Lei Li

Bio: Lei Li is an academic researcher. The author has contributed to research in topics: Molecularly imprinted polymer & Molecular imprinting. The author has an hindex of 5, co-authored 6 publications receiving 117 citations.

Synthesis, properties and application research of atrazine Fe3O4@SiO2 magnetic molecularly imprinted polymer

Abstract: Magnetic Fe3O4 nanoparticles were prepared by coprecipitation and then were coated with SiO2 on the surface Fe3O4@SiO2 composite microspheres were modified by KH570 Using molecular imprinting technology, atrazine magnetic molecularly imprinted polymer was prepared by using atrazine as template molecule, methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linkers The morphology, composition and magnetic properties of magnetic nanoparticles were characterized The recognition selectivity of polymer was studied for template molecule and simulation by UV spectrophotometry The adsorption properties and selectivity ability were analyzed by Scatchard analysis Scatchard linear regression analysis indicated that there are two binding sites of the target molecules The magnetic molecularly imprinted polymer has been applied to the analysis of atrazine in real samples The results show that: the recovery rates and the relative standard deviation were 940∼987% and 21∼40% in corn, the recovery rates and the relative standard deviation were 887∼935% and 28∼72% in water

Electrospun Nanofiber Membranes Containing Molecularly Imprinted Polymer (MIP) for Rhodamine B (RhB)

Abstract: 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).

Molecularly imprinted polymer coating with fluorescence on magnetic particle

Abstract: In this research, molecular imprinting technology was employed to prepare magnetic, fluorescent molecularly imprinted polymer microspheres (fluorescent M-MIP) for recognition and separation of endocrine disrupting chemicals. The fluorescent M-MIP were prepared using Fe3O4@SiO2 magnetic nanoparticles combined with fluorescein (isothiocyanate) as fluorescent material with the surface molecularly imprinting method. The magnetic fluorescent molecularly imprinted polymers were characterized by fluorescence spectrophotometer, X-ray powder diffraction, vibration sample magnetic field meter, scanning and transmission electron microscopic methods. The results showed that the fluorescent M-MIP not only had excellent superparamagnetism and maintained the crystalline structure of the magnetic nanoparticles, but also stable fluorescence. The recognition selectivity of the magnetic fluorescence polymer was studied for template molecule and analogues. The results indicated that the fluorescent quenches of bisphenol A (the selective target) for fluorescent M-MIP were higher than that of the structural analogues, which illustrated the recognition selectivity for bisphenol A. Simultaneously, the fluorescent magnetic non-imprinted polymers (M-NIPs) had much higher fluorescent quenches than the fluorescent M-NIPs in the processes of rebinding. Therefore, the fluorescent M-MIP technology can be used for the recognition, magnetic separation and detection of bisphenol A by fluorescence spectrometry without any time-consuming elution. Open image in new window

Magnetic molecularly imprinted polymer for separating atrazine, and preparation method for magnetic molecularly imprinted polymer

Abstract: The invention discloses a method for preparing a magnetic molecularly imprinted polymer for separating atrazine. The method comprises the following steps of: 1) activating Fe3O4atSiO2 particles, and performing surface modification by using a silane coupling agent to obtain composite magnetic nano-particles; and 2) adding the atrazine and methacrylic acid into an organic solvent and preassembling,adding the composite magnetic nano-particles, a crosslinking agent and an initiator, performing polymerization reaction at the temperature of between 60 and 70 DEG for 20 to 24h in an anaerobic environment, and removing the atrazine to obtain the magnetic molecularly imprinted polymer. The method is easy to operate and is suitable for large-scale production; the time consumption is low; raw materials are cheap and readily available; and membrane materials with micron-scale and nano-scale diameters can be obtained. The invention also provides the magnetic molecularly imprinted polymer preparedby the method. Magnetic molecules are firmly combined, and the magnetic molecularly imprinted polymer is high in stability and has stronger adsorption capacity when separating the atrazine.

Molecularly Imprinted Membranes: Past, Present, and Future

Abstract: More than 80 years ago, artificial materials with molecular recognition sites emerged. The application of molecular imprinting to membrane separation has been studied since 1962. Especially after 1990, such research has been intensively conducted by membranologists and molecular imprinters to understand the advantages of each technique with the aim of constructing an ideal membrane, which is still an active area of research. The present review aims to be a substantial, comprehensive, authoritative, critical, and general-interest review, placed at the cross section of two broad, interconnected, practical, and extremely dynamic fields, namely, the fields of membrane separation and molecularly imprinted polymers. This review describes the recent discoveries that appeared after repeated and fertile collisions between these two fields in the past three years, to which are added the worthy acknowledgments of pioneering discoveries and a look into the future of molecularly imprinted membranes. The review begins ...

Biocompatibility of magnetic Fe3O4 nanoparticles and their cytotoxic effect on MCF-7 cells

Abstract: Background The objective of this study was to evaluate the synthesis and biocompatibility of Fe3O4 nanoparticles and investigate their therapeutic effects when combined with magnetic fluid hyperthermia on cultured MCF-7 cancer cells.