as a template. Binding characteristics of the MIP particles were evaluated by equilibrium binding experiments. DFC-MIP aqueous suspension and non-imprinted polymer (NIP) suspension were exposed to monochromatic UV light (253.7 nm) from low-pressure mercury lamps. UV-visible spectrophotometry (especially absorbance at 276 nm) showed that the DFC inside MIP particles degraded completely. After DFC-MIP suspension exposure to UV light the particles were completely regenerated after washing with water at least six times. The regenerated MIP particles rebounded considerable amount of DFC (approximately 88% removal of 44 ppm DFC). The stability of DFC was examined in the presence of various concentrations of hydrochloric acid (0.025 to 125 mM). Experimental results showed that degradation of DFC was efficient, depending on the acid concentration as well as the treatment time. However, there was no re-binding of DFC by the MIP particles after HCl treatment (and DDW washing) when exposed to DFC for 24 hours.展开更多
Molecularly imprinted technology (MIT) has the characteristics of specificity and high selectivity, which is one of the most promising methodologies. Besides, the polymers are made using MIT as the functional material...Molecularly imprinted technology (MIT) has the characteristics of specificity and high selectivity, which is one of the most promising methodologies. Besides, the polymers are made using MIT as the functional material of solid-phase extraction and chromatographic fractionating and sensor, because of the characteristics of the high selectivity, the better stability and easy preparation. This review introduces the progress in the application of MIT and summarizes its application in the chemistry.展开更多
Molecularly imprinted polymers selective for L-aspartic acid (LAA) have been prepared using the carboxy-betaine polymer bearing zwitterionic centres along the backbone. LAA is well known to promote good me-tabolism, t...Molecularly imprinted polymers selective for L-aspartic acid (LAA) have been prepared using the carboxy-betaine polymer bearing zwitterionic centres along the backbone. LAA is well known to promote good me-tabolism, treat fatigue and depression along with its significance in accurate age estimation in the field of forensic science and is an important constituent of ‘aspartame’, the low calorie sweetener. In order to study the intermolecular interactions in the prepolymerization mixture between the monomer and the template (LAA)/non-template (DAA), a computational approach was developed. It was based on the binding energy of the complex between the template and functional monomer. The results demonstrate that electrostatic in-teractions primarily guide the imprinting protocol. The MIP was able to selectively and specifically take up LAA from aqueous solution, human blood serum and certain pharmaceutical samples quantitatively. Hence, a facile, specific and selective technique to detect the amino acid, LAA in the presence of various interfer-rants, in different kinds of matrices is presented.展开更多
A molecularly imprinted polymer (MIP), prepared around a cotinine template, has been synthesized. The feasibility of using the polymer for solid-phase extraction (SPE) of cotinine from biological samples has been inve...A molecularly imprinted polymer (MIP), prepared around a cotinine template, has been synthesized. The feasibility of using the polymer for solid-phase extraction (SPE) of cotinine from biological samples has been investigated. The results show that cotinine can be quantitatively retained and eluted from the polymer. Experiments with human urine samples indicate that clean target analyte is obtained for HPLC with UV detection using the protocol.展开更多
(S)-4-Phenyl-2-oxazolidinone imprinted polymers were prepared by using methacrylic acid (MAA) as the functional monomer, and divinylbenzene (DVB) as crosslinker. The factors, which influence the selectivity of the pol...(S)-4-Phenyl-2-oxazolidinone imprinted polymers were prepared by using methacrylic acid (MAA) as the functional monomer, and divinylbenzene (DVB) as crosslinker. The factors, which influence the selectivity of the polymers were explored. Effective separation was observed for racemic 4-phenyl-2-oxazolidinone in mobile phase of acetonitrile. The investigation of mobile phase suggested that the hydrogen bonds between template and functional monomer was a primary factor in chiral recognition, while the preparation of polymers implied that the π-π stacking interaction between template and crosslinker played a role in imprinting procedure.展开更多
This letter used the molecular imprinting technology to build up the microenvironment around co-monomer bemin to mimic the cytochrome P450 catalyzing the epoxidation of styrene.The results showed that the conversion r...This letter used the molecular imprinting technology to build up the microenvironment around co-monomer bemin to mimic the cytochrome P450 catalyzing the epoxidation of styrene.The results showed that the conversion rates of products were obviously enhanced by molecularly imprinted polymers,compared to free hemin solution,using three kinds of oxidants.The used axial ligand in polymers synthesis also improved the total conversion rates.展开更多
基金funding by Fundos FEDER through Programa Operacional Factores de Competitividade-COM-PETE and Fundos Nacionais through FCT-Fundacao para a Ciencia e a Tecnologia(Project PTDC/AGR-ALI/117544/2010).
文摘The increasing application of pesticides for agricultural purposes involves serious risk to the environment and human health due to either exposure or through residues in food and drinking water. Since food safety is of mandatory importance there is a growing interest on the development of selective, simple, rapid, cost-effective and reliable analytical methodologies in order to ensure that pesticides residues should not be found at levels above the established maximum pesticide residue limits (MRLs). In recent years, a new methodology based on the development of molecularly imprinting polymers (MIPs) allows not only pre-concentration and cleaning of the sample but also selective extraction of the target analyte, which is crucial, particularly when the sample is complex and impurities can interfere with quantification. The scope of this review is to provide a general overview on MIPs field, with emphasis on MIP preparation and its use as sorbents for solid-phase extraction. This paper will be focused on the review of the current state of the art in the use of MIPs as selective materials in molecularly imprinted solid-phase extraction (MISPE) for the analysis of pesticide residues from food matrices. A review of preparation and application of MIPs in food matrices, will also be discussed.
基金financially supported by the National Natural Science Foundation of China (Nos. 81573391 and 81173024)the National Key Projects of China (No. 812277802)
文摘Surface molecularly imprinted polymers(SMIPs) for selective adsorption of ampicillin sodium were synthesized using surface molecular imprinting technique with silica gel as a support.The physical and morphological characteristics of the polymers were investigated by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FT-IR),thermogravimetric analysis(TGA),elemental analysis and nitrogen adsorption–desorption test.The obtained results showed that the SMIPs displayed great adsorption capacity(13.5 μg/mg),high recognition ability(the imprinted factor is 3.2) and good binding kinetics for ampicillin sodium.Finally,as solid phase extraction adsorbents,the SMIPs coupled with HPLC method were validated and applied for the enrichment,purification and determination of ampicillin sodium in real milk and blood samples.The averages of spiked accuracy ranged from 92.1% to 107.6%.The relative standard deviations of intra- and inter-day precisions were less than 4.6%.This study provides a new and promising method for enriching,extracting and determining ampicillin sodium in complex biological samples.
基金supported by the Science and Technology Research Project for Education Department of Jilin Province(No.JJKH20170299KJ)the Science and Technology Development Project of Jilin Province(No.20170520145JH)
文摘For preparing the phenobarbital(PHN) molecularly imprinted polymers(MIPs) with higher adsorption and selectivity properties, we used the M062 X/6-31 g(d,p) method of density functional theory to predict the various properties of PHN-MIPs. Here PHN is as the imprinted molecule and acrylamide(AM) as the functional monomer. The ethylene glycol dimethacrylate,trimethylolpropane trimethacrylate, divinyl benzene, and pentaerythritol trimethacrylate are as the cross-linking agents, respectively. The acetonitrile, chloroform, toluene, and tetrahydrofuran are used as the solvents, respectively. The configurations of the molecular imprinting self-assembly system for PHN and AM have been simulated to study their bonding sites, binding energy, amount of hydrogen bond, and interaction mechanism. The essence of imprinting interaction for PHN and AM has been revealed by the atomic in the molecule theory. Meanwhile, the analogues of PHN were used to discuss the selectivity property of the stable PHN-AM complex. The results show that the PHN interacts with AM through hydrogen bonds. When the imprinting molar ratio of PHN-AM is1:6 and the THF is as the solvent, the amount of their hydrogen bonds is the most, the binding energy is the lowest, and their configuration is the most stable. In comparison with the other cross-linking agents(EGDMA, TRIM, and DVB), the PETA is more suitable for PHN-MIPs. The selective property of PHN-MIP to PHN is excellent when PHN and DMBA exist at the same time.
文摘In this work the enhanced molecularly imprinted optosensing material based on graphene oxide-quantum dots （ GO- QDs） was synthesized for highly selective and sensitive specific recognition of the target protein, bovine serum albumin （BSA）. Here, GO was introduced to enhance the efficiency of mass-transfer in recognition of target protein. Molecularly imprinted polymer coated GO-QDs using BSA as template （BMIP-coated GO-QDs ） exhibited a fast mass-transfer speed, which could be ascribed to the high volume of efficient surface area and high target recognition efficiency of the synthesized nanoscale device. Under optimal conditions, it was found that the BSA as target protein could remarkably quench the relative fluorescence intensity of BMIP- coated GO-QDs linearly in a concentration-dependent manner that was best described by a Stern-Volmer equation. The Ksv （Stern- Volmer constant） for template BSA was much higher than bovine hemoglobin （BHb） and lysozyme （Lyz）, implying a highly selective recognition ability of the BMIP-coated GO-QDs to BSA. This enhanced fluorescent nanoscale device may provide opportunities to develop a system that is efficient and effective and has potential in the design of highly effective fluorescent receptor for recognition of target protein in Droteomics studies.
基金supported by the Natural Science Foundation of China (41076065)the Major State Basic Research Development Program of China (973 Program) (2010CB428701)
文摘Molecularly imprinted polymers(MIPs) were prepared by the bulk polymerization using crystal violet as the template molecule, and the methacrylic acid and ethylene glycol dimetheacrylate as functional monomer and cross-linker, respectively. Systematic investigations of synthetic conditions were conducted. The surface morphology and recognition mechanism of the obtained polymers were studied using scanning electron microscope and spectrophotometric analysis. MIPs showed high affinity to template molecule and were successfully applied as special solid-phase extraction sorbent for selective extraction of crystal violet from natural seawater. An off-line molecularly imprinted solid-phase extraction(MISPE) method followed by high-performance liquid chromatography with diodearray detection for the analysis of crystal violet was also established. MISPE columns have good recoveries for crystal violet standard solutions and good linearity was obtained over the concentration range of 0-200 μg L-1(R2 > 0.99). Finally, two natural seawater samples were investigated. The recoveries of spiked seawater on the MISPE columns were from 44.47% to 62.34%, the relative standard deviation(n=3) being in the range of 2.89%-5.96%.
基金supported by the National Natural Science Foundation of China(No 20274052).
文摘Molecularly imprinted polymers using 2,4-dichlorophenoxyacetic acid (2,4-D) as templates were prepared by suspension polymerization in silicon oil. The polymer particles exhibited regular shape in the micro-scale range. The adsorbing experiments indicated that the imprinted polymer particles possessed higher affinity to 2,4-D than the non-imprinted polymer particles.
文摘In the last decades, the extensive use of chemical and biological materials has not only seen to an increased transport of environmental pollutants but also, it has interfered and compromised the pristine state of different environmental matrices with emphasis on waterbodies. This has stimulated studies to develop and adopt novel techniques which consider the removal of pollutants with premium on economic feasibility, simple instrumentation, and high performance. In the treatment of water, the removal of trace concentration organic compounds and other numerous polluted water effluents is difficult due to limited affinity of trace compound ions to ion exchange resins. Because of the selective nature;recognition properties;adsorption ability;high stability;and easier preparation of molecular imprints, they are considered attractive and suitable artificial receptors to be applied in analytical separations, drug delivery, and as chemical sensors. In this review, we touch on the fundamentals of molecularly imprinted technologies and underscore some recent advances made in the development of imprinted polymers that are compatible with water and how they can be used in the clean-up of pollutants. The paper finally presents a comprehensive report on some challenges and outlook in the use of MIPs as water treatment sorbent.
基金supported by the National Natural Science Foundation of China (31260620, 31471654)the Special Fund for Agro-scientific Research in the Public Interest of China (201203094)
文摘A fluorescent competitive assay for melamine was first developed utilizing dummy molecularly imprinted polymers(DMIPs) as artificial antibodies. This method is based on the competition between fluorescent substances and the unlabeled analyte for binding sites in synthesized DMIPs and the decreased binding of fluorescent substances to DMIPs due to increased concentrations of melamine in the solutions. DMIPs for melamine were synthesized under a hot water bath in the presence of the initiator azobisisobutyronitrile(AIBN) using 2,4-diamino-6-methyl-1,3,5-triazine(DAMT) as a dummy template, methacrylic acid(MAA) as a functional monomer, and ethylene glycol dimethacrylate(EGDMA) as a crosslinking agent. The adsorption capacity and selectivity of DMIPs for melamine were evaluated by the isothermal adsorption curve and Scatchard analysis. The evaluation results showed that the synthesized DMIPs had specific recognition sites for melamine and the maximum adsorption amount was 1 066.33 μg g^(–1). Later, 5-(4,6-d ichlorotriazinyl) amino fluorescein(DTAF) with a triazine ring, which s lightly resembles m elamine, w as selected as the fluorescent substance. The fluorescent competitive assay using DMIPs as t he antibody mimics was finally established by selecting and optimizing the reaction solvents, DMIPs amount, DTAF concentration, and incubation time. The optimal detection system showed a linear response w ithin range of 0.05–40 mg L^(–1) and the limit of detection(LOD) was 1.23 μg L^(–1). It was successfully applied to the detection of melamine in spiked milk samples wi th satisfactory recoveries(71.9 to 86.3%). According to the comparative analysis, the result of optimized fluorescent competitive assay re vealed excellent agreement with the HPLC-MS/MS result for melamine.
基金Supported by the National Nature Science Foundation of China(Nos.21065001 and 30960306)the Natural Science Foundation of Guangxi Province,China(Nos.0639025,0991084 and 0991001z)+2 种基金the Fund of Guangxi Key Laboratory of Chemistry and Engineering of Forest Products,China(No.GXFC08-06)the Project of Education Department of Guangxi Province,China(No.200812MS074)the Innovation Project of Guangxi University for Nationalities,China(No.gxun-chx2011086)
文摘Molecularly imprinted polymers(MIPs) were applied as molecular recognition elements to an electrochemical sensor for cinchonidine(CD).A kind of MIP was synthesized with cinchonidine as template,modified rosin(ethylene glycol maleic rosinate acrylate) containing the skeleton of phenanthrene rings as cross-linker and methylacrylic acid as functional monomer.MIP membrane was prepared on a glassy carbon electrode for the determination of CD via free radical polymerization method.Electrochemical impedance spectroscopy(EIS) and cyclic voltammetry(CV) were used to characterize the membrane electrochemical behavior in electrode fabrication process.The experimental conditions were discussed.Under optimum conditions,it was found that the response of peak currents was linear to the concentration of CD in a range of 0.013―2.26 mmol/L.The detection limit for CD is 1 μmol/L,the relative standard deviation for 100 μmol/L CD is 1.34% and the incubation time is 2 min.The sensor was applied to the determination of CD in urine samples with satisfactory results.
文摘Surface molecularly imprinted polymers (SMIP) was prepared via the reversible addition-fragmentation chain transfer (RAFT) polymerization on the chloromethyl polystyrene resin (CPR) in the presence of the template D-phenylalanine. The structure of SMIP was characterized by FTIR and SEM. The adsorption behavior of D-phenylalanine of SMIP was preliminarily investigated.
基金supported by grants from the National Natural Science Foundation of China(No.21105032)Doctoral Program Fund of Ministry of Education of China(No.20110142120031)
文摘Novel uniform-sized magnetic molecularly imprinted polymers(MMIPs) were synthesized for selective recognition of active antitumor ingredients of kaempferol(KMF) and protoapigenone(PA) in Macrothelypteris torresiana(M. torresiana) by surface molecular imprinting technique in this study. Super paramagnetic core-shell nanoparticles(γ-MPS-SiO 2@Fe3O4) were used as seeds, KMF as template molecule, acrylamide(AM) as functional monomer, and N, N'-methylene bisacrylamide(BisA M) as cross-linker. The prepared MMIPs were characterized by X-ray diffraction(XRD), Fourier transform infrared spectrum(FTIR), transmission electron microscopy(TEM) and thermo-gravimetric analysis(TGA), respectively. The recognition capacity of MMIPs was 2.436 times of non-imprinted polymers. The adsorption results based on kinetics and isotherm analysis were in accordance with the pseudo-second-order model(R2=0.9980) and the Langmuir adsorption model(R2=0.9944). The value of E(6.742 k J/mol) calculated from the Dubinin-Radushkevich isotherm model suggested that the physical adsorption via hydrogen-bonding might be predominant. The Scatchard plot showed a single line(R2=0.9172) and demonstrated the homogeneous recognition sites on MMIPs for KMF. The magnetic solid phase extraction(MSPE) based on MMIPs as sorbent was established for fast and selective enrichment of KMF and its structural analogue PA from the crude extract of M. torresiana and then KMF and PA were detected by HPLC-UV. The established method showed good performance and satisfactory results for real sample analysis. It also showed the feasibility of MMIPs for selective recognition of active structural analogues from complex herbal extracts.
基金Financial supports from Ningbo Science and Technology Bureau(No.2007C10061)Department of Education of Zhejiang Province(No.20070963)Science and Technology Department of Zhejiang Province of China(No. 2008R40G2070056) are gratefully acknowledged
基金National Natural Science Foundation of China (No. 20877036)Advanced Talent Foundation of Jiangsu University (No. 04JBG017).
文摘The non-covalent interaction between apigenin (API) and different functional monomers (α-methylacrylic acid (MAA), acrylamide (AM), 2-vinylpyridine (2-Vpy) and combined functional monomers (AM/2-Vpy)) was determined by UV spectrometry, and a series of apigenin molecularly imprinted polymers (API-MIPs) was synthesized with different functional monomers through molecular imprinting technology. The relationship between the non-covalent interaction of template/functional monomer and absorption of MIPs also was studied. The results showed that the order of the strength of the non-covalent interaction between API and different functional monomers in tetrahydrofuran (THF) is as follows: 2-Vpy> AM/2-Vpy>AM>MAA, which is positive correlation to the absorption capability of corresponding MIPs, and 2-Vpy is the optimum functional monomer among the used monomer for preparing API- MIPs.
文摘A new molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization using diclofenac (DFC) as a template. Binding characteristics of the MIP particles were evaluated by equilibrium binding experiments. DFC-MIP aqueous suspension and non-imprinted polymer (NIP) suspension were exposed to monochromatic UV light (253.7 nm) from low-pressure mercury lamps. UV-visible spectrophotometry (especially absorbance at 276 nm) showed that the DFC inside MIP particles degraded completely. After DFC-MIP suspension exposure to UV light the particles were completely regenerated after washing with water at least six times. The regenerated MIP particles rebounded considerable amount of DFC (approximately 88% removal of 44 ppm DFC). The stability of DFC was examined in the presence of various concentrations of hydrochloric acid (0.025 to 125 mM). Experimental results showed that degradation of DFC was efficient, depending on the acid concentration as well as the treatment time. However, there was no re-binding of DFC by the MIP particles after HCl treatment (and DDW washing) when exposed to DFC for 24 hours.
文摘Molecularly imprinted technology (MIT) has the characteristics of specificity and high selectivity, which is one of the most promising methodologies. Besides, the polymers are made using MIT as the functional material of solid-phase extraction and chromatographic fractionating and sensor, because of the characteristics of the high selectivity, the better stability and easy preparation. This review introduces the progress in the application of MIT and summarizes its application in the chemistry.
文摘Molecularly imprinted polymers selective for L-aspartic acid (LAA) have been prepared using the carboxy-betaine polymer bearing zwitterionic centres along the backbone. LAA is well known to promote good me-tabolism, treat fatigue and depression along with its significance in accurate age estimation in the field of forensic science and is an important constituent of ‘aspartame’, the low calorie sweetener. In order to study the intermolecular interactions in the prepolymerization mixture between the monomer and the template (LAA)/non-template (DAA), a computational approach was developed. It was based on the binding energy of the complex between the template and functional monomer. The results demonstrate that electrostatic in-teractions primarily guide the imprinting protocol. The MIP was able to selectively and specifically take up LAA from aqueous solution, human blood serum and certain pharmaceutical samples quantitatively. Hence, a facile, specific and selective technique to detect the amino acid, LAA in the presence of various interfer-rants, in different kinds of matrices is presented.
基金supported by the National Natural Science Foundation of China(No.20405013)the Scientific Foundation of State Tobacco Monopoly Administration of China(No.110200201017).
文摘A molecularly imprinted polymer (MIP), prepared around a cotinine template, has been synthesized. The feasibility of using the polymer for solid-phase extraction (SPE) of cotinine from biological samples has been investigated. The results show that cotinine can be quantitatively retained and eluted from the polymer. Experiments with human urine samples indicate that clean target analyte is obtained for HPLC with UV detection using the protocol.
基金financed by the National Natural Science Foundation of China(No.20202015).
文摘(S)-4-Phenyl-2-oxazolidinone imprinted polymers were prepared by using methacrylic acid (MAA) as the functional monomer, and divinylbenzene (DVB) as crosslinker. The factors, which influence the selectivity of the polymers were explored. Effective separation was observed for racemic 4-phenyl-2-oxazolidinone in mobile phase of acetonitrile. The investigation of mobile phase suggested that the hydrogen bonds between template and functional monomer was a primary factor in chiral recognition, while the preparation of polymers implied that the π-π stacking interaction between template and crosslinker played a role in imprinting procedure.
文摘This letter used the molecular imprinting technology to build up the microenvironment around co-monomer bemin to mimic the cytochrome P450 catalyzing the epoxidation of styrene.The results showed that the conversion rates of products were obviously enhanced by molecularly imprinted polymers,compared to free hemin solution,using three kinds of oxidants.The used axial ligand in polymers synthesis also improved the total conversion rates.
