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The current work describes the efficient creation and employment of a new S-citalopram selective polymeric sorbent, made from poly(divinylbenzene-maleic anhydride-styrene). The process began by using suspension polymerization technique in the synthesis of poly(styrene-maleic anhydride-divinylbenzene) microparticles. These were then modified with ethylenediamine, developing an amido-succinic acid-based polymer derivative. The S-citalopram, a cationic molecule, was loaded onto these developed anionic polymer particles. Subsequently, the particles were post-crosslinked using glyoxal, which reacts with the amino group residues of ethylenediamine. S-citalopram was extracted from this matrix using an acidic solution, which also left behind stereo-selective cavities in the S-citalopram imprinted polymer, allowing for the selective re-adsorption of S-citalopram. The attributes of the polymer were examined through methods such as 13 C NMR, FTIR, thermogravemetric and elemental analyses. SEM was used to observe the shapes and structures of the particles. The imprinted polymers demonstrated a significant ability to adsorb S-citalopram, achieving a capacity of 878 mmol/g at a preferred pH level of 8. It proved efficient in separating enantiomers of (±)-citalopram via column methods, achieving an enantiomeric purity of 97 % for R-citalopram upon introduction and 92 % for S-citalopram upon release., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

One of the gut-derived uremic toxins 4-ethylphenyl sulfate (4-EPS) exhibits significantly elevated plasma levels in chronic kidney diseases and autism, and its early quantification in bodily fluids is important. Therefore, the development of rapid and sensitive technologies for 4-EPS detection is of significant importance for clinical diagnosis. In the current work, the synthesis of a molecularly imprinted biopolymer (MIBP) carrying 4-EPS specific cavities only using the biopolymer polydopamine (PDA) and molybdenum disulfide (MoS 2 ) nanosheets has been reported. The fabricated electrode was prepared using screen-printed carbon electrodes on a polyvinyl chloride substrate. The synthesized material was characterized using several techniques, and electrochemical studies were performed using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The DPV technique for the electrochemical sensing of 4-EPS using the fabricated sensor (PDA@MoS 2 -MIBP) determined a sensitivity of 0.012 μA/ng mL/cm 2 and a limit of detection of 30 ng/mL in a broad linear range of 1-2200 ng/mL. Also, the interferent study was performed to evaluate the selectivity of the fabricated sensor along with the control and stability study. Moreover, the performance of the sensor was evaluated in the spiked urine sample, and a comparison was made with the data obtained by ultraperformance liquid chromatography-tandem mass spectroscopy.

Molecularly imprinted polymers (MIPs) are established artificial molecular recognition platforms with tailored selectivity towards a target molecule, whose synthesis and functionality are highly influenced by the nature of the solvent employed in their synthesis. Steps towards the "greenification" of molecular imprinting technology (MIT) has already been initiated by the elaboration of green MIT principles; developing MIPs in a solvent-free environment may not only offer an eco-friendly alternative, but could also significantly influence the affinity and expected selectivity of the resulting binding sites. In the current study the first solvent-free mechanochemical synthesis of MIPs via liquid-assisted grinding (LAG) is reported. The successful synthesis of the imprinted polymer was functionally demonstrated by measuring its template rebinding capacity and the selectivity of the molecular recognition process in comparison with the ones obtained by the conventional, non-covalent molecular imprinting process in liquid media. The results demonstrated similar binding capacities towards the template molecule and superior chemoselectivity compared to the solution-based MIP synthesis method. The adoption of green chemistry principles with all their inherent advantages in the synthesis of MIPs may not only be able to alleviate the potential environmental and health concerns associated with their analytical (e.g., selective adsorbents) and biomedical (e.g., drug carriers or reservoirs) applications, but might also offer a conceptual change in molecular imprinting technology.

Molecular imprinting represents one of the most promising strategies to design artificial enzyme inhibitors. However, the study of molecularly imprinted enzyme inhibitors (MIEIs) remains at a primary stage. Advanced applications of MIEIs for cell regulation have rarely been explored. Using a solid-phase oriented imprinting strategy so as to leave the active site of the enzymes accessible, we synthesized two MIEIs that exhibit high specificity and potent inhibitory effects (inhibition constant at low nM range) towards trypsin and angiogenin. The trypsin MIEI inhibits trypsin activity, tryptic digestion-induced extracellular matrix lysis and cell membrane destruction, indicating its utility in the treatment of active trypsin-dependent cell injury. The angiogenin MIEI blocks cancer cell proliferation by suppressing the ribonuclease activity of angiogenin and decreasing the angiogenin level inside and outside HeLa cells. Our work demonstrates the versatility of MIEIs for both enzyme inhibition and cell fate manipulation, showing their great potential as therapeutic drugs in biomedicine., (© 2021 Wiley-VCH GmbH.)

Lime juice as the most commonly used natural source production can be characterized using determination of flavonoids contents such as hesperidin. So, development of analyzing methods for checking the quality and healthiness of lime juices is necessary. In this study, we aimed to set up a selective solid phase extraction method using dummy molecularly imprinting approach for extraction and separation of hesperidin in lime juice to check the quality of commercial lime juice products of Mashhad city market. The imprinted polymers were synthesized by hesperitin as dummy template due to the hesperitin solubility in the wide range of porogenic solvents. The specificity extent of synthesized polymers toward hesperidin was tested and optimum one was used as adsorbent in solid-phase extraction cartridge. The dummy molecularly imprinted polymer with high adsorption capacity for hesperidin (dissociation constant 0.12 μM) was successfully used for extraction and clean-up of hesperidin in the lime juice matrix prior to analysis by high-performance liquid chromatography. The analysis of hesperidin was done in the range of 0.312-50 μg/mL with detection limit of 0.05 μg/mL. This technique was successfully set up to remove the interfering compounds for analysis of hesperidin in commercial lime juice products., (© 2021 Wiley-VCH GmbH.)

A novel of magnetic dummy-template molecularly imprinted polymers (mag-MWCNTs-DMIPs) were prepared by surface molecular imprinting technique. The structure of polymers were characterized and the binding properties were assessed by adsorption experiments. The synthetic mag-MWCNTs-DMIPs exhibit satisfying adsorption capacity, excellent selectivity and fast adsorption rate toward phenoxy carboxylic acid (PCA) herbicides. Afterwards, a reliable analytical method for selective separation and determination of trace PCA herbicides in cereals was established by using magnetic solid-phase extraction (mag-MWCNTs-DMIPs as magnetic adsorbent) and UPLC-MS/MS detection. A series of requisite factors were optimized in detail to achieve expected extraction performance. Under the optimum MSPE parameters, the mean spiked recoveries for analytes in different cereals ranged from 86.7% to 95.2% with intra- and inter-day precision not greater than 8.5% and 10.6%, respectively. At last, the developed method was successfully utilized for determination the four PCA herbicides in actual cereals., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A magnetic hydrophilic molecularly imprinted material (MIM) with multiple stimuli-responses was prepared for efficient recognition of bisphenol A (BPA). MIM consisted of a magnetic core, an inner silica dioxide shell and an outer hydrophilic polymer shell, responsive for rapid magnetic separation, protection of the magnetic core and pH-/thermo-sensitivity to BPA, respectively. Controlled adsorption and release of BPA by pH/temperature regulation were realized through the reversible components of poly[N-isopropylacrylamide-co-2-(dimethylamino)ethyl methacrylate (NIPAM-DMAEMA)] (PND). The resultant MIM possessed superior affinity, selectivity and kinetics to BPA in aqueous solution. MIM was successfully applied to detect BPA in beverages via dispersive solid-phase extraction (d-SPE) coupled with high performance liquid chromatography (HPLC), exhibiting satisfactory recoveries of 80.70-108.18% with relative standard deviations (RSD) below 6.08%. The limit of detection of BPA was obtained as low as 3.75 nmol/L. The versatile MIM could be a promising alternative for extraction/removal of BPA in complicated samples by multiple-stimuli regulations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A molecularly imprinted polymer for the selective determination of Di(2-ethylhexyl) phthalate (DEHP) in water was synthesized and evaluated. This was accomplished by the use of sodium methacrylate as the monomer, toluene as a porogen, ethylene glycol dimethacrylate as a crosslinker, azobisisobutyronitrile as initiator and DEHP as a template molecule to generate the selectivity of the polymer for the compound, as well as synthesizing non-imprinted polymers. Three different polymerization approaches were used, emulsion, bulk and co-precipitation, the polymers obtained by emulsion presented a high retention rate reaching 99%. The method was able to pre-concentrate DEHP in water samples up to 250 times. To evaluate the applicability of the method, concentrations in fortified and bottled water were assessed using our polymer and determining DEHP concentrations by gas chromatography with mass spectrometry. Reported concentrations in bottled water were 12.1 µg/L, well above reference values established by the U.S. Environmental Protection Agency.

A magnetic fluorescence probe was fabricated by coating carbon quantum dots-doped molecularly imprinted polymers (MIPs) layers on the surface of Fe 3 O 4 particles (MFMP) for detection of N-acyl homoserine lactones (AHLs) signaling molecules. N-Z-L-homoserine lactone molecular was used as the template to prepare AHLs MIP layers, employing MAA and HEMA as functional monomers. The developed MFMP owned superparamagnetism, fluorescence, fast response and class-selectivity. If AHLs (C 4 -HSL, C 6 -HSL, C 8 -HSL, C 10 -HSL, C 12 -HSL and C 14 -HSL) were captured by the MFMP, they quenched the fluorescence of the probe. Fluorescence dropped linearly in the concentration ranges of 3.65 × 10 -3  μmol/L-0.96 × 10 -1  μmol/L for AHLs. The MFMP was applied to the analysis of fish juice and milk samples, and recoveries ranged from 83.10% to 90.74% with relative standard deviation less than 5.1%. This study offered a novel strategy to fabricated AHLs fluorescence probe with great potential for wide-ranging application in agri-food products., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A novel method is successfully tested for non-covalent imprinting. Conditions are used which practically exclude the formation of prepolymerization complexes. The template is cholesterol, and no so-called functional monomer is used. The polymers contain only an acrylic diester crosslinker. The porogen isopropanol prevents even hydrogen bonding between the template and the monomer in the prepolymerization solution. Despite of these apparently very disadvantageous conditions, appreciable imprinting factors for cholesterol and imprinted selectivity against some other steroids are observed, similar to other cholesterol MIPs with proven analytical usefulness., Competing Interests: Declaration of competing interest The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Molecularly imprinted polymers (MIPs) are specific crosslinked polymers that exhibit binding sites for template molecules. MIPs have been developed in various application areas of biology and chemistry; however, MIPs have some problems, including an irregular material shape. In recent years, studies have been conducted to overcome this drawback, with the synthesis of uniform microsphere MIPs or molecularly imprinted microspheres (MIMs). The polymer microsphere is limited to a minimum size of 5 nm and a molecular weight of 10,000 Da. This review describes the methods used to produce MIMs, such as precipitation polymerisation, controlled/'Living' radical precipitation polymerisation (CRPP), Pickering emulsion polymerisation and suspension polymerisation. In addition, some green chemistry aspects and future perspectives will also be given.

Molecularly imprinted polymers coated magnetic particles (Fe 3 O 4 @MIPs) were prepared and used as adsorbents in solid phase extraction for efficient enantioseparation of racemic tryptophan (Trp) in aqueous medium. The amino-modified magnetic particles (Fe 3 O 4 -NH 2 ) were first synthesized by one-pot hydrothermal method. Then the template molecules (L-Trp) were assembled on the surface of Fe 3 O 4 -NH 2 . Finally, Fe 3 O 4 @MIPs were prepared via a sol-gel method using L-Trp@Fe 3 O 4 -NH 2 complex as matrix, 3-aminopropyltriethoxylsilane and n-octyltriethoxysilane as functional monomers. The as-prepared Fe 3 O 4 @MIPs were spherical with an average diameter about 149 ± 6.0 nm. The thickness of MIPs layer was approximately 3.5 ± 2.3 nm. The adsorption isotherms data of Fe 3 O 4 @MIPs toward L-Trp and D-Trp were well described by the Langmuir model. The maximum adsorption capacities of Fe 3 O 4 @MIPs for L-Trp and D-Trp were calculated to be 17.2 ± 0.34 mg/g and 7.2 ± 0.19 mg/g, respectively. The material exhibited good selectivity toward L-Trp with imprinting factor of 5.6. Excitingly, the enantiomeric excess (ee) of Trp in supernatant after adsorption of racemic Trp by Fe 3 O 4 @MIPs was as high as 100%. The result suggests that the imprinted caves in Fe 3 O 4 @MIPs are highly matched with L-Trp molecule in space structure and spatial arrangement of active functional groups. The work also demonstrates that sol-gel technology has great potential in preparation of MIPs for chiral separation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020. Published by Elsevier B.V.)

The present work reported a novel hydrophilic and selective solid-phase microextraction fiber by improved multiple co-polymerization method immobilization of tetracycline molecularly imprinted polymer on a stainless steel wire and directly coupled with high-performance liquid chromatography for sensitive determination of trace tetracyclines residues in animal derived foods. The developed molecularly imprinted polymer coated solid-phase microextraction fibers were characterized through scanning electron microscopy, Fourier transfer infrared spectroscopy, thermogravimetric analysis, and adsorption experiments, the fiber with cross-linked and porous structure was observed and high thermal and chemical stability. The maximum adsorption capacity of this fiber with good selectivity reached 2.35 µg/mg in aqueous matrices, and showed good repeatability (relative standard deviation ≤ 6.6%, n = 5) and satisfying reproducibility between fiber to fiber (relative standard deviation ≤ 7.8%, n = 5). Under the optimized solid-phase microextraction conditions, satisfactory linearity (5-1000 µg/L) and detection limits (0.38-0.72 µg/kg, S/N = 3) for all the tetracyclines were obtained. The practicality of this method was proved by adding tetracycline, oxytetracycline at three levels to milk, chicken, and fish samples with good recoveries of 77.3-104.4%., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

This study presents the development of a cholesterol-selective adsorbent that can be easily produced for the highly efficient removal of cholesterol from milk. A fundamental affinity separation technology which was combined with the specific recognition property of molecular imprinting with a high flow rate and the resulting cryogel was used to separate cholesterol separation from milk samples. The proposed material offers a reasonable pore size and structure, high surface area, and mechanical and chemical stability. To separation the cholesterol from milk, poly(2-hyroxyethyl methacrylate-N-methacryloyl-l-tryptophan methylester) cryogel beads were prepared using a functional monomer that allowed the formation of cholesterol-selective binding sites and enhanced the selective removal of cholesterol from milk. Characterization studies of the cholesterol-imprinted cryogel beads (CHO-MIPs) were carried out by attenuated total reflectance-Fourier transform infrared spectroscopy, scanning electron microscopy, elemental analysis, water-uptake tests and surface area measurements. The interactions between CHO-MIP and cholesterol were investigated and the factors affecting the adsorption of cholesterol were determined to find optimum conditions. Reusability as a measure of the continuity of the prepared CHO-MIPs was also investigated. The selectivity of the CHO-MIP beads was determined by using competing molecules (estradiol and progesterone), which are cholesterol analogues. The experimental data showed that the specific areas of the CHO-MIP and non-imprinted (NIP) cryogel beads were 17.6 and 14.7 m 2 /g, respectively. The CHO-MIP cryogel beads were 4.77 and 2.76 fold more selective for cholesterol compared to estradiol and progesterone respectively. The cholesterol adsorption capacity of the CHO-MIP beads was 288.72 mg/g when the cholesterol concentration in solution was 3.0 mg/mL. After eight adsorption-desorption cycles, the adsorption capacity of the CHO-MIP beads decreased by 9.21 %. The Langmuir-Freundlich isotherm model was well fitted as compare to Langmuir and Freundlich isotherms. The obtained kinetics data showed that a pseudo-second order mechanism was predominant for the CHO-MIP cryogel bead adsorption., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020. Published by Elsevier B.V.)

Glycoproteins are involved in the pathogenesis and development of many diseases and are used as biomarkers for disease diagnosis. It is highly desirable to develop highly sensitive and selective methods for the detection of glycoproteins without the use of antibodies. Imprinting of proteins represents one of the most challenging tasks. Glycoprotein imprinted self-assembled monolayers (SAMs) were created, for the first time, from an oligo(ethylene glycol) (OEG) terminated 1,2-dithiolane derivative linked through an alkyl chain incorporated with two amide groups (DHAP) and combined functional thiols of p-mercaptophenylboronic acid (PMBA) and p-aminothiophenol (PATP) in aqueous media, without the use of polymerization initiators. Combined action of PMBA and PATP was essential for the development of boronate recognition sites for glycoproteins at the physiological pH, attributed to the water molecule-mediated Lewis acid-base interactions between the electron-deficient PMBA and the electron-rich PATP. DHAP played key roles not only in cementation of imprinted cavities by means of double hydrogen bond networks through the amide groups but also in resistance to nonspecific protein binding by terminal OEG moieties, as well as hydrogen bond binding sites from the amide groups exposed to imprinted cavities. The created glycoprotein imprinted SAMs showed excellent recognition selectivity of target glycoproteins. The strategy for tailor-made glycoprotein imprinted SAMs explores a new avenue to the creation of intelligent biomaterials and fabrication of chemosensors.

In this study, a double-recognized aptamer-molecularly imprinted monolithic column (Apt-MIP monolithic column) was prepared by introducing both aptamer and MIP to reduce non-specific adsorption. Its preparation parameters such as the time of photo-initiation, the dosage of photo-initiator and the concentration of aptamer were investigated in detail. The recovery ratios of ochratoxin A (OTA) to ochratoxin B (OTB) on Apt-MIP monolithic column, Apt monolithic column and MIP monolithic column were 116.1, 40.8 and 69, respectively. Even if the concentration of OTB was 10 times that of OTA, the recovery of OTB was only about 2.9%. Applied to beer samples, the prepared Apt-MIP monolithic column drastically resisted background adsorption and the high-specificity recognition for OTA was obtained with the recoveries of 95.5-105.9%. This work provided a simple and effective method to selectively identify OTA from complex samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In this work, core/shell magnetic molecularly imprinted polymer nanoparticles were synthesized for extraction and pre-concentration of valsartan from different samples and then it was measured with high-performance liquid chromatography. For preparation of molecularly imprinted polymer nanoparticles, Fe 3 O 4 nanoparticles were coated with tetraethyl orthosilicate and then functionalized with 3-(trimethoxysilyl) propyl methacrylate. In the next step, molecularly imprinted polymer nanoparticles were synthesized under reflux and distillation conditions via polymerization of methacrylic acid, valsartan (as a template), azobisisobutyronitrile and ethylene glycol dimethacrylate as cross linking. The properties of molecularly imprinted polymer nanoparticle were investigated by FTIR spectroscopy, field emission scanning electron microscopy, and X-ray diffraction. Box-Behnken design with the aid of desirability function was used for optimizing the effect of variables such as the amounts of molecularly imprinted polymer nanoparticles, time of sonication, pH, and volume of methanol on the extraction percentage of valsartan. According to the obtained results, the affecting variables extraction condition were set as 10 mg of adsorbent, 16 min for sonication, pH = 5.5 and 0.6 mL methanol. The obtained linear response (r 2  > 0.995) was in the range of 0.005-10 µg/mL with detection limit 0.0012 µg/mLand extraction recovery was in the range of 92-95% with standard deviation less than 6% (n = 3)., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Fluorescent molecularly imprinted polymer (FMIP) optosensor was utilized for the selective identification of 2,4-dichlorophenoxacetic acid (2,4-D) due to worldwide pollution caused by using herbicides in agricultural industry. In this regards, two derivatives of polymerizable 1,8-naphthalimide namely, 1,8-naphthalimide containing thiourea (NI) and diethyl amine tagged 1,8-naphthalimide (NII) were used as the receptors and 2,4-D was applied as a template. Also, precipitation polymerization was applied to prepare the fluorescent molecularly imprinted polymer (FMIP). The morphological, structural and thermal analysis was carried out using SEM, TEM, EDS, BET, FTIR, DSC and TGA for characterizing the fluorescent optosensor. The adsorption efficiency of FMIP and FNIP was studied using Langmuir, Freundlich, BET and Redlich Peterson isotherms. The results represented that the adsorption of 2,4-D on FMIP and FNIP agreed the Freundlich adsorption isotherm with correlation coefficient of 0.9935 and 0.9801, respectively. The prepared sensor was able for the selective determination of 2,4-D salt in the linear range of 5 × 10 -7 -1 × 10 -3  M with a limit of detection of 16.8 nM. The present study revealed that the FMIP prepared by 1,8-naphthalimide derivative (NI) could potentially recognize the trace concentration of 2,4-D. Graphical Abstract Graphical abstract of flourescene switching mechanism in a fluorescent molecularly imprinted polymer sensor.

This paper describes the synthesis of a molecularly imprinted polymer by chemical oxidation of pyrrole as the functional monomer, and at the presence of guaifenesin as the template. The prepared polymer was used as adsorbent in molecularly imprinted solid-phase extraction followed by spectrophotometric determination. Different parameters in the solid-phase extraction including sample pH, adsorbent weight, washing solution, and elution solvent were studied to determine optimum conditions for isolation and enrichment of guaifenesin. The results showed guaifenesin was quantitatively adsorbed on the molecularly imprinted polymer at pH 6.0 and completely eluted with an ethanol-water solution (50% v/v). An enrichment factor of four with satisfactory recoveries (87.0-95.0%) was obtained. The solid-phase extraction columns could be used for up to six consecutive elution-loading cycles without significant decreases in the analyte recoveries. The method had a dynamic range of 3.0 × 10 -6 -1.5 × 10 -4  mol/L with a limit of detection and limit of quantification of 1.4×10 -6 and 4.5×10 -6  mol/L, respectively. The proposed procedure was used for the extraction and determination of guaifenesin in different pharmaceutical formulations, with satisfying results being achieved., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In this study, a new type of drug delivery carrier, the hollow magnetic silybin molecularly imprinted polymer (HMMIP) with a unique core-shell structure where the hollow magnetic core Fe 3 O 4 was wrapped by mesoporous silica and imprinted layer, was prepared from methacrylic acid (MAA, functional monomer), ethylene glycol dimethacrylate (EGDMA, cross-linker), and silybin (a drug template) by reverse atom radical transfer polymerization method (RATRP), and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometer (XRD), vibrating sample magnetometer (VSM), thermo-gravimetric analysis (TGA), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller analysis (BET). Its adsorption performance was evaluated by the isotherm/kinetic models and the selectivity for silybin with 15.40 mg g -1 of adsorption capacity and 2.13 of selectivity factor α, respectively. The drug release experiment showed the prepared polymer had the properties of silybin sustained release agent, because it could last to release silybin for 36 h in the medium of pH 2.0 at physiological temperature. In addition, the resuability experiment indicated the imprinted material had the good stability and reproducibility. So HMMIP should be of the potential value applied in drug delivery in the future., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Histone post-translational modification (PTM) is a marker for gene transcription and is involved in a range of cancers, such as breast cancer. Most importantly, different modifications of a specific site (e.g., mono-, di- and tri-methylations and acetylation at a lysine residue) are individually enriched in particular regions of the genome, indicating that they may serve distinct functions. How these patterns are built and whether downstream events are dependent on the precise site-specific modification status are still poorly understood. One of the prerequisites is to obtain quantitative information on individual modification forms. Currently, the low abundance of these forms creates a great challenge. In this study, a targeted proteomics assay based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) coupled with single template oriented molecularly imprinted polymers (MIPs) was developed to attempt to simultaneously quantify site-specific histone mono-, di- and tri-methylated and acetylated forms. Surrogate peptides, including an unmodified one, were selected as targets in both MIP enrichment and subsequent LC-MS/MS detection. As a consequence, a limit of quantification (LOQ) of ∼0.5 nM was achieved, which was 10-fold more sensitive than without MIPs and much more sensitive than mass spectrometry involving a scanning mode. Finally, the assay was employed to quantitatively analyze the H3K79, H3K122 and H4K31 modification status in human breast cell lines.

This investigation describes an integrated workflow for the parallel extraction and recovery of polyphenols and phytosterols from Pinot noir grape seeds. Using (E)-resveratrol and stigmasterol as exemplars, the approach employs two different molecular imprinted polymers in tandem for the extraction of these compounds and their subsequent analysis by capillary high-performance liquid chromatography (capHPLC) interfaced with electrospray ionisation tandem mass spectrometry (ESI MS/MS). Information on the selectivity of the solid-phase extraction processes was obtained through analysis of the binding behaviour of (E)-resveratrol- and stigmasterol-imprinted polymers using structurally similar polyphenols or phytosterols with the extent of binding determined from the capHPLC-ion trap ESI MS/MS data. This study documents with Pinot noir grape seed extracts and optimised solid-phase extraction protocols that the (E)-resveratrol-templated MIP enabled a very high recovery (99%) of the health-beneficial polyphenol (E)-resveratrol with co-purification of procyanidin and catechin/epicatechin. Further, the stigmasteryl-3-O-methacrylate-templated polymer resulted in high recovery (96%) of the phytosterol stigmasterol with co-purification of campesteryl glycoside. The results also demonstrate that rapid and high-resolution capHPLC-ESI MS/MS methods can be used as part of the work flow for selectivity optimisation and monitoring of the performance of MIPs intended for use in the solid-phase extraction of bioactive molecules with nutraceutical properties from agricultural waste streams., (Copyright © 2019 Elsevier B.V. All rights reserved.)

A novel dummy molecularly imprinted polymers (DMIPs) for aminoglycoside antibiotics (AAs) was prepared for the first time by precipitation polymerization using raffinose as template molecule, methacrylic acid as functional monomer and trimethylolpropane triacrylate as cross-linker. The obtained DMIPs were characterized in detail, and their adsorbing and recognition performance were evaluated. The results showed that the DMIPs exhibited specific recognition towards six AAs with large adsorption capacity. The dummy molecularly imprinted solid phase extraction (DMISPE) conditions including elution/washing solutions and sample loading volumes were optimized. Under optimum conditions, a convenient and efficient method for the determination of AAs in environmental water samples based on DMISPE coupling with hydrophilic interaction-high performance liquid chromatography-tandem mass spectrometry was established. The developed method showed good linearity with correlation coefficients higher than 0.9921 for all the analytes and good recoveries (70.8-108.3%) with relative standard deviations from 2.6 to 11.4% spiked at three different concentration levels in water samples. The limit of detection (S/N = 3) ranged from 0.006 to 0.6 ng/mL. The results demonstrated good potential of DMIPs for sample pretreatment of trace AAs in environmental water samples., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Recently, enormous attention has been focused on the development of protein-molecularly imprinted polymers (MIPs). In this sense, bovine serum albumin (BSA) is well regarded as a favorite template in various MIPs-based biochemical/analytical assays mainly due to its low price, easy availability, and high structural homology to human serum albumin (HSA). Equally, the implications of BSA in the pathology of different human-related disorders necessitate the development of methods for its precise detection in biological samples. Accordingly, the current review seeks to provide an update on the design, synthesis, and characterization of the developed MIPs which have used BSA as template protein. Also, the recognition and quantification of BSA in different real samples using the prepared MIPs are discussed. Additionally, main strategies, such as surface imprinting, epitope-MIPs, microcontact imprinting and other methods to overcome the problems associated with the molecular printing of BSA are discussed here. The final discussion provides a comparative exploration of different approaches developed, emphasizing their relative advantages and disadvantages and underlining developments and possible future directions., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In this study, we have developed a method to assess adenosine 5'-triphosphate by adsorptive extraction using surface adenosine 5'-triphosphate-imprinted polymer over polystyrene nanoparticles (412 ± 16 nm) for selective recognition/separation from urine. Molecularly imprinted polymer was synthesized by emulsion copolymerization reaction using adenosine 5'-triphosphate as a template, functional monomers (methacrylic acid, N-isopropyl acrylamide, and dimethylamino ethylmethacrylate) and a crosslinker, methylenebisacrylamide. The binding capacities of imprinted and non-imprinted polymers were measured using high-performance liquid chromatography with UV detection with a detection limit of 1.6 ± 0.02 µM of adenosine 5'-triphosphate in the urine. High binding affinity (Q MIP , 42.65 µmol/g), and high selectivity and specificity to adenosine 5'-triphosphate compared to other competitive nucleotides including adenosine 5'-diphosphate, adenosine 5'-monophosphate, and analogs such as adenosine, adenine, uridine, uric acid, and creatinine were observed. The imprinting efficiency of imprinted polymer is 2.11 for urine (Q MIP , 100.3 µmol/g) and 2.51 for synthetic urine (Q MIP , 48.5 µmol/g). The extraction protocol was successfully applied to the direct extraction of adenosine 5'-triphosphate from spiked human urine indicating that this synthesized molecularly imprinted polymer allowed adenosine 5'-triphosphate to be preconcentrated while simultaneously interfering compounds were removed from the matrix. These submicron imprinted polymers over nano polystyrene spheres have a potential in the pharmaceutical industries and clinical analysis applications., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A kind of molecularly imprinted polymers modified with biocompatible medium was prepared by suspension polymerization. The obtained hybrid materials were used as the adsorbents for the solid-phase extraction of aflatoxins B1 in real samples. A structural analog of the target, 6-methyl-4-phenylchroman-2-one was used as the pseudo-template, owing to their lower toxicity and cheaper price compared with aflatoxins B1; and methacrylic acid and glycidyl methacrylate were used as the co-monomers. Scanning electron microscopy and size distribution analysis were used to characterize the obtained polymers. The extraction parameters were optimized to achieve the desired extraction performance. The polymer solid-phase extraction coupled with high-performance liquid chromatography was successfully applied to determine aflatoxins B1 from soy sauce without the process of protein removal. Under the optimum extraction conditions, the detection results of aflatoxins B1 in lab-made column in soy sauce samples was carried out, with a recovery rate of 96%. The established method presented a linear range from 10 to 1000 ng/mL with the coefficient of determination of 0.9994 and the limit of detection of 0.05 ng/mL. Likewise, the inherent selectivity of lab-made column towards aflatoxins B1, Ochratoxin A, and Zearalenone was demonstrated., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

An electrochemical platform was proposed for highly sensitive and selective analysis of sialic acid based on molecularly imprinted polymers (MIPs), which were electropolymerized with the monomer molecules of 3-aminophenylboronic acid (ABA) on a carbon cloth (CC) electrode in the presence of template molecules. The fabricated sensor, named the PABA/CC-based MIP electrode, could be used for the detection of sialic acid because the reversible and covalent boronic acid-diol binding was sensitive to the electrochemical potential of the prepared sensor. The utilization of a CC film as the substrate could improve the sensitivity due to its good electrical conductivity and large surface area. Under the optimized conditions, a good relationship between the change in potential and the concentration of sialic acid was obtained in the range from 40 μM to 440 μM with a detection limit of 0.5 μM. The resulting MIP sensor also displayed good selectivity, reproducibility and stability. Moreover, this sensor was successfully applied for the evaluation of the sialic acid level in infant formulas.

A novel magnetic molecularly imprinted polymer adsorbing material was successfully synthesized to detect ribavirin in animal feedstuff. Molecularly imprinted polymer was prepared through surface polymerization by using ribavirin as template molecule, methyl methacrylate, and γ-methacryloxypropyl trimethoxy silane functionalized magnetic mesoporous silica as bifunctional monomers, and ethylene diglycidyl ether as crosslinking agent. The prepared magnetic molecularly imprinted polymer was characterized by scanning electron microscopy and infrared spectroscopy. Static and dynamic adsorption experiments and selective adsorption analysis were performed to evaluate the adsorption and selectivity of magnetic molecularly imprinted polymer. Different experiments were conducted to optimize the magnetic solid-phase extraction conditions. Under optimal experimental conditions, a magnetic molecularly imprinted solid-phase extraction coupled with high-performance liquid chromatography method was successfully developed for ribavirin detection. The established method achieved a satisfactory linear range of 0.20-50 mg/L (R 2  > 0.99) and a low detection limit (0.081 mg/kg). An average recovery of 92-105% with relative standard deviation of <6.5% was obtained upon the application of the developed method to detect ribavirin in real feedstuff samples. Thus, established method can be used for the rapid and simple separation and detection of added ribavirin in feedstuff., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In this work, a novel surface molecularly imprinted polymer with high adsorption capacity, high adsorption rate, and high selectivity for fluoroquinolones was prepared on the surface of UiO-66-NH 2 , which is a kind of metal-organic framework. The surface morphology and adsorption properties of this molecularly imprinted polymer were investigated. The maximum adsorption capacity was 99.19 mg/g, and adsorption equilibrium was achieved within 65 s. Combined with reversed-phase high-performance liquid chromatography, the molecularly imprinted polymer was used to selectively enrich, separate and analyze fluoroquinolones present in lake water. The results showed that the recoveries of the four fluoroquinolones were 92.6-100.5%, and the relative standard deviations were 2.9-6.4% (n = 3). The novel molecularly imprinted polymer is an excellent adsorbent and has broad application prospects in the enrichment and separation of trace analytes in complex samples., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In this work, the molecularly imprinted polymer was used as a selective sorbent in solid-phase extraction method for the spectrophotometric determination of nortriptyline at 239 nm. Molecularly imprinted polymer was synthesized by pyrrole as a functional monomer in the presence of nortriptyline as a template. Several factors, consist of the concentration of the monomer to template ratio, amount of initiator, stirring rate, reaction time, the pH of the buffer solution, amount of sorbent, loading time, shaking rate of loading, extraction time, and shaking rate of extraction were evaluated due to their effectiveness in the preparation and extraction capability of molecularly imprinted polymer. Multivariate optimization methods, such as Plackett-Burman and central composite designs, were employed to find and optimize the significant factors. Under the selected optimal conditions, molecularly imprinted polymer showed a linear range from 0.1 to 100 µmol/L (0.026 to 26 µg/mL) nortriptyline, a detection limit of 10.3 nmol/L (2.7 ng/mL), a highly repeatable (relative standard deviation of 3.7%) and reproducible response (relative standard deviation of 4.6%), and a good selectivity in the presence of structurally related molecules. Furthermore, molecularly imprinted polymer showed high extraction efficiency and was successfully used for the determination of nortriptyline in real samples., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Pyrrolizidine alkaloids are the most widely distributed natural toxins, and pyrrolizidine alkaloid-containing herbal medicines are probably the most common poisonous plants affecting humans. We reported pyrrolizidine alkaloid-molecularly imprinted polymer solid-phase microextraction for the selective adsorption of toxic pyrrolizidine alkaloids from herbal medicine. A sulfonic compound, sodium allylsulfonate, was chosen as the functional monomer to interact with pyrrolizidine alkaloids through strong ionic interaction. To avoid template leakage and for the aim of cost saving, a relatively cheap dummy template was used for the fabrication of molecularly imprinted polymer-solid-phase microextraction fibers. The obtained fibers showed selective adsorption ability for four pyrrolizidine alkaloids, including europine, echimidine, lasiocarpine, and heliotrine. The extraction parameters, such as extraction time, extraction temperature, shaking speed, elution solvent and elution time, were optimized. Then ultra high performance liquid chromatography with mass spectrometry coupled with molecularly imprinted polymer-solid-phase microextraction method was developed for the fast and efficient analysis of four pyrrolizidine alkaloids from the model herbal plant Farfarae Flos. The established method was validated and exhibited satisfactory accuracy and precision. The present method provides an innovative and fast analytical strategy for the determination of trace toxic pyrrolizidine alkaloids in complicated samples., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The purpose work is devoted to design of a simple, one-pot and green approach for the synthesis of molecularly imprinted polymer to construct a selective sorbent for pipette-tip solid phase extraction of Rhodamine B from chili powder samples and its subsequence separation and quantification by high performance liquid chromatography-ultraviolet/visible detection. The prepared molecularly imprinted polymer was synthesized using chitosan as versatile natural multi-functional bio-monomer and Rhodamine B as template in aqueous media. The effects of influential parameters (sorbent dosage, flow rate and eluent solvent volume) and their influences on Rhodamine B extraction recovery were examined and optimized by central composite design based response surface methodology as a powerful multivariate optimization tool. Under the optimized conditions, the linear range and limit of detection and quantification of proposed method were achieved to be 0.005-15 mg kg -1 , 0.0015 mg kg -1 and 0.00488 mg kg -1 , respectively, with satisfactory recoveries (>85.0%) and excellent repeatability (relative standard deviation < 6.1%). The easy synthesis conditions as well as satisfactory figures of merit are good indication of applicability of suggested method for extraction and determination of Rhodamine B from chili powder samples in terms of simplicity, cost effectiveness, selectivity and accurate analysis., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Potentiometric glutathione (GSH) sensors were fabricated using a molecularly imprinted polymer prepared from GSH, methacrylic acid (MAA), and ethylene glycol dimethacrylate as the template molecule, functional monomer, and cross-linker, respectively. Five GSH sensors were prepared with different ratios of GSH to MAA. Their potential responses were measured in a GSH aqueous solution using Ag/AgCl as the reference electrode. A GSH sensor prepared with a GSH:MAA ratio of 2:32 had the best responsivity, while the sensor synthesized from a non-imprinted polymer prepared without GSH (NIP sensor) showed a potential response value of almost zero after the addition of GSH. The ratio of the potential responses of the GSH sensor to the NIP sensor was 8.21. Additionally, the GSH sensor had good linearity over a GSH concentration range of 1 × 10 -5 to 2 × 10 -4 mol L -1 . The GSH sensor provided good quantification and high specificity for GSH and is expected to be applicable for easy and direct determinations of GSH.

In this work, we provided a novel strategy of antibody-free biomarker analysis by in-situ synthesized molecularly imprinted polymers (MIPs) on movable valve microfluidic paper-based electrochemical device (Bio-MIP-ePADs) for clinical detection of biomarkers. The newly movable valves on the device enable continuous and convenient delivery of fluid, which guarantee the performance for fabricating MIPs structure during long time electropolymerization. Moreover, this strategy can directly detect antigens by taking advantage of molecular imprinting on paper-based device, which greatly decreases the cost during clinical testing, reduces the tedious washing procedure and does not need to consider the preservation of the antibody in enzyme linked immunosorbent assay (ELISA). This feature makes the chip suitable for the on-site family treatment or commercial products. To further validate the applicability of this proposed method for clinical diagnostic testing, carcinoembryonic antigen (CEA) was applied as prototyping model target for the clinical analysis. The proposed Bio-MIP-ePADs were cheap, easy to prepare, disposable and provided reliable analysis by comparing with ELISA. We hope the application of this technology will open up a new avenue to the point-of-care testing (POCT)., (Copyright © 2019 Elsevier B.V. All rights reserved.)

One of the major drawbacks of conventional molecularly imprinted polymers (MIPs) is the requirements of volatility porogenic solvent during polymerization. To overcome the default, MIP based on deep eutectic solvent (DES, a new type of green designer solvents) has been synthesized successfully. To improve the affinity of the MIP based on DES, in this work, a strategy of metallic pivot was suggested in the first time to prepare a highly selective MIP monolithic column. A cetirizine-imprinted polymer was prepared in a DES-based porogen system composed of choline chloride/ ethylene glycol (ChCl-EG) in the presence of Co(Ac) 2 as metallic pivot. The resulting DES- Co 2+ -MIP monolith had 23.5 times higher imprinting factor than the Co 2+ -free MIP monolith. The characterization of polymers indicated that DES was one of the primary factor influencing the MIP morphology and pore structure. Compared with previous metal-mediated and ionic liquid-based imprinted polymers, the introduction of DES as a porogen in polymerization led to higher imprinting factor (approximately 2.9 - 17.1 times). In addition, the resulting DES-Co 2+ -MIP can be used as an adsorbent for extraction of cetirizine from ethanol solution with the recoveries of 97.8%. As a conclusion, the metallic pivot is a rather valuable strategy for the synthesis of DES-based MIP monolith with high selectivity., (Copyright © 2019 Elsevier B.V. All rights reserved.)

An electrochemical sensor for the opioid drug buprenorphine (BUP) is described. Molecularly imprinted polymer nanoparticles (nanoMIP) were prepared and used to modify a carbon paste electrode (CPE). The BUP-imprinted polymer was synthesized using precipitation polymerization. The resulting polymer along with multiwalled carbon nanotubes (MWCNT) was used to fabricate the modified CPE which exhibited an anodic peak at about +0.73 V (vs. Ag/AgCl) for BUP. The MIP on the CPE functions as selective recognition element with an imprinting factor of 5.6. The assay consists of two-steps, viz. analyte extraction at the electrode surface and differential pulse voltammetric determination of BUP. The effects of various parameters on the electrochemical signal were optimized, and the selectivity of the modified CPE over cross reactants was studied. At optimum experimental conditions, the response is linear in the 1 nM to 50 μM BUP concentration range, and the detection limit is 0.6 nM (at S/N = 3). This method was applied to the determination of BUP in spiked urine with acceptable relative standard deviations (3.2-4.4%). Graphical abstract Schematic representation of buprenorphine (BUP) recognition and voltammetric determination at the surface of carbon paste electrode modified with imprinted polymer and carbon nanotubes.

A visual, rapid, and sensitive method for the detection of two algal metabolites, geosmin (GSM) and 2-methylisoborneol (2-MIB) using a competitive displacement technique based on molecular imprinted polymers (MIPs) and fluorescent tags was developed. In this method, fluorescent tags that bind to synthetic receptor sites of MIPs were designed and synthesised. In the presence of target analytes (geosmin and 2-methylisoborneol respectively), the tags are displaced leading to fluorescence signals. The MIPs were derived from the polymerisation of functional monomers and crosslinkers in the presence of suitable templates. Good to high binding capacities and selectivities were obtained with the MIPs. The displacement of fluorescent-tagged substrates from the respective MIPs by the target analytes enabled the quantitative detection of geosmin at concentrations as low as 0.38 μM (69 μg L -1 ), while the LOD for 2-methylisoborneol is 0.29 μM (48 μg L -1 ) without any cross-reactivity, non-specific (false-positive) binding, and matrix complications. Qualitative detection of geosmin and 2-methylisoborneol is also possible via visualisation of fluorescence using a hand held UV lamp, with LOD for geosmin and 2-methylisoborneol at 0.44 μM (80 μg L -1 ) and 0.35 μM (60 μg L -1 ), respectively. The sensitivity of the system can be improved with a pre-concentration step using the respective MIPs as a sorbent., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In this work, a novel thermosensitive surface protein imprinted polymer monolithic column (TsIPMC) was synthesized by combining high internal phase emulsion with 1,1-diphenylethene (DPE) controlled polymerization. Innovatively, DPE and acrylic acid (AA) monomers were introduced in high internal oil and water phases respectively. The research showed that DPE could not only initiate the polymerization of monomers, but also improve the pore performance of monolithic columns. The elution efficiency of template or target protein could be significantly improved by the thermoresponse characteristics of TsIPMC. The effects of DPE and AA on adsorption capacity and imprinting factor (IF) were studied. The optimization results presented that the optimal addition amounts were 55 mg and 50 mg. Under such conditions, the IF of as-prepared TsIPMC was 1.61 and the saturated adsorption capacity was 66 mg/mL. The influences of the flow rate and target protein concentration on the adsorption equilibrium time and effluent volume were revealed. TsIPMC showed higher selectivity for different competing proteins. The reuse stability result showed that the adsorption of TsIPMC to BSA decreased by 3.69% after 12 times of reuse, and the IF remained basically unchanged. TsIPMC would demonstrate the potential applications in the field of protein purification and separation., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Magnetic molecularly imprinted polymers (M-MIPs) with core-shell structure were prepared through the surface molecular imprinting technique by using quercetin as the template molecule. The resultant Fe 3 O 4 @MIPs were characterized using X-ray diffraction, Fourier transform infrared spectrum, transmission electron microscopy, and vibrating sample magnetometer. The Fe 3 O 4 @MIPs possessed high adsorption capacity and specific recognition for quercetin. The maximum adsorption capacity of Fe 3 O 4 @MIPs towards quercetin was 10.52 mg/g, and could reach binding equilibrium within 30 min. The selectivity and specific recognition ability of Fe 3 O 4 @MIPs were evaluated according to their recognition to quercetin and its analogues. The Fe 3 O 4 @MIPs were successfully applied as selective sorbents to extract and determine quercetin from apple samples with a relatively high recoveries (89.2-93.6%) and relative standard deviations of <5%. The obtained Fe 3 O 4 @MIPs have potential application for quercetin determination in real samples., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Molecularly imprinted polymers (MIPs) have potential as alternatives to antibodies in the diagnosis and treatment of disease. However, atomistic level knowledge of the prepolymerization process is limited that would facilitate rational design of more efficient MIPs. Accordingly, we have investigated using computation and experiment the protein-monomer binding interactions that may influence the desired specificity. Myoglobin was used as the target protein and five different acrylamide-based monomers were considered. Protein binding sites were predicted using SiteMap and binding free energies of monomers at each site were calculated using MM-GBSA. Statistical thermodynamic analysis and study of atomistic interactions facilitated rationalization of monomer performance in MIP rebinding studies (% rebind; imprinting factors). CD spectroscopy was used to determine monomer effects on myoglobin secondary structure, with all monomers except the smallest monomer (acrylamide) causing significant changes. A complex interplay between different protein-monomer binding effects and MIP efficacy was observed. Validation of hypotheses for key binding features was achieved by rational selection of two different comonomer MIP combinations that produced experimental results in agreement with predictions. The comonomer studies revealed that uniform, noncompetitive binding of monomers around a target protein is favorable. This study represents a step toward future rational in silico design of MIPs for proteins.

This work demonstrates the synthesis and characterization of core-shell magnetic molecularly imprinted polymers based on surface imprinting using methacryloyl chloride as a functional monomer for the selective extraction of imidacloprid (template) from apple fruit. The characterization analysis results ensured the successful synthesis of the magnetic molecularly imprinted polymers owing to their heterogeneous structure and good magnetic properties. An isothermal binding test was assessed with a pseudo-second-order kinetic model, and the kinetic results fit well to the Freundlich isothermal model. The polymers exhibited an adsorption capacity of 5.75 mg/g for the target analyte with a good selective extraction ability. In addition, the polymers can be reused several times without significant performance loss. The molecularly imprinted polymers showed good performance in the analysis of spiked apple sample with a linear range of 0.05-1.0 mg/L, a limit of detection of 0.048 mg/L and a limit of quantification of 0.146 mg/L (S/N = 3/10). The recoveries of the samples were 77.66-96.57% and their respective relative standard deviations were 3.36-0.45%. All the results indicated that the proposed method provided good selective extraction, as qualifying the analytical standards., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In this study, an innovative analytical methodology capable of selectively identifying and quantifying mercury contamination by the association of solid-phase extraction using ion-imprinted polymers as a sorbent phase and differential pulse anodic stripping voltammetry is proposed. To this end, the ion-imprinted polymers were synthesized and characterized by infrared spectroscopy and atomic force microscopy. The sorption capacities and the selectivity of the ion-imprinted polymers were compared to the ones related to the non-imprinted ones. Next, the experimental parameters of this solid-phase extraction method (IIP-SPE) were evaluated univariately. The selectivity of this polymeric matrix against other cations (Cd II, Pb II, and Cu II) was also evaluated. Limits of detection (LOD) and quantification (LOQ) obtained for the here proposed methodology were 0.322 μg L -1 and 1.08 μg L -1 , respectively. Also, the precision of 4.0% was achieved. The method was finally applied to three water samples from different sources: for the Piratininga and Itaipu Lagoon waters, Hg II concentrations were below the LOQ and for Vargem River waters a concentration equal to 1.35 ± 0.07 mg L -1 was determined. These results were confirmed by recovery tests, resulting in a recovery of 96.2 ± 4.0%, and by comparison with flame atomic absorption spectrometry, resulting in statistical conformity between the two methods at 95% confidence level.

The objective of this article was to design the selective molecularly imprinted sorbent dedicated to the solid-phase extraction of S-pramipexole from the complex matrix such as human urine. For that purpose, S-2,6-diamino-4,5,6,7-tetrahydrobenzothiazole was used as the template acting as the structural analog of S-pramipexole and five various monomers were employed in the presence of ethylene glycol dimethacrylate to produce molecularly imprinted polymers. The binding capabilities of resulted polymers revealed that the highest imprinting effect was noted for polymer prepared from the itaconic acid. The comprehensive analysis of morphology and the characterization of binding sites showed not only negligible differences in the extension of surfaces of imprinted and nonimprinted polymers but also higher heterogeneity of binding sites in the imprinted material. Comprehensive optimization of the molecularly imprinted solid-phase extraction allowed to select the most appropriate solvents for loading, washing, and elution steps. Subsequent optimization of mass of sorbent and volumes of solvents allowed to achieve satisfactory total recoveries of S-pramipexole from the model multicomponent real sample of human urine that equals to 91.8 ± 3.2% for imprinted sorbent with comparison to only 37.1 ± 1.1% for Oasis MCX., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Removal of the heavy metal ions in aqueous solution is an important technology for waste water treatment. The effects of using ultrasonic and microwave on synthesizing Pb 2+ , Zn 2+ , and Cu 2+ imprinted mesoporous adsorbents (Pb-IMA-UM, Zn-IMA-UM, and Cu-IMA-UM) and their dynamic adsorption properties were studied. The microstructure and composition of the ion-imprinted mesoporous adsorbents were discussed in detail by TEM, FTIR, N 2 adsorption-desorption, XRD, and EDS. The pore sizes of mesoporous absorbents were improved more uniformly by using ultrasonic agitation than magnetic stirring. The elution efficiency of imprinting ions can be enhanced by microwave elution. Prepared Pb-IMA-UM, Zn-IMA-UM, and Cu-IMA-UM were used for dynamic adsorption study of heavy metals. The detected optimal feed rate was 20.0 mL/min and the influent concentration was 60 mg/L; the equilibrium adsorption capacities of Pb-IMA-UM, Cu-IMA-UM, and Zn-IMA-UM could reach 198 mg/g, 51.5 mg/g, and 57.3 mg/g, respectively. The dynamic regeneration performance of the adsorbent was also investigated with the Cu-IMA-UM sample. The adsorption rate remained above 89% after five dynamic regeneration experiments. At last, the actual wastewater from an electroplating industry was used as the research object. Three groups of dynamic adsorption coefficient contours of Pb-IMA-UM, Zn-IMA-UM, and Cu-IMA-UM were obtained when influents flowed into three adsorption columns separately. The experimental results showed that an ion-imprinted adsorbent had a much better adsorption capacity of imprinted ions under the various metals mixed conditions.

Apart from being a vital catecholamine molecule responsible for the proper functioning of the central nervous system (CNS), hormonal and renal systems, dopamine (DA) has also been increasingly employed as a functional monomer in the fabrication of surface molecular imprinting polymers (MIPs) for valuable analytes. Herein, we demonstrate the effective imprinting of 6-thioguanine (6-TG), an anticancer drug, via mussel-inspired self-polymerization of dopamine conducted in a weakly alkaline solution over reduced graphene oxide (rGO). The polymerization of 6-TG resulted into a thin polydopamine (PDA) film of 8.4 nm thickness. Removal of 6-TG molecules from this imprinted PDA film created numerous cavities of 6-TG. The electrochemical investigation of MIP electrodes found an excellent electrocatalytic activity toward 6-TG with a significant decrease in the over-potential as compared to that of the bare glassy carbon electrode (GCE). This can be attributed to the graphene's distinct physical and chemical features such as subtle electronic characteristics, an attractive π-π interaction as well as the strong adsorptive capability of MIP films. This electrochemical sensor displayed a high selectivity owing to the specific imprinted cavities for adrenaline and worked well over a wide linear concentration range of adrenaline between 0.0015 and 50 μM with a detection limit (LOD) of 0.25 nM and good reproducibility and stability. Our system depicts excellent recoveries from 97.0% to 100.6% for two different samples of urine and thioguanine drugs. These results show the great potential of our system with multiple advantages, including convenient fabrication and optimization, high sensitivity and selectivity, high reproducibility and stability, and cost-effectiveness.

In this study, a surface plasmon resonance (SPR) biosensor was developed for the detection and quantification of a secreted bacterial factor (RoxP) from skin. A molecular imprinting method was used for the preparation of sensor chips and five different monomer-cross-linker compositions were evaluated for sensitivity, selectivity, affinity, and kinetic measurements. The most promising molecularly imprinted polymer (MIP) was characterized by using scanning electron microscopy, atomic force microscopy, and cyclic voltammetry. Limit of detection (LOD) value was calculated as 0.23 nM with an affinity constant of 3.3 × 10 -9 M for the promising MIP. Besides being highly sensitive, the developed system was also very selective for the template protein RoxP, proven by the calculated selectivity coefficients. Finally, absolute concentrations of RoxP in several skin swabs were analyzed by using the developed MIP-SPR biosensor and compared to a competitive ELISA. Consequently, the developed system offers a very efficient tool for the detection and quantification of RoxP as an early indicator for some oxidative skin diseases especially when they are present in low-abundance levels (e.g., skin samples).

We describe the preparation and characterization of synthetic antibodies based on molecularly imprinted polymer nanoparticles (MIP-NPs) for the recognition and binding of the highly conserved and specific peptide motif SWSNKS (3S), an epitope of the envelope glycoprotein 41 (gp41) of human immunodeficiency virus type 1 (HIV-1). This motif is implicated in the decline of CD4 + T cells and leads to the deterioration of the immune system during HIV infection. Therefore, the development of MIP-NPs that can target and block the 3S peptide to prevent subsequent cascade interactions directed toward the killing of CD4 + T cells is of prime importance. Because most antibodies recognize their protein antigen via a conformational or structured epitope (as opposed to a linear epitope commonly used for molecular imprinting), we employed protein molecular modeling to design our template epitope so that it mimics the three-dimensional structure fold of 3S in gp41. The resulting template peptide corresponds to a cyclic structure composed of CGSWSNKSC, with the 3S motif well orientated for imprinting. MIP-NPs with a size of 65 nm were obtained by solid-phase synthesis and were water-soluble. They were prepared by a judicious combination of multiple functional monomers affording hydrogen bonding, ionic, π-π, and hydrophobic interactions, conferring high affinity and selectivity toward both the cyclic peptide and the whole gp41 protein. These results suggest that our MIPs could potentially be used for blocking the function of the 3S motif on the virus.

Hyaluronic acid (HA) is a glycosaminoglycan that plays many roles in health and disease and is a key biomarker of certain cancers. Therefore, its detection at an early stage, by histochemical methods, is of importance. However, intracellular HA can be masked by other HA-binding macromolecules, rendering its visualization somehow problematic. We show that fluorescent molecularly imprinted polymer nanogels (MIP-NPs), can localize and detect intracellular HA. MIP-NPs were synthesized by solid-phase synthesis on glass beads (GBs). GBs were functionalized with terminal alkyne groups on which an azide derivative of the template molecule glucuronic acid was immobilized via click chemistry. Immobilization via the anomeric carbon left the template's carboxyl moiety free to enable strong stoichiometric electrostatic interactions with a benzamidine-based functional monomer, to confer selective recognition to the MIP-NPs. Due to the two-point orientation of the template, the resulting MIP-NPs were endowed with improved binding site homogeneity and specificity, reminiscent of monoclonal antibodies. These synthetic antibodies were then applied for probing and staining HA, of which glucuronic acid is a substructure (epitope), on human epidermal cells. Their excellent sensitivity, small size and water compatibility, enabled the MIP-NPs to visualize HA, as evidenced by confocal fluorescence micrographs.

Herein, a selective and sensitive fluorescence sensor was developed for the detection of phenobarbital, an epilepsy drug, using molecularly imprinted polymers (MIPs) coated on the surface of green source carbon dots (GSCDs). First, GSCDs were synthesized through a hydrothermal method using Cedrus as a carbon source. Then, a MIPs-GSCDs as a fluorescence probe was obtained by coating a thin film of silica on the surface of the GSCDs using a reverse micro emulsion method. In this step, phenobarbital, 3-aminopropyltriethoxysilane (APTES) and tetraethoxysilane (TEOS) were applied as a template, a functional monomer, and cross linker, respectively. The fluorescence signal of MIPs-GSCDs was selectively quenched by phenobarbital rebinding with MIP cavities. The fluorescence quenching signal was applied for phenobarbital sensing at the pH = 8 without the interference of other materials. After optimizing the factors affecting the sensor's response, a linear range between 0.4 and 34.5 nmol L -1 with a detection limit of 0.1 nmol L -1 was obtained. The sensor's capability in the real sample analysis was investigated by phenobarbital determination in a human blood plasma samples., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The cystine-bridged cyclic peptide hormones (CBCPHs) represent signature structural feature as well as unique biological activity. In this study, three CBCPHs have been identified and characterized, namely, oxytocin, atrial natriuretic peptides (ANPs), and brain natriuretic peptides (BNPs). Because research has shown that ANPs and BNPs are powerful diagnostic biomarkers for heart disease, a highly laudable endeavor would be to develop a novel sensor for detecting ANP or BNP levels. Therefore, an amphiphilic monomer Acr-His-NHNH-Fmoc was synthesized to form molecularly imprinted polymers (MIPs) for targeted CBCPH detection. First, oxytocin, a cardiovascular hormone and a CBCPH, was used as a template to fabricate MIPs on quartz crystal microbalance (QCM) chips. On the other hand, fabricated selected ANP segment or BNP segment as an epitope is able to construct epitope-mediated MIPs (EMIPs) for ANP or BNP. The developed oxytocin or ANP sensor reached a detection limitation of 0.1nM with the dissociation constants being 30pM for oxytocin and 20pM for ANP. Moreover, BNP sensor achieved a detection limitation of 2.89pM with an even lower K d value as 2pM. Compared with the performance of EMIPs, the imprinted films showed high affinity and selectivity in special binding to CBCPHs. The developed MIPs-QCM biosensors thus provide an improved sensing platform using an amphiphilic monomer and may be useful for applications toward cyclotides, cystine knot motifs, or insulin-like peptides., (© 2019 European Peptide Society and John Wiley & Sons, Ltd.)