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...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 lag/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 anapicillin 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
High selective molecularly imprinted polymers (MIPs) for tetracycline have been prepared by precipitation polymerization. Effects of monomer and solvent, the ratio of monomer and template and the characterization of...High selective molecularly imprinted polymers (MIPs) for tetracycline have been prepared by precipitation polymerization. Effects of monomer and solvent, the ratio of monomer and template and the characterization of the polymer were investigated by frontal chromatography and selectivity experiment. The results clearly indicated that the polymer, which had the highest molecular recognition abilities for tetracycline antibiotics, had been received.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 ra...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
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 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
Novel uniform-sized magnetic molecularly imprinted polymers (MMIPs) were synthe- sized for selective recognition of active antitumor ingredients of kaempferol (KMF) and protoapi- genone (PA) in Macrothelypteris ...Novel uniform-sized magnetic molecularly imprinted polymers (MMIPs) were synthe- sized for selective recognition of active antitumor ingredients of kaempferol (KMF) and protoapi- genone (PA) in Macrothelypteris torresiana (M. torresiana) by surface molecular imprinting tech- nique in this study. Super paramagnetic core-sheU nanoparticles (γ-MPS-SiO2@Fe3O4) were used as seeds, KMF as template molecule, acrylamide (AM) as functional monomer, and N, N'-methylene bisacrylamide (BisAM) as cross-linker. The prepared MMIPs were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrum fiT/R), 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 kJ/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 feasi- bility of MMIPs for selective recognition of active structural analogues from complex herbal extracts.展开更多
Molecularly imprinted polymers(MIPs) were applied as molecular recognition elements to an electro- chemical sensor for cinchonidine(CD). A kind of MIP was synthesized with cinchonidine as template, modified ro- si...Molecularly imprinted polymers(MIPs) were applied as molecular recognition elements to an electro- chemical sensor for cinchonidine(CD). A kind of MIP was synthesized with cinchonidine as template, modified ro- sin(ethylene glycol maleic rosinate acrylate) containing the skeleton of phenanthrene rings as cross-linker and me- thylacrylic acid as functional monomer. MIP membrane was prepared on a glassy carbon electrode for the determina- tion of CD via free radical polymerization method. Electrochemical impedance spectroscopy(EIS) and cyclic vol- tammetry(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 cur- rents 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 templa...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
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
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 ...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 heroin solution, using three kinds of oxidants. The used axial ligand in polymers synthesis also improved the total conversion rates.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 ...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 t...(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 л-л stacking interaction between template and crosslinker played a role in imprinting procedure.展开更多
There is a strong correlation between bisphenol A(BPA)and the risks of endocrine disruption in humans.However,the mechanism behind this correlation is still unknown due to the challenge of accurately assessing BPA lev...There is a strong correlation between bisphenol A(BPA)and the risks of endocrine disruption in humans.However,the mechanism behind this correlation is still unknown due to the challenge of accurately assessing BPA levels in biological matrices.Herein,we demonstrate a molecularly imprinted polymer(MIP)modified impedimetric sensor treated with bovine serum albumin(BSA)not only reduces the impact of protein interference but also maintains both specificity and sensitivity for the precise analysis of BPA.The platinum disc electrode was coated with MIP via electrochemical polymerization of o-phenylenediamine(o-PD)in the presence of BPA as a template,and free sites were then blocked with 1%BSA.Electrochemical impedance spectroscopy(EIS)was utilized for the detection of BPA.The linear range for detection was between 1.0 pg/L and 10.0 ng/L,with a detection limit(LOD)of 0.28 pg/L.The sensor presented a good selectivity over structurally similar steroid hormones and BPA metabolites.To validate the performance of the proposed sensor in the presence of possible interfering proteins,it was used to quantify BPA in real samples without any prior treatment.These findings indicate that such an impedimetric sensor can be used to measure BPA in complex matrices.展开更多
Food safety is a worldwide concern and is directly related to human health.Therefore,convenient,effective,and economical methods and technologies for food safety analysis have been developed continuously.Magnetic mole...Food safety is a worldwide concern and is directly related to human health.Therefore,convenient,effective,and economical methods and technologies for food safety analysis have been developed continuously.Magnetic molecularly imprinted polymers(MMIPs)have gained extensive attention in recent years,as they have high selectivity,high adsorption capacity,and are easy to isolate from food samples.Recently,advanced strategies for the synthesis of MMIPs have been proposed to solve problems of template leakage and non-specific adsorption,and to increase the biocompatibility,adsorption rate,as well as adsorption capacity of the imprinted materials.In this review,we focus on new attempts at modification of magnetic core and MMIPs’surfaces,and the selection of template,functional monomer,cross-linker as well as porogen.Studies are summarized that used advanced MMIPs for the recognition and adsorption of pesticide residues,veterinary drug residues,mycotoxins,contaminants,and adulterations in foodstuffs over the last 5 years.Finally,some still existing challenges and future prospects to further promote MMIPs properties are also discussed.展开更多
The characterization of these molecularly imprinted polymers is essential to understanding their binding dynamics and structural properties. Through the analysis of the current research, it is found that there are ove...The characterization of these molecularly imprinted polymers is essential to understanding their binding dynamics and structural properties. Through the analysis of the current research, it is found that there are overlaps in the methods used by scholars. The Langmuir equation is frequently applied to model the adsorption isotherms of MIPs, providing critical insight into the capacity and affinity of the binding sites. Infrared Spectroscopy (IR) plays a crucial role in identifying the functional groups involved in the imprinting process and confirming the successful formation of specific binding sites. UV-visible spectrophotometry is employed to monitor the absorption characteristics of the polymers, offering data on the interactions between the template molecules and the polymer matrix. Transmission Electron Microscopy (TEM) provides detailed visualization of the internal structure of MIPs at the nanoscale, revealing the morphology and size of the imprinted cavities. Thermogravimetric Analysis (TGA) assesses the thermal stability and composition of the polymers, identifying decomposition patterns that are indicative of the material’s robustness under different conditions. Finally, the Laser Particle Size Analyzer is used to measure the size distribution of the polymer particles, which is critical for determining the uniformity and efficiency of the imprinting process. The six characterization methods discussed in this paper provide a comprehensive understanding of MIP, and it is hoped that in the future, more optimized design solutions will emerge and their applications in various fields will be enhanced.展开更多
Hydrophilic molecularly imprinted polymers(MIPs) were prepared using tetracycline as template,methacrylic acid as monomer and glycidilmethacrylate as pro-hydrophilic co-monomer.Compared with common MIPs,the imprinti...Hydrophilic molecularly imprinted polymers(MIPs) were prepared using tetracycline as template,methacrylic acid as monomer and glycidilmethacrylate as pro-hydrophilic co-monomer.Compared with common MIPs,the imprinting effect and adsorption amounts of hydrophilic MIPs for tetracycline(TC) were greatly improved in water media.Furthermore,the electrochemical sensor fabricated by modifying hydrophilic MIPs on glassy carbon electrode was developed for the determination of TC in foodstuff samples.展开更多
Antibiotic contamination of the water environment has attracted much attention from researchers because of their potential hazards to humans and ecosystems.In this study,a multi-template molecularly imprinted polymer(...Antibiotic contamination of the water environment has attracted much attention from researchers because of their potential hazards to humans and ecosystems.In this study,a multi-template molecularly imprinted polymer(MIP)modified mesoporous silica coated magnetic graphene oxide(MGO@MS@MIP)was prepared by the surface imprinting method via a sol-gel process and was used for the selective,efficient and simultaneous removal of tetracyclines(TCs),including doxycycline(DC),tetracycline(TC),chlorotetracycline(CTC)and oxytetracycline(OTC)from water.The synthesized MIP composite was characterized by Fourier transform infrared spectroscopy,transmission electron microscope and thermogravimetric analysis.The adsorption properties of MGO@MS@MIP for these TCs were characterized through adsorption kinetics,isotherms and selectivity tests.The MIP composite revealed larger adsorption quantities,excellent selectivity and rapid kinetics for these four tetracyclines.The adsorption process was spontaneous and endothermic and followed the Freundlich isotherm model and the pseudo-second-order kinetic model.The MGO@MS@MIP could specifically recognize DC,TC,CTC and OTC in the presence of some chemical analogs.In addition,the sorption capacity of the MIP composite did not decrease significantly after repeated application for at least five cycles.Thus,the prepared magnetic MIP composite has great potential to contribute to the effective separation and removal of tetracyclines from water.展开更多
Perfluorooctane sulfonate(PFOS),as a potential persistent organic pollutant,has been widely detected in water environments,and has become a great concern in recent years.PFOS is very stable and difficult to decompose ...Perfluorooctane sulfonate(PFOS),as a potential persistent organic pollutant,has been widely detected in water environments,and has become a great concern in recent years.PFOS is very stable and difficult to decompose using conventional techniques.Sorption may be an attractive method to remove it from water.In this study,the molecularly imprinted polymer(MIP)adsorbents were prepared through the polymerization of 4-vinylpyridine under different preparation conditions in order to remove perfluorooctane sulfonate(PFOS)from water.The MIP adsorbents using perfluorooctanoic acid(PFOA)as the template had good imprinting effects and could selectively remove PFOS from aqueous solution.The sorption behaviors including sorption kinetics,isotherms,and effect of pH,salt,and competitive anions were investigated.Experimental results showed that the sorption of PFOS on the MIP adsorbents was very fast,pHdependent,and highly selective.The achieved fast sorption equilibrium within 1 h was attributed to the surface sorption on the fine adsorbents.The sorption isotherms showed that the sorption selectivity of PFOS on the MIP adsorbents decreased at high PFOS concentrations,which may be due to the double-layer sorption and the formation of PFOS micelles on the sorbent surface.The sorption of PFOS on the MIP adsorbents was mainly dominated by the electrostatic interaction between the protonated vinylpyridine on the adsorbent surface and the anionic PFOS.The prepared MIP adsorbents can potentially be applied in water and wastewater treatment for selective removal of PFOS.展开更多
Molecularly imprinted polymers (MIPs) have great potential as adsorbents for selective adsorption and separation of nucleoside compounds,but effectively enhancing the affinity of recognition sites by adjusting the for...Molecularly imprinted polymers (MIPs) have great potential as adsorbents for selective adsorption and separation of nucleoside compounds,but effectively enhancing the affinity of recognition sites by adjusting the forces between template molecules and functional monomers remains an important challenge.In this work,a surface imprinting strategy was used to construct bowl-shaped molecularly imprinted composite sorbents (BHPN@MIPs) based on polydopamine (PDA) particles and have achieved selective separation and purification of 2'-deoxyadenosine (dA).Where by the base complementary pairing interaction of the combined template molecule d A and the pyrimidine functional monomer can enhance the preassembly force,and the hydrophilic bowl-shaped PDA can provide a larger storage space contact efficiency of d A in the test solution,causing the site utilization much higher and improving the kinetic adsorption performance.The equilibrium adsorption time and maximum adsorption capacity of60 min and 328.45μmol·g^(-1)were observed by static adsorption experiments,and the selectivity experimental results showed an imprinting factor IF of 1.30.After four adsorption–desorption cycles,the initial adsorption equilibrium adsorption capacity of BHPN@MIPs still retained 91.14%.By evaluating the selective adsorption of d A in spiked human serum solutions,BHPN@MIPs can be used to selectively enrich and analyze target d A in complex biological samples.展开更多
Sulfamethoxazole(SMX)is a sulfonamide antibiotic primarily used to treat urinary tract infections and used in veterinary and industrialized husbandry to treat diseases and food additives.Like other antibiotics,SMX is ...Sulfamethoxazole(SMX)is a sulfonamide antibiotic primarily used to treat urinary tract infections and used in veterinary and industrialized husbandry to treat diseases and food additives.Like other antibiotics,SMX is considered as a pollutant in water and food that threaten local life.This study developed a surface plasmon resonance(SPR)sensor chip that is fast,highly selective,and reusable,and requires no pretreatment for detecting SMX.As a receptor,SMX imprinted methacrylic acid-2-hydroxyethyl methacrylate-ethylene glycol dimethacrylate polymer[poly(MAA-HEMA-EGDMA)]was used.The surface of the gold SPR chips was coated with a drop-casting method.The nanofilm coated chips were characterized by scanning electron microscopy(SEM),atomic force microscopy(AFM),ellipsometer,contact angle measurement,and Fourier-transform infrared spectrometry(FTIR).Imprinting factor(IF)was calculated as:ΔR[MIP(molecularly imprinted polymers)]/ΔR[NIP(non-imprinted)]=12/3.5=3.4.Limit of detection(LOD)and limit of quantification(LOQ)values were calculated with 3 s/m and 10 s/m methods,and the results were found to be 0.0011μg/L for LOD 0.0034μg/L for LOQ.Adsorption studies on both standard SMX solution and commercial milk samples were applied.Also,we investigated the developed chip’s reusability,storability,and selectivity with amoxicillin and cefalexin.展开更多
A novel method to prepare surface plasmon resonance(SPR) sensor chips based on grafted imprinted polymer is explored. Benzophenone photografting system is used to grow molecularly imprinted polymer(MIP) films from...A novel method to prepare surface plasmon resonance(SPR) sensor chips based on grafted imprinted polymer is explored. Benzophenone photografting system is used to grow molecularly imprinted polymer(MIP) films from the modified surface of gold substrate.The surface morphology and thickness of MIP films were investigated by scanning electronic microscope(SEM).The adsorption properties of sensor chip were studied by SPR spectroscopy.The results demonstrate that nano-MIP films can be constructed on the surface of gold substrate with the good adsorption of template molecules.展开更多
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 lag/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 anapicillin 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.
文摘High selective molecularly imprinted polymers (MIPs) for tetracycline have been prepared by precipitation polymerization. Effects of monomer and solvent, the ratio of monomer and template and the characterization of the polymer were investigated by frontal chromatography and selectivity experiment. The results clearly indicated that the polymer, which had the highest molecular recognition abilities for tetracycline antibiotics, had been received.
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.
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 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 synthe- sized for selective recognition of active antitumor ingredients of kaempferol (KMF) and protoapi- genone (PA) in Macrothelypteris torresiana (M. torresiana) by surface molecular imprinting tech- nique in this study. Super paramagnetic core-sheU nanoparticles (γ-MPS-SiO2@Fe3O4) were used as seeds, KMF as template molecule, acrylamide (AM) as functional monomer, and N, N'-methylene bisacrylamide (BisAM) as cross-linker. The prepared MMIPs were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrum fiT/R), 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 kJ/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 feasi- bility of MMIPs for selective recognition of active structural analogues from complex herbal extracts.
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 electro- chemical sensor for cinchonidine(CD). A kind of MIP was synthesized with cinchonidine as template, modified ro- sin(ethylene glycol maleic rosinate acrylate) containing the skeleton of phenanthrene rings as cross-linker and me- thylacrylic acid as functional monomer. MIP membrane was prepared on a glassy carbon electrode for the determina- tion of CD via free radical polymerization method. Electrochemical impedance spectroscopy(EIS) and cyclic vol- tammetry(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 cur- rents 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.
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 heroin solution, using three kinds of oxidants. The used axial ligand in polymers synthesis also improved the total conversion rates.
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 л-л stacking interaction between template and crosslinker played a role in imprinting procedure.
基金supported by the Foundation of Liaoning Province Education Administration(LJKZ1145)the Natural Science Foundation of Liaoning Province(2022–NLTS–14–02)。
文摘There is a strong correlation between bisphenol A(BPA)and the risks of endocrine disruption in humans.However,the mechanism behind this correlation is still unknown due to the challenge of accurately assessing BPA levels in biological matrices.Herein,we demonstrate a molecularly imprinted polymer(MIP)modified impedimetric sensor treated with bovine serum albumin(BSA)not only reduces the impact of protein interference but also maintains both specificity and sensitivity for the precise analysis of BPA.The platinum disc electrode was coated with MIP via electrochemical polymerization of o-phenylenediamine(o-PD)in the presence of BPA as a template,and free sites were then blocked with 1%BSA.Electrochemical impedance spectroscopy(EIS)was utilized for the detection of BPA.The linear range for detection was between 1.0 pg/L and 10.0 ng/L,with a detection limit(LOD)of 0.28 pg/L.The sensor presented a good selectivity over structurally similar steroid hormones and BPA metabolites.To validate the performance of the proposed sensor in the presence of possible interfering proteins,it was used to quantify BPA in real samples without any prior treatment.These findings indicate that such an impedimetric sensor can be used to measure BPA in complex matrices.
基金This work was supported by the National Key Research and Development Programs of China(2022YFF1100900).
文摘Food safety is a worldwide concern and is directly related to human health.Therefore,convenient,effective,and economical methods and technologies for food safety analysis have been developed continuously.Magnetic molecularly imprinted polymers(MMIPs)have gained extensive attention in recent years,as they have high selectivity,high adsorption capacity,and are easy to isolate from food samples.Recently,advanced strategies for the synthesis of MMIPs have been proposed to solve problems of template leakage and non-specific adsorption,and to increase the biocompatibility,adsorption rate,as well as adsorption capacity of the imprinted materials.In this review,we focus on new attempts at modification of magnetic core and MMIPs’surfaces,and the selection of template,functional monomer,cross-linker as well as porogen.Studies are summarized that used advanced MMIPs for the recognition and adsorption of pesticide residues,veterinary drug residues,mycotoxins,contaminants,and adulterations in foodstuffs over the last 5 years.Finally,some still existing challenges and future prospects to further promote MMIPs properties are also discussed.
文摘The characterization of these molecularly imprinted polymers is essential to understanding their binding dynamics and structural properties. Through the analysis of the current research, it is found that there are overlaps in the methods used by scholars. The Langmuir equation is frequently applied to model the adsorption isotherms of MIPs, providing critical insight into the capacity and affinity of the binding sites. Infrared Spectroscopy (IR) plays a crucial role in identifying the functional groups involved in the imprinting process and confirming the successful formation of specific binding sites. UV-visible spectrophotometry is employed to monitor the absorption characteristics of the polymers, offering data on the interactions between the template molecules and the polymer matrix. Transmission Electron Microscopy (TEM) provides detailed visualization of the internal structure of MIPs at the nanoscale, revealing the morphology and size of the imprinted cavities. Thermogravimetric Analysis (TGA) assesses the thermal stability and composition of the polymers, identifying decomposition patterns that are indicative of the material’s robustness under different conditions. Finally, the Laser Particle Size Analyzer is used to measure the size distribution of the polymer particles, which is critical for determining the uniformity and efficiency of the imprinting process. The six characterization methods discussed in this paper provide a comprehensive understanding of MIP, and it is hoped that in the future, more optimized design solutions will emerge and their applications in various fields will be enhanced.
基金financed by the Entry-Exit Inspection and Quarantine Bureau of PRC(Nos.2006IK152,2009IK 130 and 200910085)
文摘Hydrophilic molecularly imprinted polymers(MIPs) were prepared using tetracycline as template,methacrylic acid as monomer and glycidilmethacrylate as pro-hydrophilic co-monomer.Compared with common MIPs,the imprinting effect and adsorption amounts of hydrophilic MIPs for tetracycline(TC) were greatly improved in water media.Furthermore,the electrochemical sensor fabricated by modifying hydrophilic MIPs on glassy carbon electrode was developed for the determination of TC in foodstuff samples.
基金the Science and Technology Planning Project of Guangzhou,China(No.201803030040)the National Natural Science Foundation of China(Grant No.41272262)the Major Projects(Natural Science)of Education Department of Guangdong Province,China(261555101).
文摘Antibiotic contamination of the water environment has attracted much attention from researchers because of their potential hazards to humans and ecosystems.In this study,a multi-template molecularly imprinted polymer(MIP)modified mesoporous silica coated magnetic graphene oxide(MGO@MS@MIP)was prepared by the surface imprinting method via a sol-gel process and was used for the selective,efficient and simultaneous removal of tetracyclines(TCs),including doxycycline(DC),tetracycline(TC),chlorotetracycline(CTC)and oxytetracycline(OTC)from water.The synthesized MIP composite was characterized by Fourier transform infrared spectroscopy,transmission electron microscope and thermogravimetric analysis.The adsorption properties of MGO@MS@MIP for these TCs were characterized through adsorption kinetics,isotherms and selectivity tests.The MIP composite revealed larger adsorption quantities,excellent selectivity and rapid kinetics for these four tetracyclines.The adsorption process was spontaneous and endothermic and followed the Freundlich isotherm model and the pseudo-second-order kinetic model.The MGO@MS@MIP could specifically recognize DC,TC,CTC and OTC in the presence of some chemical analogs.In addition,the sorption capacity of the MIP composite did not decrease significantly after repeated application for at least five cycles.Thus,the prepared magnetic MIP composite has great potential to contribute to the effective separation and removal of tetracyclines from water.
基金This work was supported by the National Natural Science Foundation of China(Grant No.50608045)the special fund of State Key Joint Laboratory of Environment Simulation and Pollution(Grant No.08Z04ESPCT)the National Outstanding Youth Foundation of China(Grant No.50625823).
文摘Perfluorooctane sulfonate(PFOS),as a potential persistent organic pollutant,has been widely detected in water environments,and has become a great concern in recent years.PFOS is very stable and difficult to decompose using conventional techniques.Sorption may be an attractive method to remove it from water.In this study,the molecularly imprinted polymer(MIP)adsorbents were prepared through the polymerization of 4-vinylpyridine under different preparation conditions in order to remove perfluorooctane sulfonate(PFOS)from water.The MIP adsorbents using perfluorooctanoic acid(PFOA)as the template had good imprinting effects and could selectively remove PFOS from aqueous solution.The sorption behaviors including sorption kinetics,isotherms,and effect of pH,salt,and competitive anions were investigated.Experimental results showed that the sorption of PFOS on the MIP adsorbents was very fast,pHdependent,and highly selective.The achieved fast sorption equilibrium within 1 h was attributed to the surface sorption on the fine adsorbents.The sorption isotherms showed that the sorption selectivity of PFOS on the MIP adsorbents decreased at high PFOS concentrations,which may be due to the double-layer sorption and the formation of PFOS micelles on the sorbent surface.The sorption of PFOS on the MIP adsorbents was mainly dominated by the electrostatic interaction between the protonated vinylpyridine on the adsorbent surface and the anionic PFOS.The prepared MIP adsorbents can potentially be applied in water and wastewater treatment for selective removal of PFOS.
基金financially supported by the National Natural Science Foundation of China (22078132 and 22108103)Open Funding Project of the National Key Laboratory of Biochemical Engineering (2021KF-02)+3 种基金China Postdoctoral Science Foundation (2021M691301)Jiangsu Agricultural Independent Innovation Fund Project (CX(21)3079)Graduate Research Innovation Program of Jiangsu Province (KYCX20-3040)China Postdoctoral Science Foundation (2021M691301)。
文摘Molecularly imprinted polymers (MIPs) have great potential as adsorbents for selective adsorption and separation of nucleoside compounds,but effectively enhancing the affinity of recognition sites by adjusting the forces between template molecules and functional monomers remains an important challenge.In this work,a surface imprinting strategy was used to construct bowl-shaped molecularly imprinted composite sorbents (BHPN@MIPs) based on polydopamine (PDA) particles and have achieved selective separation and purification of 2'-deoxyadenosine (dA).Where by the base complementary pairing interaction of the combined template molecule d A and the pyrimidine functional monomer can enhance the preassembly force,and the hydrophilic bowl-shaped PDA can provide a larger storage space contact efficiency of d A in the test solution,causing the site utilization much higher and improving the kinetic adsorption performance.The equilibrium adsorption time and maximum adsorption capacity of60 min and 328.45μmol·g^(-1)were observed by static adsorption experiments,and the selectivity experimental results showed an imprinting factor IF of 1.30.After four adsorption–desorption cycles,the initial adsorption equilibrium adsorption capacity of BHPN@MIPs still retained 91.14%.By evaluating the selective adsorption of d A in spiked human serum solutions,BHPN@MIPs can be used to selectively enrich and analyze target d A in complex biological samples.
文摘Sulfamethoxazole(SMX)is a sulfonamide antibiotic primarily used to treat urinary tract infections and used in veterinary and industrialized husbandry to treat diseases and food additives.Like other antibiotics,SMX is considered as a pollutant in water and food that threaten local life.This study developed a surface plasmon resonance(SPR)sensor chip that is fast,highly selective,and reusable,and requires no pretreatment for detecting SMX.As a receptor,SMX imprinted methacrylic acid-2-hydroxyethyl methacrylate-ethylene glycol dimethacrylate polymer[poly(MAA-HEMA-EGDMA)]was used.The surface of the gold SPR chips was coated with a drop-casting method.The nanofilm coated chips were characterized by scanning electron microscopy(SEM),atomic force microscopy(AFM),ellipsometer,contact angle measurement,and Fourier-transform infrared spectrometry(FTIR).Imprinting factor(IF)was calculated as:ΔR[MIP(molecularly imprinted polymers)]/ΔR[NIP(non-imprinted)]=12/3.5=3.4.Limit of detection(LOD)and limit of quantification(LOQ)values were calculated with 3 s/m and 10 s/m methods,and the results were found to be 0.0011μg/L for LOD 0.0034μg/L for LOQ.Adsorption studies on both standard SMX solution and commercial milk samples were applied.Also,we investigated the developed chip’s reusability,storability,and selectivity with amoxicillin and cefalexin.
基金the National Natural Science Foundation of China for the funding(No.20771015)the 111 Project(No.B07012)
文摘A novel method to prepare surface plasmon resonance(SPR) sensor chips based on grafted imprinted polymer is explored. Benzophenone photografting system is used to grow molecularly imprinted polymer(MIP) films from the modified surface of gold substrate.The surface morphology and thickness of MIP films were investigated by scanning electronic microscope(SEM).The adsorption properties of sensor chip were studied by SPR spectroscopy.The results demonstrate that nano-MIP films can be constructed on the surface of gold substrate with the good adsorption of template molecules.