Trace bensulfuron‐methyl analysis in tap water,soil, and soybean samples by a combination of molecularly imprinted stir bar sorption extraction and HPLC‐UV

A molecularly imprinted stir bar was prepared using bensulfuron‐methyl as the template molecule and methacrylic acid as the functional monomer. The imprinted and nonimprinted stir bars were characterized by scanning electron microscopy, nitrogen sorption porosimetry, thermogravimetric analysis, and differential scanning calorimetry. Extraction time, desorption time and pH value affecting extraction efficiency of the stir bar have been evaluated to achieve the selectively direct preconcentration of the template from aqueous samples. Competitive sorption experiments demonstrated that the imprinted stir bar gave high selectivity and imprinted effect on the template bensulfuron‐methyl compared to the nonimprinted stir bar. Based on S/N of 3, LOD was 0.83 nM. The method showed good recoveries and precision, 92.4% (RSD 1.5%, n = 3) for tap water spiked with 126 ng (100 mL sample), 84.6% (RSD 2.2%, n = 3) for soil spiked with 210 ng (100 g sample) and 73.7% (RSD 2.1%, n = 3) for soybean spiked with 250 ng (5 g sample), suggesting that the imprinted stir bar sorption extraction can be successfully applied to the preconcentration of bensulfuron‐methyl in real samples. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Computer simulation and synthesis of stimuli‐responsive polymer by sol‐gel for selective recognition of (4‐chloro‐2‐methylphenoxy)acetic acid

A novel photoresponsive functional monomer bearing a siloxane polymerizable group and azobenzene moieties was synthesized, and then photoresponsive molecularly imprinted sol‐gel polymers were successfully fabricated from the synthesized functional monomer, using (4‐chloro‐2‐methylphenoxy)acetic acid (MCPA) as a molecular template. The photoisomerization properties of the functional monomer are retained after incorporation into the rigid three‐dimensional crosslinked polymer matrix. The template is then removed from the resulting polymer to generate pores, which are complementary to the template in shape, size and functionality. The substrate affinity of the molecularly imprinted polymer (MIP) receptor sites is photoswitchable. This can be attributed to the photoisomerization of azobenzene chromophores within the MIP receptors, resulting in alteration of their geometry and the spatial arrangement of their binding functionalities. The binding affinity of the imprinted recognition sites was switchable by alternate irradiation with UV and visible light, suggesting that azobenzene groups located inside the binding sites could be used as chemical sensors and the trans–cis isomerization could regulate the affinity for MCPA. To study the hydrogen bond interactions between template molecules and functional monomer, computational molecular modeling was employed. The data indicate that the design of the MIP is rational. Copyright © 2012 Society of Chemical Industry     

Equilibrium and kinetic isotherms and parameters for molecularly imprinted with sclareol poly(acrylonitrile‐co‐acrylic acid) matrix

The present work continues the previous studies concerning the synthesis and characterization of molecularly imprinted polymers (MIPs) with sclareol as template and three poly(acrylonitrile‐co‐acrylic acid) (AN:AA) copolymers with different ratios between monomers as matrices. The previous studies of rheology, elemental analysis, infrared spectroscopy, size exclusion chromatography, thermogravimetry, differential scanning calorimetry, batch rebinding tests, and Scatchard analysis, which confirmed the molecular imprinting, are being completed with the current equilibrium and kinetic adsorption studies. For this purpose, eight adsorption isotherms and three kinetic adsorption models were applied to six sets of experimental data obtained after three sclareol‐imprinted adsorbents (MIPs) and three nonimprinted adsorbents (NIPs) were submitted to batch adsorption experiments. After ordering the adsorption models according to the “minimum sum of normalized errors (SNE)” criteria, it was concluded that the adsorption in sclareol imprinted AN:AA copolymers is characterized by low surface coverage, takes place on heterogeneous binding sites and is reversible, while for NIPs the results suggest a difficult adsorption and/or easiness of template extraction, and that NIPs have homogeneous, but nonimprinted micropores. For the kinetic experiments, the minimum SNE for MIPs points to the first order kinetic model, fact that suggests a physical adsorption of template molecules on the imprinted sites. POLYM. ENG. SCI., 55:1152–1162, 2015. © 2014 Society of Plastics Engineers     

Molecularly imprinted fluorescent polymers as chemosensors for the detection of mercury ions in aqueous media

This article describes the investigation of molecularly imprinted fluorescent polymer membranes as sensing receptors for Hg²⁺ detection by an optical approach. The polymers were synthesized with 4‐vinylpyridine as a functional monomer and Hg²⁺ as a template; 9‐vinylcarbazole was used as both a complex‐forming agent and a fluorescence probe. The free‐radical polymerization was performed within a semicylindrical Teflon mold and was initiated by 2,2′‐azobisisobutyronitrile at 60°C. The template, ion‐bonded to pyridine and carbazole groups in the polymer membrane, was removed by acid treatment. Attenuated total reflectance–Fourier transform infrared (FTIR) spectroscopic measurements and scanning electron microscopy images were used to compare the chemistry and surface morphology, respectively, of both imprinted and nonimprinted polymer materials. The final polymer membranes with semicylindrical shapes were used directly to determine Hg²⁺ concentration in aqueous solutions by the monitoring of the fluorescence intensity of the carbazole groups quenched upon complex formation with metal ions. The values of the Hg²⁺ binding ratio for the imprinted and nonimprinted polymeric membranes were compared, and the results indicate the superior sensitivity and selectivity of the imprinted membranes. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Imprinted microspheres doped with carbon nanotubes as novel electroresponsive drug‐delivery systems

Novel molecularly imprinted polymers (MIPs) suitable for the electroresponsive release of diclofenac were synthesized by precipitation polymerization in the presence of carbon nanotubes (CNTs). Both conventional and electroresponsive imprinted polymers were synthesized with methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the crosslinker. Preliminary experiments were performed to fully characterize the conventional MIPs and composite materials in terms of their morphological properties, recognition behavior, and electric resistivity. In vitro release experiments were performed in aqueous media to elucidate the ability of the MIPs and spherical imprinted polymers doped with CNTs to release the loaded template in a sustained manner over time in comparison to the that of the corresponding nonimprinted materials. Furthermore, a 20‐V direct‐current voltage was applied through the releasing media to evaluate how the electric field influenced the drug release to demonstrate the suitability of the proposed macromolecular system as an electroresponsive drug‐delivery device. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 829‐834, 2013     

Evaluation of a new water‐compatible hybrid molecularly imprinted polymer combined with restricted access for the selective recognition of folic acid in binding assays

This article deals with the synthesis of an organic?inorganic hybrid molecularly imprinted poly(methacrylic acid‐trimethylolpropane trimethacrylate)/SiO₂ combined with restricted access. Fourier Transform Infrared Spectroscopy, Transmission Electron Microscopy, Thermogravimetric Analysis, and textural data were used to characterize the structure of material. Higher selectivity was obtained for the molecularly imprinted polymer with restricted access when compared to nonimprinted polymer with restricted access, confirming the imprinting effect. The folic acid sorption for the polymers molecularly imprinted with restricted access, nonimprinted with restricted access, and molecularly imprinted, exhibited the following values of 5.6, 4.5, and 4.8 mg g^?1, respectively. Kinetic experimental data were very well adjusted to Elovich and pseudo‐second‐order models, which suggest that the sorption of folic acid takes place in binding sites with different energies. The obtained values of enthalpy, entropy and Gibbs free energy of ?12.79 kJ mol^?1, ?36.38 K^?1 J mol^?1, and ?1.76 kJ mol^?1, respectively, showed that the sorption of folic acid onto molecularly imprinted polymer combined with restricted access occurs spontaneously, is of both exothermic and of physical nature with an increase of ordering at the solid?solution interface. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43463.     

Fabrication of ordered microporous styrene‐acrylonitrile copolymer blend imprinted membranes for selective adsorption of phenol from salicylic acid using breath figure method

Highly selective, ordered microporous molecularly imprinted membranes (MIMs) for phenol were synthesized by breath figure (BF) method using styrene‐acrylonitrile copolymer (SAN) as the membrane matrix and molecularly imprinted polymer nanoparticles (nano‐MIPs) as the imprinted nanoparticles. The nano‐MIPs were synthesized by oil‐in‐water emulsion polymerization using 4‐vinyl pyridine (4‐VP), methyl methacrylate (MMA) or cinnamic acid (CA) as the functional monomer, respectively. The prepared nano‐MIPs were characterized by transmission electron microscope (TEM) and Raman, whereas MIMs were characterized by SEM, membrane flux, and selective adsorption experiments. Morphological analysis exhibited that the addition of nano‐MIPs improved the formation of ordered and well‐defined porous membrane morphology. Compared with MMA‐MIM and CA‐MIM, the 4‐VP‐MIM exhibited higher membrane flux, adsorption capacity, and stronger selective binding for phenol as well as excellent permeation selectivity for phenol. Moreover, the selective effect of 4‐VP‐MIM on phenol was strongly affected by the amount of 4‐VP imprinted nanoparticles (nano‐4‐VP‐MIPs). The experimental data revealed that the 4‐VP‐MIM containing 2.0 wt % of nano‐4‐VP‐MIPs exhibited the highest separation selectivity for the template phenol, whose selectivity coefficients for phenol relative to salicylic acid (SA) and p‐hydroxybenzoic acid (p‐HB) were 5.6770 and 5.5433, respectively, which was close to the predicted selectivity coefficient value. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42350.     

Synthesis of ion‐imprinting chitosan/PVA crosslinked membrane for selective removal of Ag(I)

A novel ion‐imprinted membranes were synthesized for selective removal and preconentration for Ag(I) ions from aqueous solutions. The membranes were obtained via crosslinking of chitosan (CS), PVA, and blend chitosan/PVA using glutaraldehyde (GA) as crosslinker. The FTIR spectra were used to confirm the membrane formation. Comparing with the nonimprinted membranes, Ag(I)‐imprinted CS and CS/PVA has higher removal capacity and selectivity for Ag⁺ ions. An enhancement in the Ag⁺ removal capacity by ～ 20% (from 77.8 to 94.4 mg g^–1) and ～ 50% (from 83.9 to 125 mg g^–1) was found in the Ag(I)‐imprinted CS and Ag(I)‐imprinted CS/PVA membranes, respectively, when compared with the nonimprinted membranes. Removal equilibra was achieved in about 40 min for the non‐ and ion‐imprinted CS/PVA. The pH and temperature significantly affected the removal capacity of ion‐imprinted membrane. The relative selectivity coefficient values of Ag⁺/Cu²⁺ and Ag⁺/Ni²⁺ are 9 and 10.7 for ion‐imprinted CS membrane and 11.1 and 15 for ion‐imprinted CS/PVA membrane when compared with nonimprinted membranes. The imprinted membranes can be easily regenerated by 0.01M EDTA and therefore can be reused at least five times with only 15% loss of removal capacity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis of molecularly imprinted microspheres for recognition of trans‐aconitic acid

In the presence of a template molecule, trans‐aconitic acid and, using acetonitrile as solvent and dispersing medium, monodispersed microspheres with a diameter of 600–700 nm bearing molecularly imprinted binding sites were prepared by precipitation polymerization. It was found that the concentrations of template, monomer, and crosslinking agent as well as the chemical structure of the template greatly affect the polymer configuration. Microspheres are produced only when the concentration of the template molecule and the functional monomer are finely tuned. Comparison with the performance of a conventional imprinted polymer monolith showed that the imprinted microsphere had obvious advantages in specific binding to template molecule. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 542–547, 2004     

Preparation and evaluation of magnetic imprinted polymers for 2,4,6‐trinitrotoluene by surface imprinting

A safe and facile approach for the preparation of magnetic molecularly imprinted polymer nanospheres for 2,4,6‐trinitrotoluene (TNT) recognition is reported. The imprinted nanospheres were synthesized using TNT as the imprinting molecule, acrylamide as the functional monomer, N,N'‐methylenebisacrylamide as the crosslinker and magnetic particles as the support. The structure of the materials was identified via Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy and transmission electron microscopy. Static adsorbing experiments were carried out and Scatchard plot analysis showed that two kinds of receptor sites were formed in the imprinted materials. The adsorption equilibrium constant and the maximum adsorption capacity were evaluated. These results indicated that the imprinted nanospheres have higher adsorption capacity and selectivity for TNT than non‐imprinted polymer nanospheres with the same composition. © 2013 Society of Chemical Industry     

The preparation of molecularly imprinted poly(o‐phenylenediamine) membranes for the specific O,O‐dimethyl‐α‐hydroxylphenyl phosphonate sensor and its characterization by AC impedance and cyclic voltammetry

A molecularly imprinted polymer (MIP) membrane for sensing O,O‐dimethyl‐α‐hydroxylphenyl phosphonate (DHP) has been prepared by electropolymerizing o‐phenylenediamine on the glassy carbon electrodes in the presence of DHP. Optimization studies with the aim to enhance insulating properties and response kinetics of the polymer membrane were carried out with respect to template molecular concentration, the monomers concentration, the polymer membrane thick and scan rate. Cyclic voltammetry and electrochemical impedance have been used to characterize the behavior of MIP polymer membrane. The capacitive measurements were also certified the imprinting effect of the polymer layers. The experimental results showed that DHP imprinted polymer has better recognition property for the template than that of a blank polymer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2222–2227, 2006     

Fabrication of pH‐responsive molecularly imprinted polyethersulfone particles for bisphenol‐A uptake

pH‐responsive molecularly imprinted particles were successfully fabricated by pore‐filling poly (acrylic acid) (PAA) gels into bisphenol‐A (BPA)‐imprinted polyethersulfone particles. The adsorbed BPA amount (or rate) decreased after filling the PAA gels both for the imprinted and nonimprinted particles. However, it was confirmed that changing the acidity of the solution reversibly controls the rebinding ability toward BPA and that the BPA uptake of the pore‐filled particles exhibited chemical valve behavior at a pH between 3 and 6. This finding can be attributed to the swelling of the PAA gels in the particles. The present methodology provides a simple way to prepare pH‐responsive molecularly imprinted materials and is expandable to the imprinting of other hydrophobic molecules, such as dibenzofuran. Also, the results of this work demonstrate the potential of stimuli‐responsive molecularly imprinted polymer materials as smart chemicals and as drug‐delivery systems. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation of pH and temperature dual‐sensitive molecularly imprinted polymers based on chitosan and N‐isopropylacrylamide for recognition of bovine serum albumin

pH and temperature dual‐sensitive protein imprinted microspheres with high absorption capacity have been successfully synthesized on the surface of SiO₂ using chitosan grafted N‐isopropylacrylamide (CS‐g‐NIPAM) as the pH and temperature sensitive monomer, with acrylamide as comonomer, N,N′‐methylenebisacrylamide as the crosslinking agent and bovine serum albumin (BSA) as the template protein. The pH and temperature dual‐sensitivity was also investigated. The results showed that the adsorption capacity and imprinting factor improved slowly with increasing incubation pH from 4.6 to 7.0, and then decreased sharply in alkaline conditions due to the reduction of non‐specific binding from electrostatic and hydrogen bonding interactions. Fourier transform infrared spectroscopy, thermogravimetric analysis and transmission electron microscopy were used to characterize the polymers. The as‐prepared SiO₂@BSA molecularly imprinted polymers were also found to have high adsorption capacity (119.88 mg g^?1) within 2 h, an excellent imprinting factor (α = 2.25), specific selectivity and good reusability. © 2019 Society of Chemical Industry     

A molecularly imprinted polymer via a salicylaldiminato‐based cobalt(III) complex: A highly selective solid‐phase extractant for anionic reactive dyes

A novel molecularly imprinted polymer based on tert‐butyl acrylate (MIP‐BA) was fabricated with the assistance of a cobalt(III)‐based catalyst bearing an N‐salicylidene isopropylamine ligand [(SPA)₂CoCl]. After initiation with methyl aluminoxane, the catalyst system was found to be active toward the polymerization of tert‐butyl acrylate (t‐BA) in the presence of a polar template (Cibacron reactive red dye) and divinylbenzene (DVB) as a crosslinker. Polymerization experiments, including those of t‐BA, t‐BA, and DVB and t‐BA and dye, were also carried out. Isolated blank polymers and MIP‐BA were analyzed with a variety of techniques, including differential scanning calorimetry, thermogravimetric analysis, gel permeation chromatography, infrared spectroscopy, nuclear magnetic resonance, and ultraviolet–visible spectroscopy. In general, the complex showed moderate polymerization activity and produced high‐molar‐mass poly(tert‐butyl acrylate); however, a decrease in the monomer conversion was observed upon the addition of the dye and/or the crosslinker. The effect of imprinting was obvious when the adsorption capacity of MIP‐BA measured at pH 6 for red dye (the imprinted molecule) was increased from 9.2 to 90.4 mg/g after imprinting. Competitive adsorption studies revealed that the dye‐imprinted polymer enabled the efficient uptake of red dye, even in the presence of blue and yellow dyes that had similar chemical structures to the imprinted molecule. The selectivity coefficients were 43 and 36 with respect to the blue and yellow dyes, respectively. The proposed polymerization procedure could be extended to other anionic polar reactive dyes and polar reactive polymers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Molecularly imprinted nanoparticles prepared by core‐shell emulsion polymerization

Submicron core‐shell polymer particles, with molecularly imprinted shells, were prepared by a two‐stage polymerization process. Particles of this type, prepared with a cholesterol‐imprinted ethyleneglycol dimethacrylate shell and in the absence of porogen, were found to be 76 nm in diameter with a surface area of 82 m² g⁻¹. Cholesterol uptake from a 1 mM solution in isohexane was measured at both 10 and 30 mg mL⁻¹, with the imprinted polymer showing considerable binding (up to 57%). Imprinted but not hydrolyzed and hydrolyzed nonimprinted polymers showed very low uptakes (≤4.5%) and a phenol‐imprinted polymer showed reduced binding (36%) under the same conditions. Imprinted shells were also prepared over superparamagnetic polymer cores and over magnetite ferrocolloid alone. The cholesterol binding to magnetic particles was very similar to that of equivalent nonmagnetic materials. Magnetic particles could be sedimented in as little as 30 s in a magnetic field. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1851–1859, 2000     

Ibuprofen‐imprinted ultrathin poly[N‐(2‐hydroxypropyl) methacrylamide] films

Surface molecularly imprinted (MIP) poly[N‐(2‐hydroxypropyl) methacrylamide] [poly(HPMA)] films were prepared via interface‐mediated reversible addition‐fragmentation chain transfer (RAFT) polymerization from 4‐cyano‐4‐(propylsulfanylthiocarbonyl) sulfanyl pentanoic acid immobilized silicon substrate using N‐(2‐hydroxypropyl) methacrylamide as the functional monomer, N,N′‐methylene(bis)acrylamide as the crosslinking agent, and ibuprofen as the template molecule. The highly crosslinked MIP layer (～12 nm) was homogeneously grafted onto the silicon surface, which favors fast mass transfer and rapid binding kinetics. Binding capacities and adsorption parameters of the MIP poly(HPMA) films were calculated from the root‐mean‐square roughness data obtained by atomic force microscopy measurements using the Luzinov and Langmuir equations adopted for this study. The target binding assays demonstrate the desirable binding capacity and imprinting efficiency of the MIP poly(HPMA) films. Meanwhile, the computational optimization and energy calculations showed the formation of the self‐assembly of monomer and template molecule via noncovalent interactions that leads to a 1:4 molecular complex between ibuprofen and N‐(2‐hydroxypropyl) methacrylamide. This study provides a versatile approach to the quantitative determination of low‐molecular‐weight biomolecules on surface‐imprinted polymers. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45707.     

Using polystyrene‐co‐maleic acid for molecularly imprinted membranes prepared in supercritical carbon dioxide

Supercritical CO₂ (ScCO₂) has been used to prepare molecularly imprinted polymers of poly(styrene‐co‐maleic acid) (PSMA) for targeted uracil (URA). The condition of ScCO₂ was on 16 MPa between 35 and 50°C. The resultant imprinted membranes prepared at 35 and 50°C bound URA with 9.2 ± 0.10 and 12.6 ± 0.06 μmol g⁻¹, respectively. Competitive binding studies were undertaken in binary substrate solution containing each of URA/DMURA, URA/Thymine, and URA/Cytosine with 2 μM. The URA imprinted membrane showed high separation factor (α) with 17 for both URA/DMURA and URA/Thymine and for URA/Cytosine, α = 13. Results strongly suggested that the URA imprinted membrane had effective selectivity hydrogen bonding to separately bind in the binary components to the template. Effect of organic solvents on the URA imprinting in ScCO₂ was also studied, in addition to comparison of properties with those obtained in both ScCO₂ and water. Evidence presented that ScCO₂ medium was effective to prepare the URA imprinted membrane. We discussed that ScCO₂ fluid was efficient to fix the shape of URA template into the PSMA membrane through hydrogen bonding. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis of novel photoresponsive molecularly imprinted polymer microspheres with special binding properties

An azobenzene‐containing molecularly imprinting polymer microsphere with photoresponsive binding properties toward 2,4‐dichlorophenoxyacetic acid (2,4‐D) was successful prepared via silica surface polymerization. The number‐average diameters of silica and imprinting polymer microsphere are 0.5 and 0.7 μm, respectively. The static adsorption, binding and selectivity experiments were performed to investigate the adsorption properties and recognition characteristics of the polymers for 2,4‐D. The equilibrium adsorptive experiments indicated that 2,4‐D‐SMIP(surface molecularly imprinted polymers) has significantly higher adsorption capacity for 2,4‐D than its nonimprinted polymers (SNIP).The binding constant K_d and apparent maximum number Q_max of the imprinted polymer were determined by Scatchard analysis as 0.054 mmol L^?1 and 0.167 mmol g^?1_, respectively. The result of photoregulated release and uptake of 2,4‐D experiment demonstrated that azo‐containing SMIP can make use of light and change it into mechanical properties to release and take up the template molecules. It means that the SMIP can be controlled by light. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 869‐876, 2013     

Binding behavior of Fe3+ ions on ion‐imprinted polymeric beads for analytical applications

We used a molecular imprinting approach to achieve specific metal binding utilizing N‐methacryloyl‐(L )‐cysteine methyl ester (MAC) as a metal‐complexing ligand. MAC was synthesized using methacryloyl chloride and cysteine methyl ester. Then, Fe³⁺ was complexed with MAC monomer. Fe³⁺‐imprinted poly(hydroxyethyl methacrylate‐N‐methacryloyl‐(L )‐cysteine methyl ester) [poly(HEMA‐MAC)] beads with average size of 63–140 μm were produced by suspension polymerization. After that, the template ions (i.e. Fe³⁺ ions) were removed by 0.1M HCl. Fe³⁺‐imprinted beads were characterized by swelling studies, FTIR, and elemental analysis. The Fe³⁺‐imprinted beads with a swelling ratio of 72%, and containing 3.9 mmol MAC/g were used in the binding of Fe³⁺ ions from aqueous solutions, tap water, certified reference serum sample, and real serum sample. Maximum binding capacity, optimum pH, and equilibrium binding time were 107 μmol/g, pH 3.0, and 30 min, respectively. It was observed that even in the presence of other ions, Fe³⁺‐imprinted beads selectively bound Fe³⁺ ions with 97% efficiency. Removal of Fe³⁺ ions from certified reference serum sample was approximately found to be 33%. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3520–3528, 2006     

A pH‐controllable imprinted composite membrane for selective separation of podophyllotoxin and its analog

A molecularly imprinted composite membrane (MICM) with pH‐controllability and selectivity to podophyllotoxin (PPT) was prepared using a polyvinylidene fluoride (PVDF) microfiltration membrane as the support. The functional monomer is 1‐phenyl‐3‐methyl‐4‐methacryloyl‐5‐pyrazolone (PMMP), which is a new β‐diketone compound with enol/ketol tautomerization. In this study, imprinting parameters, including the amounts of functional monomer and cross‐linker, and immersion time of membrane in the imprinting solution, were optimized by equilibrium adsorption experiments. Pore structure and surface morphology of the optimal MICM (MICM₂) was characterized. Finally, competitive permeability of PPT in the presence of its analog 4′‐demethylpodophyllotoxin (DMEP) was measured under the drive of concentration difference. The results reveal that the surface morphology and pore structure of MICM₂ are structurally different from those of the control nonimprinted membrane. As a result, MICM₂ could efficiently recognize PPT in a complex system due to a better structural matching and the interaction between the functional groups of MICM₂ and PPT. However, the most interesting finding is its pH‐controllability. The membrane could switch the preference to either PPT or DMEP with the change of pH values in the sample solution. At pH values smaller than 8.4, it led to a faster transportation of PPT, while the situation reversed to DMEP at pH values greater than 8.4. This peculiar property would lead this imprinted membrane to have potential application in the separation and enrichment of PPT, and the new functional monomer PMMP exhibited an attractive application prospect in the functional material fields. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013