A simple method for the formation of molecularly imprinted membrane of Rhodamine B (RhB) was developed by electrospinning. RhB molecularly imprinted microspheres were produced by precipitation polymerization using RhB...A simple method for the formation of molecularly imprinted membrane of Rhodamine B (RhB) was developed by electrospinning. RhB molecularly imprinted microspheres were produced by precipitation polymerization using RhB, acrylamide, ethylene glycol dimethacrylatea (EGDMA), azobisisobutyronitrile (AIBN) and acetonitrile as template, functional monomer, cross-linking agent, initiator and porogen, respectively. Then molecularly imprinted membranes (MIMs) were produced via electrospinning technique with polyethylene terephthalate (PET) as the matrix polymer. The as-prepared nanofiber membranes were characterized by scanning electron microscopy (SEM). Optimization studies with the aim to enhance the MIP selection adsorption were carried out with respect to the amount of membrane, pH and adsorption time. Linear range and detection limit were 0.01 ~ 20 μmol/L and 2.0 × 10-3 μmol/L, respectively. HPLC analysis showed that in the optimized conditions of separation and enrichment, the recovery rate can reach 97.8% ~ 117.1%, relative standard deviation (n = 3) was 1.36% ~ 2.19% in employing MIMs to the RhB simulated water samples. The results showed that the imprinted polymer exhibited higher affinity for Rhodamine B compared to non-molecularly imprinted polymers membranes (NIMs) and molecularly imprinted particles (MIP).展开更多
Chinese herbal medicines(CHMs)play an increasingly important role in the field of medicine and affects public health in the world.Although more and more strict has been employed to ensure the quality and safety of CHM...Chinese herbal medicines(CHMs)play an increasingly important role in the field of medicine and affects public health in the world.Although more and more strict has been employed to ensure the quality and safety of CHMs,pesticide residues in CHMs remain a serious issue and are the bottleneck for the global development of CHMs.In this work,we applied molecularly imprinted membrane electrospray mass spectrometry(MIM-ESI MS)for rapid detecting 4 classes of pesticide residues in CHMs,including organophosphorus(OPP),carbamates,pyrethroids and neonicotinoids in CHMs.Compared with our previous ambient ionization method MESI,MIM-ESI is capable of achieving a~50-fold increase in the detection limit of conventional analytical methods owing to the specificity recognition and unique enrichment of MIM.The optimal experimental conditions were determined,and the method was further validated for its sensitivity and specificity.Our data showed that MIM-ESI MS is applicable for the direct quantitation of pesticide residues in CHMs.This detection technology may help to ensure the quality of CHMs in the future.展开更多
Molecularly imprinted membrane-zinc porphyrin-mathacrylate（MIM-Zn-MAA）, a dual read-out sensor based on a molecularly imprinted membrane, was developed to recognize and detect dimethyl methylphosphonate （DMMP） as ...Molecularly imprinted membrane-zinc porphyrin-mathacrylate（MIM-Zn-MAA）, a dual read-out sensor based on a molecularly imprinted membrane, was developed to recognize and detect dimethyl methylphosphonate （DMMP） as an intermediate molecule of organophosphorus pesticides. The membranes were prepared via thermal polymerization of two functional monomers（zinc porphyrin and mathacrylate） on the surface of a glass slide functio- nalized with ethylene glycol dimethacrylate and azobisisobutyronitrile. The morphology of the as-synthesized MIM-Zn-MAA was determined with scanning electronic microscopy. The composite membranes exhibited macrovoid morphologies, which were affected by the functional monomers. These membranes were selectively adsorbed onto the template molecule and displayed higher adsorbing capacity toward DMMP compared with their structural analogs Changes in the fluorescent spectra were qualitatively and quantitatively monitored via fluorescence photometry. Dif- ference maps were also obtained using colorimetry before and after the reaction between MIM-Zn-MAA and DMMP at various concentrations. The maps showed a wide linear range varying from 0.1 lamol/L to 10 mmol/L with a low detection limit of 0.1 lamol/L. These preliminary results demonstrate that the as-fabricated dual read-out sensor dis- plays good sensitivity and selectivity toward DMMP, indicating its considerable potential in DMMP detection in practical applications.展开更多
文摘A simple method for the formation of molecularly imprinted membrane of Rhodamine B (RhB) was developed by electrospinning. RhB molecularly imprinted microspheres were produced by precipitation polymerization using RhB, acrylamide, ethylene glycol dimethacrylatea (EGDMA), azobisisobutyronitrile (AIBN) and acetonitrile as template, functional monomer, cross-linking agent, initiator and porogen, respectively. Then molecularly imprinted membranes (MIMs) were produced via electrospinning technique with polyethylene terephthalate (PET) as the matrix polymer. The as-prepared nanofiber membranes were characterized by scanning electron microscopy (SEM). Optimization studies with the aim to enhance the MIP selection adsorption were carried out with respect to the amount of membrane, pH and adsorption time. Linear range and detection limit were 0.01 ~ 20 μmol/L and 2.0 × 10-3 μmol/L, respectively. HPLC analysis showed that in the optimized conditions of separation and enrichment, the recovery rate can reach 97.8% ~ 117.1%, relative standard deviation (n = 3) was 1.36% ~ 2.19% in employing MIMs to the RhB simulated water samples. The results showed that the imprinted polymer exhibited higher affinity for Rhodamine B compared to non-molecularly imprinted polymers membranes (NIMs) and molecularly imprinted particles (MIP).
基金supported by the National Natural Science Foundation of China(No.82072247)to MZthe Young Scholar Project of Beijing University of Chinese Medicine(Nos.2019-JYBJS-017 and 2021-JYB-XJSJJ001)to SJ and MZ。
文摘Chinese herbal medicines(CHMs)play an increasingly important role in the field of medicine and affects public health in the world.Although more and more strict has been employed to ensure the quality and safety of CHMs,pesticide residues in CHMs remain a serious issue and are the bottleneck for the global development of CHMs.In this work,we applied molecularly imprinted membrane electrospray mass spectrometry(MIM-ESI MS)for rapid detecting 4 classes of pesticide residues in CHMs,including organophosphorus(OPP),carbamates,pyrethroids and neonicotinoids in CHMs.Compared with our previous ambient ionization method MESI,MIM-ESI is capable of achieving a~50-fold increase in the detection limit of conventional analytical methods owing to the specificity recognition and unique enrichment of MIM.The optimal experimental conditions were determined,and the method was further validated for its sensitivity and specificity.Our data showed that MIM-ESI MS is applicable for the direct quantitation of pesticide residues in CHMs.This detection technology may help to ensure the quality of CHMs in the future.
基金Supported by the National Natural Science Foundation of China（No.31101284）, the Natural Science Foundation of Chongqing City, China（No.CSTC-2011BB1209）, the Fundamental Research Funds for the Central Universities of China （Nos.CQDXWL-2012-034, CQDXWL-2012-035, CDJPY1222 0001） and the Student Research Training Program in Chongqing University, China（Nos.CQU-SRTP-2015497, CQU-SRTP-2015502）.
文摘Molecularly imprinted membrane-zinc porphyrin-mathacrylate（MIM-Zn-MAA）, a dual read-out sensor based on a molecularly imprinted membrane, was developed to recognize and detect dimethyl methylphosphonate （DMMP） as an intermediate molecule of organophosphorus pesticides. The membranes were prepared via thermal polymerization of two functional monomers（zinc porphyrin and mathacrylate） on the surface of a glass slide functio- nalized with ethylene glycol dimethacrylate and azobisisobutyronitrile. The morphology of the as-synthesized MIM-Zn-MAA was determined with scanning electronic microscopy. The composite membranes exhibited macrovoid morphologies, which were affected by the functional monomers. These membranes were selectively adsorbed onto the template molecule and displayed higher adsorbing capacity toward DMMP compared with their structural analogs Changes in the fluorescent spectra were qualitatively and quantitatively monitored via fluorescence photometry. Dif- ference maps were also obtained using colorimetry before and after the reaction between MIM-Zn-MAA and DMMP at various concentrations. The maps showed a wide linear range varying from 0.1 lamol/L to 10 mmol/L with a low detection limit of 0.1 lamol/L. These preliminary results demonstrate that the as-fabricated dual read-out sensor dis- plays good sensitivity and selectivity toward DMMP, indicating its considerable potential in DMMP detection in practical applications.
