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Magnetic ion-imprinted polymers (MIIPs) are an innovative material that combines the selectivity of ion imprinting with the ease of separation provided by magnetic properties. Recent advancements in MIIPs have shown that they have higher selectivity coefficients compared to non-imprinted materials. The synthesis of MIIPs involves creating specific recognition sites for target ions in magnetic nanomaterials. Various nanomaterials, such as graphene oxide, carbon nanotubes, and silica, have been incorporated into the IIPs to improve their analytical performance for different environmental applications, including metal extraction, monitoring, detection, and quantification. This review stresses the need to develop new monomers with a high affinity for the target analyte and to find supporting materials with groups that facilitate the effective removal of the target analyte. It also explores the influence of experimental parameters on metal determination. [ABSTRACT FROM AUTHOR]

• Magnetic surface-imprinted polymer microspheres (Fe 3 O 4 @MIPs) were facilely prepared. • Fe 3 O 4 @MIPs showed enhanced selectivity, rapid extraction and good reusability for amphetamines. • A selective magnetic solid-phase separation method was developed for six amphetamines in water samples. • The method offers a shorter extraction time for analyzing amphetamines in water compared to other methods. Magnetic surface imprinted polymer microspheres (Fe 3 O 4 @MIPs) were successfully synthesized via Pickering emulsion polymerization, utilizing N-Methylphenethylamine as a surrogate template for amphetamine-type drugs. Fe 3 O 4 @MIPs not only possessed excellent dispersibility and enough magnetic properties in aqueous solutions, but also displayed good selectivity towards six amphetamines, with an imprinting factor ranging from 1.8 to 2.6. The adsorption kinetics closely aligned with the pseudo-second-order model, and the adsorption efficiency exceeds 80 % for each amphetamine at equilibrium. Fe 3 O 4 @MIPs were then employed as the efficient adsorbents for the extraction of amphetamine drugs. Extraction parameters, including sample pH, the mass of adsorbent, and the type and volume of eluting solvent, were carefully optimized. In combination with the high performance liquid chromatography tandem triple quadrupole mass spectrometry (HPLC-MS/MS), a selective magnetic solid-phase extraction (MISPE) method utilizing Fe 3 O 4 @MIPs was developed for the detection of six amphetamines in water samples. The limits of detection and limits of quantitation were determined to be 5.2∼23 ng L−1 and 17∼77 ng L−1, respectively. Recoveries for the six target drugs from lake water and sewage samples fell within the range of 87.2∼110 %. Additionally, the MISPE-HPLC-MS/MS method exhibited excellent repeatability, with a precision below 8.5 % at two spiking levels. The prepared Fe 3 O 4 @MIPs possessed the advantages of high selectivity, straightforward preparation, facile separation and good reusability, and was highly suitable for the efficient extraction of amphetamine-type substances in complex environmental water. [ABSTRACT FROM AUTHOR]

Novel water-compatible magnetic molecularly imprinted polymers were developed. The magnetic core was firstly grafted by methyl acrylate and ethanediamine to increase the number of amino groups, which could immobilize more templates and form high-density recognition sites. Dopamine was adopted as functional monomer and crosslinker to retighten templates and prepare hydrophilic polymers. The characterization, adsorption capability, selectivity, and reusability were investigated in detail. The limit of detection and quantification of the method were 0.01 μg mL −1 and 0.038 μg mL −1 . The experimental results exhibited that the resultant nanomaterials had high crystallinity, satisfactory magnetic property, fast kinetics, favorable adsorption capacity, excellent specificity, and pleasing recovery after a mild elution. In addition, the recoveries of the proposed method at four spiked levels analysis were between 98.4% to 101.3%. The obtained imprinted nanoparticles were used as sorbents for selective separation and determination of chlorogenic acid in Honeysuckle tea. [ABSTRACT FROM AUTHOR]

Abstract: With the combined surface imprinting technique and immobilized template strategy, molecularly imprinted magnetic nanoparticles were successfully prepared and coupled with high‐performance liquid chromatography to selectively separate and determine gallic acid from the pomegranate rind. On the surface of carboxyl‐functionalized magnetic nanospheres, thin imprinting shells were formed using dopamine as monomer and crosslinker. The characteristics, polymerization conditions, and adsorption performances of the resultant nanomaterials were investigated in detail. In addition of good crystallinity, satisfactory magnetism, and uniform morphology of the obtained polymers, they had rapid binding kinetics, high adsorption capacity, and favorable reusability. In the mixed solution of four hydroxybenzoic acids, the prepared nanomaterials have an excellent selectivity to gallic acid with an imprinting factor of as high as 17.5. Therefore, the polymers have great potentials in specific extraction and enrichment of gallic acid from the complex natural resources. [ABSTRACT FROM AUTHOR]

Herein, we presented a simple synthetic strategy for fabricating magnetic nanoparticles uniformly dispersed on the surface of attapulgite (ATP), namely the impregnation and pyrolysis method. Subsequently, using magnetic attapulgite as supported core through chemical modification, a novel surface molecularly imprinted nanomaterial (named as MATP/MIPs) was prepared via precipitation polymerization. The obtained MATP/MIPs showed excellent properties by a variety of characterizations including FT-IR, SEM, TEM, VSM, XRD and TGA. Moreover, the adsorption experiments were carried out in aqueous medium at different temperatures, to study the adsorption isotherm, adsorption kinetics and selective recognition ability of MATP/MIPs toward sulfamethazine (SMZ). The experimental data were fitted to the Freundlich isotherm model better than to the Langmuir model. The equilibrium adsorption capacity for SMZ onto MATP/MIPs is higher than onto MATP/NIPs, demonstrating the existence of imprinted cavities. Due to the advantage of coated nanoshell, the adsorption equilibrium was achieved quickly within 45min, and the data were well-described by the pseudo-second-order kinetic mode. Compared with other antibiotics, the MATP/MIPs exhibited excellent selectivity for SMZ. In addition, the imprinted material still showed good regeneration ability after 10 cycles which make it possible for practical application in the recognition and separation of antibiotics. A novel magnetic surface molecularly imprinted nanomaterial based onto attapulgite nanorod (MATP/MIPs) has been successfully prepared by precipitation polymerization, which exhibited fast adsorption kinetics and selective recognition ability toward targeted sulfamethazine (SMZ) from water, as well as good regeneration ability, making it possible for practical application in the recognition and separation of antibiotics. [ABSTRACT FROM AUTHOR]

A molecularly imprinted polymer based on silica modified FeO microsphere and ionic liquid was prepared for the adsorption and specific recognition of DNA. Water-compatible imidazolium ionic liquids were introduced on the surface of silica-coated FeO microsphere, then used as the adsorbents, againsting DNA from salmon testes (stDNA) by combining immobilized template and surface imprinting techniques. The imprinted polymer layers were grafted onto ionic liquid functionalized microspheres through sol-gel approach using N-3-(3-triethoxysilylpropyl)-3-aminopropyl imidazolium chloride and N-3-(3-triethoxysilylpropyl)-3-mexyl imidazolium chloride as the functional monomers, and tetraethoxysilane as the cross-linker. Because both imidazolium ionic liquid and DNA are soluble in water, it is mandatory to implement an imprinted process in an aqueous medium to well maintain the integrity of the conformation. Fourier transform infrared spectrometry, thermogravimetric analysis, transmission electron microscopy, X-ray diffraction and vibrating sample magnetometry were employed to characterize the materials. The nanomaterials with multiple imprinting sites and biocompatible cavities exhibit high specific adsorption capacity of DNA (162 mg·g) and excellent rebinding selectivity (imprinting factor up to 6.6) against non-imprinted molecules at pH value of 5.10. Moreover, it is feasible to strip DNA from the highly cross-linked polymer network by using aqueous NaCl (1.0 M). The nanomaterials are cap able of capturing DNA from calf whole blood, which might provide a viable tool for DNA preconcentration, separation and recognition. [ABSTRACT FROM AUTHOR]

Magnetic molecularly imprinted polymer nanoparticles for di-(2-ethylhexyl) phthalate were synthesized by surface imprinting technology with a sol-gel process and used for the selective and rapid adsorption and removal of di-(2-ethylhexyl) phthalate from aqueous solution. The prepared magnetic molecularly imprinted polymer nanoparticles were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and vibrating sample magnetometry. The adsorption of di-(2-ethylhexyl) phthalate onto the magnetic molecularly imprinted polymer was spontaneous and endothermic. The adsorption equilibrium was achieved within 1 h, the maximum adsorption capacity was 30.7 mg/g, and the adsorption process could be well described by Langmuir isotherm model and pseudo-second-order kinetic model. The magnetic molecularly imprinted polymer displayed a good adsorption selectivity for di-(2-ethylhexyl) phthalate with respect to dibutyl phthalate and di- n-octyl phthalate. The reusability of magnetic molecularly imprinted polymer was demonstrated for at least eight repeated cycles without significant loss in adsorption capacity. The adsorption efficiencies of the magnetic molecularly imprinted polymer toward di-(2-ethylhexyl) phthalate in real water samples were in the range of 98-100%. These results indicated that the prepared adsorbent could be used as an efficient and cost-effective material for the removal of di-(2-ethylhexyl) phthalate from environmental water samples. [ABSTRACT FROM AUTHOR]

A novel core-shell structured composite of Fe 3 O 4 nanoparticles and molecularly imprinted polymers (MIPs), namely, magnetic MIPs (M-MIPs), was synthesized by surface imprinting technique combined with precipitation polymerization for the selective and sensitive fluorescent detection of 17β-estradiol (17β-E 2 ) based on the competitive desorption of fluorescein as a fluorescent indicator from the M-MIPs. The resulting M-MIPs were well characterized, and they showed ideal spherical morphology and magnetic property. Competitive rebinding of 17β-E 2 to the corresponding recognition sites regulated the release of fluorescein and resulted in an enhanced fluorescence signal. The fluorescence increase linearly coincided with the concentration of 17β-E 2 within the range of 0.10–70 μM with a detection limit of 0.03 μM. The recovery of 17β-E 2 from spiked lake and river water samples ranged from 98.2 to 103.8% with relative standard deviations between 1.1 and 3.8%. This study successfully integrated surface imprinting, competitive adsorption, magnetic separation and fluorescent detection, and also demonstrated fast binding kinetics, easy separation and reusability, and sensitive determination of template molecules. Thus, the M-MIP-based method may provide a simple, rapid, convenient, cost-effective and environmentally friendly way for the highly selective and sensitive recognition and detection of non-fluorescent molecules at trace levels. [ABSTRACT FROM AUTHOR]

[Display omitted] • Molecularly imprinted PANI was immobilized on Fe 3 O 4 /ZnO by surface imprinting technique. • The Fe 3 O 4 /ZnO@MI-PANI displayed selective photodegradation activity towards amoxycillin. • Fe 3 O 4 /ZnO@MI-PANI displayed better photocatalytic efficiency than Fe 3 O 4 /ZnO@NI-PANI. • The presence of Fe 3 O 4 enhanced visible light harvesting ability. In the present study, molecularly imprinted polyaniline was immobilized on Fe 3 O 4 /ZnO composite by surface imprinting technique. The obtained molecularly imprinted photocatalyst was used for selective degradation of amoxycillin under visible light irradiation. The presence of Fe 3 O 4 not only endowed the photocatalyst with magnetic separation feature but also enhanced visible light harvesting ability. Compared with Fe 3 O 4 /ZnO composite, photocatalytic performance of the molecularly imprinted photocatalyst was significantly improved because polyaniline could form a heterojunction with ZnO to enhance photocatalytic performance. The molecularly imprinted photocatalyst displayed better photocatalytic efficiency and selective photodegradation activity towards amoxycillin than the non-imprinted photocatalyst, because the photodegradation reaction could take place not only on surface of the photocatalyst but also in imprinted cavities for the molecularly imprinted photocatalyst, while the photodegradation only occurred on surface of the non-imprinted photocatalyst. Active species capture experiments showed that.O 2- and h+ played a crucial role in the degradation of amoxycillin. The current research provided new insight for fabrication of molecularly imprinted photocatalyst with selective degradation ability for organic pollutants. [ABSTRACT FROM AUTHOR]

Novel magnetic molecularly imprinted polymer nanoparticles (MMIPs) were synthesized by surface imprinting technology with a sol-gel process, using di(2-ethylhexyl)phthalate (DEHP) as the template. The MMIPs were characterized using Fourier transform-infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). The MMIPs displayed good adsorption selectivity for DEHP, with selectivity coefficients of 5.2 and 4.8 with respect to di- n-octyl phthalate and dibutyl phthalate, respectively. The reusability of MMIPs was demonstrated for at least eight repeated cycles without significant loss in adsorption capacity. A novel method for selective preconcentration and determination of trace DEHP in aqueous solutions was developed by using the magnetic DEHP-imprinted nanoparticles as adsorbent for solid-phase extraction (SPE) coupled with gas chromatography-mass spectrometry (GC-MS). The optimum SPE conditions were as follows: adsorbent amount, 50 mg; sample volume, 100 mL; adsorption time, 20 min; eluent, chloroform; and desorption time, 5 min. Results showed that the limit of detection (LOD) and limit of quantification (LOQ) for DEHP were 0.02 and 0.075 μg L, respectively. The proposed method was applied to the determination of DEHP in different real water samples, with spiked recovery of 93.3-103.2 % and RSD of 1.2-3.2 %. Therefore, the developed analytical method is rapid, sensitive, and accurate, which provides a new option for the detection of trace DEHP in aqueous samples. [ABSTRACT FROM AUTHOR]

In this work, novel magnetic molecularly imprinted polymers were prepared for the selective extraction of osthole from Libanotis Buchtomensis herbal extract. During the synthesis process, double bonds grafted on the surface of Fe3O4 nanoparticles could not only drive the temple molecules to locate onto the surface of vinyl-functionalized magnetic nanoparticles by π-π conjugation, which makes the distribution of binding sites ordered, but also direct the occurrence of imprinting polymerization at the surface of magnetic nanoparticles by the copolymerization of vinyl terminal groups with functional monomers and cross-linking agent. The characteristics of the resulting polymers were evaluated by transmission electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and vibrating sample magnetometry. Adsorption kinetics, isotherms, selectivity, reproducibility, and reusability were discussed, which suggest that the obtained nanomaterials possess rapid binding kinetics, high adsorption capacity of 17.65 mg/g, and favorable selectivity for the target molecule. Satisfactory reproducibility and reusability were verified as well. Meanwhile, the resultant imprinted nanoparticles were successfully applied to selectively separate osthole from the herbal extract, which show great potential in extracting active ingredients from traditional Chinese medicine. [ABSTRACT FROM AUTHOR]

Glycoproteins are crucial in massive physiological events and clinical application. It is necessary to prepare new materials to isolate the specific glycoprotein. New and simple core-shell molecularly imprinted polymers were prepared by surface imprinting. The polymers are synthesized with magnetic nanoparticles as the core, water-soluble dendritic polyethyleneimine as the monomer and the ovalbumin as the template. The prepared imprinted polymers showed thin imprinted shell, biocompatibility and superparamagnetic properties. The resultant materials exhibited fast kinetics, high adsorption capacity, perfect selectivity and reusability. More important, they can absorb the template glycoprotein from the neutral solution and successfully be applied to recognize the ovalbumin from egg white, which means that they can provide an alternate method to isolate glycoprotein from bodily fluids. [ABSTRACT FROM AUTHOR]

Bovine hemoglobin (BHb), as one of the high-abundance proteins, could seriously mask and hamper the analysis of low-abundance proteins in serum. To selectively deplete BHb, we design a simple and effective strategy for preparation of biocompatible molecularly imprinted shell on superparamagnetic iron oxide nanoparticles through surface imprinting technique combined with template immobilization strategy. Firstly, template proteins are immobilized on the directly aldehyde-functionalized magnetic nanoparticles through imine bonds. Then, with gelatin as functional monomer, a polymeric network molded around the immobilized template proteins is obtained. Finally, the specific cavities for BHb are fabricated after removing the template proteins. The effects of imprinting conditions were investigated and the optimal imprinting conditions are found to be 40 mg of BHb, 150 mg of gelatin, and 8 h of polymerization time. The resultant materials exhibit good dispersion, high crystallinity, and satisfactory superparamagnetic property with a high saturation magnetization (33.43 emu g −1 ). The adsorption experiments show that the imprinted nanomaterials have high adsorption capacity of 93.1 mg g −1 , fast equilibrium time of 35 min, and satisfactory selectivity for target protein. Meanwhile, the obtained polymers could be used without obvious deterioration after six adsorption-desorption cycles. In addition, the resultant polymers are successfully applied in the selective isolation BHb from bovine blood sample, which could provide an alternative solution for the preparatory work of proteomics. [ABSTRACT FROM AUTHOR]

A facile strategy to prepare the core–shell magnetic imprinted nanoparticles for specific recognition of protein is presented. The core is carboxyl-modified Fe 3 O 4 nanoparticles (Fe 3 O 4 @COOH) synthesized directly through a simple one-pot hydrothermal method. The formation of imprinted shell with specific recognition cavities includes three steps. Initially, the protein template is non-covalently anchored on Fe 3 O 4 @COOH. Next, the chemical oxidation of 3-aminophenylboronic acid takes place on the surface of Fe 3 O 4 @COOH-protein complex for further immobilization of template protein. Then, a thin imprinted layer is obtained on Fe 3 O 4 @COOH after the removal of the template protein. The resultant imprinted materials not only exhibit good dispersibility, uniform surface morphology, super-paramagnetic property, but also possess fast kinetics, high capacity, as well as favorable selectivity. In addition, the as-synthesized polymers could be used for six cycles of adsorption–desorption without obvious deterioration and applied to specifically separate and enrich target protein from real biological sample successfully. Furthermore, the result of versatility indicates that the facile preparation method is more suitable for basic proteins. [ABSTRACT FROM AUTHOR]

Novel core-shell dual-template molecularly imprinted superparamagnetic nanoparticles were synthesized using bovine hemoglobin and bovine serum albumin as the templates for the efficient depletion of these two high-abundance proteins from blood plasma for the first time. The preparation process combined surface imprinting technique and a two-step immobilized template strategy. The obtained polymers were fully characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and vibrating sample magnetometry. The results showed that the as-synthesized nanomaterials possessed homogeneous and thin imprinted shells with a thickness of about 5 nm, stable crystalline phase, and superparamagnetism. The binding performance of the imprinted polymers was investigated through a series of adsorption experiments, which indicated that the products had satisfactory recognition ability for bovine hemoglobin and bovine serum albumin. The resultant nanoparticles were also successfully applied to simultaneously selective removal of two proteins from a real bovine blood sample. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fibrous, porous, and magnetic imprinted strategies were combined in MPCM@MINs. • MPCM@MINs can be used as a novel adsorbent for Brilliant Blue extraction. • MPCM@MINs showed excellent properties of selectivity, fast separation, and reuse. • BB can be highly-efficient extraction and detection using MPCM@MINs with Uv. In this study, magnetic porous carbon microsphere composed of molecularly imprinted nanofibers (MPCM@MINs) were constructed and used as an adsorbent for the highly efficient extraction of Brilliant Blue (BB) in food samples. The MPCM@MINs contained imprinted nanofibers and a three-dimensional hierarchical porous structure with a magnetic responsive ability, resulting in a high surface area (368.3 m2·g−1), low mass-transfer resistance, large adsorption capacity, and fast separation ability. The maximum adsorption capacity of MPCM@MINs for BB was 39.47 mg·g−1 with excellent selectivity and a high imprinting factor (6.12). Moreover, MPCM@MINs exhibited good anti-interference ability, reusability and reliability. Importantly, BB can be easily and rapidly detected in food samples using MPCM@MINs as an adsorbent followed with UV–Vis method, and the relative standard deviation was lower than 5.85%. Therefore, MPCM@MINs may be a promising adsorbent for pollutant extraction in food samples due to the combination of different strategies of nanofibrous imprinting, magnetic separation, and hierarchical porous structure. [ABSTRACT FROM AUTHOR]

Abstract: Molecular imprinting is an attractive technique for preparing mimics of natural, biological receptors. Nevertheless, the imprinting of macromolecule remains a challenge due to their bulkiness and sensitivity to denaturation. In this work, we presented a method for preparing multifunctional lysozyme-imprinted nanoparticles (magnetic susceptibility, molecular recognition and environmental response). The magnetic susceptibility was imparted through the successful encapsulation of Fe3O4 nanoparticles. Selective lysozyme recognition depended on molecularly imprinted film. Moreover, it was also a hydrophilic stimuli-responsive polymer, which could undergo a reversible change of imprinted cavity in response to a small change in the environmental conditions. Thus, magnetic molecularly imprinted nanoparticles had high adsorption capacity (0.11mgmg−1), controlled selectivity and direct magnetic separation (22.1emug−1) in crude samples. After preconcentration and purification with magnetic MIPs nanoparticles, a sensitive chemiluminescence method was developed for determination of lysozyme in human serum samples. The results indicated that the spiked recoveries were changed from 92.5 to 113.7%, and the RSD was lower than 11.8%. [ABSTRACT FROM AUTHOR]

• CDs uniformly distributed into MIPs layers of MF-MIPs sensor. • The imprinted sites of MF-MIPs sensor exhibited a dual recognition capability. • MF-MIPs sensor showed excellent selectivity, sensitivity, rapidity, and reuse. • MF-MIPs sensor can detect trace 4-NP with accuracy, reliability and practicality. In this study, surface imprinting, magnetic separation, and fluorescent detection were integrated to develop a dual-recognition sensor (MF-MIPs), which was used for highly selective and sensitive detection of 4-nitrophenol (4-NP) in food samples. Silane-functionalized carbon dots (Si-CDs) participated in the imprinting process and were uniformly distributed into the MIPs layers. MF-MIPs sensor exhibited a high fluorescence response and selectivity based on the dual-recognition mechanism of imprinting recognition and fluorescence identification. The relative fluorescence intensity of MF-MIPs sensor presented a good linear relationship in the range of 0.08–10 μmol·L−1 with a low limit of detection (23.45 nmol·L1) for 4NP. MF-MIPs sensor showed high anti-interference, as well as excellent stability and reusability. The 4-NP recovery from spiked food samples ranged from 93.20 to 102.15%, and the relative standard deviation was lower than 5.0%. Therefore, MF-MIPs sensor may be a promising method for 4-NP detection in food samples. [ABSTRACT FROM AUTHOR]