High Imprinting Factor Research Articles

Rational design based on multi-monomer simultaneous docking for epitope imprinting of SARS-CoV-2 spike protein

Among biomimetic strategies shaping engineering designs, molecularly imprinted polymer (MIP) technology stands out, involving chemically synthesised receptors emulating natural antigen-antibody interactions. These versatile ‘designer polymers’ with remarkable stability and low cost, are pivotal for in vitro diagnostics. Amid the recent global health crisis, we probed MIPs’ potential to capture SARS-CoV-2 virions. Large biotemplates complicate MIP design, influencing generated binding site specificity. To precisely structure recognition sites within polymers, we innovated an epitope imprinting method supplemented by in silico polymerization component screening. A viral surface Spike protein informed epitope selection was targeted for MIP development. A novel multi-monomer docking approach (MMSD) was employed to simulate classical receptor-ligand interactions, mimicking binding reinforcement across multiple amino acids. Around 40 monomer combinations were docked to the epitope sequence and top performers experimentally validated via rapid fluorescence binding assays. Notably, high imprinting factor polymers correlated with MMSD predictions, promising rational MIP design applicable to diverse viral pathologies.

Molecularly imprinted polymer for selective insulin capture and separation

Human insulin production was severely limited by its complex downstream processing. Herein, an insulin-imprinted polymer with shape-memorable imprint cavities was designed for the separation and purification of insulin from complex biofluids. N-isopropylacrylamide (NIPAM) was chosen as main monomer, and acrylamide (AAm) and (3-acrylamidopropyl)trimethylammonium chloride (AAPTAC) as functional monomers. A poly(l-lysine)-based peptide crosslinker, instead of the commonly used crosslinkers, was used to introduce poly(l-lysine) segments into the polymer. Because of the reversible and precise pH-induced helix-coil transition of the poly(l-lysine) segments, the imprint cavities in the polymer are shape-memorable. For this reason, the insulin template can be removed completely under mild conditions, meanwhile the imprinting efficiency is significantly improved. A high adsorption capacity (595 mg/g) and a high imprinting factor (5.83) were obtained, both of which are significantly higher than the previously developed insulin-imprinted polymers. The polymer also exhibits a high selectivity towards insulin and can be used repeatedly. Using this polymer insulin spiked in human serum was selectively captured and separated, demonstrating its ability for separation and purification of insulin from complex biofluids.

A smartphone sensing platform for the sensitive and selective detection of clothianidin based on MIP-functionalized lanthanide MOF.

Anovel molecularly imprinted nanomaterial (Eu (BTC)-MPS@MIP) was synthesized on the surface of silanized europium-based metal-organic frameworks (Eu (BTC)-MPS) using 1, 3, 5-benzotrioic acid (H3BTC) as a ligand. The resulting Eu (BTC)-MPS@MIP was applied to constructing a smartphone sensing platform for the sensitive and selective detection of clothianidin (CLT) in vegetables. The synthesized Eu (BTC)-MPS@MIP demonstrated the successful formation of a typical core-shell structure featuring a shell thickness of approximately 70 - 80nm. The developed sensing platform based on Eu (BTC)-MPS@MIP exhibited sensitivity in CLT detection with a detection limit of 4µg/L and a linear response in the range 0.01 - 10mg/L at excitation and emission wavelengths of 365nm and 617nm, respectively. The fluorescence sensing platform displayed excellent specificity for CLT detection, as evidenced by a high imprinting factor of 3.1. This specificity is primarily attributed to the recognition sites in the molecularly imprinted polymer (MIP) layer. When applied to spiked vegetable samples, the recovery of CLT ranged from 78.9 to 102.0%, with relative standard deviation (RSD) values falling between 2.2 and 6.2%. The quenching mechanism of Eu (BTC)-MPS@MIP toward CLT can be attributed to the inner filter effect (IFE), resulting from the optimal spectral overlap between the absorption spectrum of CLT and the excitation spectra of Eu (BTC)-MPS@MIP. The proposed method has the potential for extension to the detection of other pesticides by replacing the MIP recognition probes.

Computational simulation-assisted design and experimental verification of molecularly imprinted polymers for selective extraction of chlorogenic acid

Chlorogenic acid (CGA) is an active ingredient in honeysuckle with a broad-spectrum of antibacterial activity, suppressing tumor growth and other pharmacological effects. However, it is susceptible to damage during traditional extraction and separation processes. Therefore, developing selective and efficient extraction methods of CGA is essential. Based on computational molecular simulations, a reliable and efficient molecularly imprinted polymers (MIPs) were successfully developed for selective extraction of CGA. MIPs and non-molecularly imprinted polymers (NIPs) were synthesized using a precipitation polymerization method, employing three different functional monomers: [methacrylic acid (MAA), 4-vinylpyridine (4-VP), and methyl methacrylate (MMA)], with CGA serving as the template molecule. To simulate the polymers and predict the optimal ratio between the template and functional monomer, the computational studies and adsorption performance experiments were carried out. The adsorption characteristics and thermal stability of polymers were evaluated by isothermal adsorption, adsorption kinetics, selective adsorption and thermogravimetric analysis, aiming to obtain the MIPs with specific recognition and selectivity for CGA. When the molar ratio of template CGA to functional monomer 4-VP was 1:8, the prepared MIPs was found to have the maximum adsorption capacity (14.85 mg g−1) and the highest imprinting factor (1.74) at the CGA concentration of 100 mg L−1. These results were consistent with those obtained by computational molecular simulation. This study not only provides good guidance for developing separation materials for extracting CGA from natural plants but also inspires the application of computer simulation and molecular docking techniques in the preparation of specific MIPs materials.

Application of the GC-MS method in combination with preliminary solid phase extraction on a magnetic molecular imprinted polymer for the determination of bisphenol A in soils of various types

A method of gas chromatography-mass spectrometry (GC-MS) in combination with pre-concentration on a sorbent with BPA molecular imprints (dosage of sorbent — 50 mg, sorption time — 10 min, pH — 3, desorption with methanol) is used to determine bisphenol A (BPA). The sorbent extracts about 96% of BPA from aqueous solutions with a single sorption and is characterized by a high imprinting factor reaching 7.1. The samples of soils of urbanized territories, as well as typical chernozems and residual carbonate chernozems outside the large cities of the Voronezh region were studied. The limit of BPA detection was 0.07 μg/kg (in terms of dry soil), the range of the linearity of the calibration graph was 0.3 – 35 μg/kg. Determination of bisphenol is hindered by soil contamination with petroleum products, which can be eliminated by washing with heptane. It has been revealed that pH of soils has a significant effect on the BPA migration of along the soil profile. The concentration curves of the BPA distribution over the soil profile up to a depth of 1 m were plotted. The maximum BPA concentrations in the soils of urbanized territories depend on the contamination of the territory with polymer waste. The maximum BPA concentrations (29.84 μg/kg) were determined at a depth of 20 cm in samples taken near the landfill of municipal solid waste. At other points within the city limits, the maximum concentrations range within 5.38 – 8.77 μg/kg. Outside the city of Voronezh, the mobility of BPA increases in more alkaline typical and residual-calcareous chernozems and significant concentrations of the pollutant were found at a depth of 50 – 80 cm. The developed scheme can be applied to targeted screening and monitoring of the BPA content. The method can be used for BPA determination in soil horizons for various soil types, meteorological conditions (precipitation, annual temperature regime), and contamination of the territory (the presence of unauthorized landfills, MSW landfills, sewage treatment facilities near the sampling point).

A Novel Hexokinases Inhibitor Based on Molecularly Imprinted Polymer for Combined Starvation and Enhanced Photothermal Therapy of Malignant Tumors

The heat tolerance of tumor cells induced by heat shock proteins (HSPs) is the major factor that seriously hinders further application of PTT, as it can lead to tumor inflammation, invasion, and even recurrence. Therefore, new strategies to inhibit HSPs expression are essential to improve the antitumor efficacy of PTT. Here, we prepared a novel nanoparticle inhibitor by synthesizing molecularly imprinted polymers with a high imprinting factor (3.1) on the Prussian Blue surface (PB@MIP) for combined tumor starvation and photothermal therapy. Owing to using hexokinase (HK) epitopes as the template, the imprinted polymers could inhibit the catalytic activity of HK to interfere with glucose metabolism by specifically recognizing its active sites and then achieve starvation therapy by restricting ATP supply. Meanwhile, MIP-mediated starvation downregulated the ATP-dependent expression of HSPs and then sensitized tumors to hyperthermia, ultimately improving the therapeutic effect of PTT. As the inhibitory effect of PB@MIP on HK activity, more than 99% of the mice tumors were eliminated by starvation therapy and enhanced PTT.

One-pot synthesis of ion-imprinted three-dimensional porous material based on graphene oxide for the selective adsorption of copper(II)

Molecularly imprinted polymers (MIPs) are synthetic polymers with predetermined selectivity for a given analyte. One major problem associated with MIPs is the inaccessibility of a large fraction of the recognition sites that remain buried within the polymeric matrix. To address this problem, the high selectivity imparted by the imprinting technique and the porosity of three-dimensional (3D) graphene oxide (GO)-based porous materials were utilized in this work to prepare a 3D GO-based Cu(II)-ion-imprinted material (hereafter denoted as IIM) via one-pot reactions of GO, chitosan (CS), and glutaraldehyde in the presence of Cu(II). Results of equilibrium binding experiments show that IIM has a high template-ion binding capacity (1.75 mmol g−1) and good imprinting factor (2.19). Further, results of selectivity tests indicate that IIM has a high Cu(II)-recognition ability. IIM also has a fast binding rate and satisfactory reusability. In addition, the Langmuir isotherm model was well fitted with the experimental data, indicating the monolayer adsorption of Cu(II) ions. The present work provided a convenient approach to prepare 3D GO-based imprinted materials that are promising for enrichment or recycling of target compounds from wastewater.

A biobased magnetic dual-dummy-template molecularly imprinted polymer using a deep eutectic solvent as a coporogen for highly selective enrichment of organophosphates

An eco-friendly magnetic dual-dummy-template molecularly imprinted polymer (MDDMIP) was prepared by a “one-pot” green synthesis using mixed-valence iron hydroxide as the magnetic material, a deep eutectic solvent as the coporogen, and caffeic acid and glutamic acid as binary monomers. The adsorption properties toward organophosphorus pesticides (OPPs) were investigated. High adsorption capacities (269.65–304.93 mg g−1), quick adsorption times (20 s), and high imprinting factors (2.28–3.83) were obtained. The proposed MDDMIP was utilized for magnetic solid phase extraction (MSPE) of OPPs prior to quantification by high performance liquid chromatography (HPLC). The developed method exhibited outstanding linearity (0.05–500 μg L-1), low detection limits (0.003–0.015 μg L-1), and excellent enrichment factors (940–1310 folds). The MSPE-HPLC method was successfully applied for the detection of OPPs in vegetable, fruit, and grain samples with acceptable recoveries (80–119%). This method is a good potential method for the analysis of pesticide residues in complex matrices.

Simple and Fast Pesticide Nanosensors: Example of Surface Plasmon Resonance Coumaphos Nanosensor

Here, a molecular imprinting technique was employed to create an SPR-based nanosensor for the selective and sensitive detection of organophosphate-based coumaphos, a toxic insecticide/veterinary drug often used. To achieve this, UV polymerization was used to create polymeric nanofilms using N-methacryloyl-l-cysteine methyl ester, ethylene glycol dimethacrylate, and 2-hydroxyethyl methacrylate, which are functional monomers, cross-linkers, and hydrophilicity enabling agents, respectively. Several methods, including scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle (CA) analyses, were used to characterize the nanofilms. Using coumaphos-imprinted SPR (CIP-SPR) and non-imprinted SPR (NIP-SPR) nanosensor chips, the kinetic evaluations of coumaphos sensing were investigated. The created CIP-SPR nanosensor demonstrated high selectivity to the coumaphos molecule compared to similar competitor molecules, including diazinon, pirimiphos-methyl, pyridaphenthion, phosalone, N-2,4(dimethylphenyl) formamide, 2,4-dimethylaniline, dimethoate, and phosmet. Additionally, there is a magnificent linear relationship for the concentration range of 0.1–250 ppb, with a low limit of detection (LOD) and limit of quantification (LOQ) of 0.001 and 0.003 ppb, respectively, and a high imprinting factor (I.F.4.4) for coumaphos. The Langmuir adsorption model is the best appropriate thermodynamic approach for the nanosensor. Intraday trials were performed three times with five repetitions to statistically evaluate the CIP-SPR nanosensor’s reusability. Reusability investigations for the two weeks of interday analyses also indicated the three-dimensional stability of the CIP-SPR nanosensor. The remarkable reusability and reproducibility of the procedure are indicated by an RSD% result of less than 1.5. Therefore, it has been determined that the generated CIP-SPR nanosensors are highly selective, rapidly responsive, simple to use, reusable, and sensitive for coumaphos detection in an aqueous solution. An amino acid, which was used to detect coumaphos, included a CIP-SPR nanosensor manufactured without complicated coupling methods and labelling processes. Liquid chromatography with tandem mass spectrometry (LC/MS-MS) studies was performed for the validation studies of the SPR.

Kaempferol molecularly imprinted polymers: preparation, characterization and application to the separation of kaempferol from ginkgo leaves

AbstractIn this work, kaempferol molecularly imprinted polymers (MIPs) were screened in detail and were applied to the separation of kaempferol from real complex systems. Kaempferol‐MIPs with high affinity and selectivity for kaempferol could be prepared successfully by using kaempferol as the template molecule, 4‐vinylpyridine as the functional monomer, ethylene glycol dimethacrylate or divinylbenzene as the crosslinker, acetone or acetonitrile as the solvent. Scanning electron microscopy observation and Brunauer–Emmett–Teller measurement showed that the prepared MIPs had a heterogeneous pore structure and large specific surface area. Static and dynamic adsorption experiments and solid‐phase extraction application were performed to evaluate the performance of the prepared MIPs. Only the MIPs with both higher distribution coefficient and higher imprinting factor in the dynamic experiments had better ability to retain kaempferol. Using the screened MIPs as solid‐phase extraction sorbents, kaempferol and quercetin were extracted directly from the crude ginkgo leaves hydrolysate with high recovery and purity. Control experiments also showed that the screened MIPs were superior to commercially available adsorbents in terms of the separation of kaempferol from crude extracts. © 2023 Society of Industrial Chemistry.

Construction of anti-biofouling imprinted sorbents based on anisotropic polydopamine nanotubes for fast and selective capture of 2′-deoxyadenosine

Development of multifunctional sorbents with specific recognition, rapid separation and biofouling resistance is highly desired for the biological samples full of nutrients. Herein, anti-biofouling imprinted sorbents based on anisotropic polydopamine nanotubes (J-Ag@PDA NTs-MIPs) were synthesized for selective separation and enrichment of 2′-deoxyadenosine (dA). Molecularly imprinted polymers (MIPs) as recognition units were grafted onto the exposed outer surface of as-prepared polydopamine nanotubes (PDA NTs), and then Ag nanoparticles (around 40 nm) as antifouling units were independently loaded in their lumen by in situ growth. By batch mode experiments, J-Ag@PDA NTs-MIPs exhibited a fast adsorption equilibrium time (5.0 min) and an ultra-high adsorption capacity (223.3 μmol g−1) for dA. A high imprinting factor about 4.80 was observed for dA when comparing with the other structural analogues, resulting from the shape, group and size matching of imprinted sites to the template molecules. By evaluating the dA enrichment from spiked human serum solutions, the potential for capturing targeted dA in complex biological samples was confirmed. In addition, the loading of Ag NPs significantly enhanced the antibacterial performance of the imprinted sorbents, which was important for improving anti-biofouling property under complex eutrophic water environment. This work provided an approach for constructing plastic antibody with enhanced adsorption and anti-biofouling performance.

Sol-gel polymerization of silylated amino acids around a protein template yields selective biomimetic imprints

The development of artificial receptors able to selectively recognize a target protein is of particular interest in separation, diagnostics, and therapeutics fields. Herein, we disclose a method to prepare biomimetic and functionalized protein imprints in biocompatible conditions avoiding any protein denaturation. For that purpose, a set of different hybrid silylated amino acid derivatives were synthesized and used without tetraethyl orthosilicate to prepare our molecularly imprinted polymers, allowing to reduce to a minimum of the silicon amount, in order to obtain imprints made almost entirely of amino acids to mimic paratope surfaces of antibodies. Such functional building blocks were polymerized on the surface of magnetic silica nanoparticles at pH 8.5 in ultrapure water in the presence of two globular proteins: cytochrome C or lysozyme. The resulting imprinted hybrid materials were evaluated for their adsorption capacity, specificity, and selectivity by quartz-crystal microbalance with dissipation and magnetic enzyme-linked immunosorbent assay (ELISA) assays. High imprinting factors of 8.7 were measured for these biomimetic hybrid materials (corresponding to approximately 4000 and 450 ng of protein per cm2 immobilized on molecularly imprinted polymers and non-imprinted polymer nanoparticles, respectively), representing a significant breakthrough in sol-gel-based molecular imprinting materials. Moreover, competition experiments performed by magnetic ELISA (mELISA) show very good specificity of our imprints at the usual concentrations of ELISA measurements.

Aqueous phase synthesis of ion-imprinted cryogel for paper-based colorimetric detection of As(V) with high selectivity.

A novel hydrophilic As(V) ion-imprinted cryogel (IIC) was green prepared by cryogelation in aqueous environment which was coincident with the adsorption condition and can improve the specific recognition performance. The methacrylamido propyl trimethyl ammonium chloride (MPTAC) was selected as the functional monomer and the saturated adsorption capacity of the prepared IIC and NIC were 55.0mg/g and 29.4mg/g, and with high imprinting factor of 1.87. Additionally, the prepared IIC showed admirable reusability and highselectivity, and the recovery was in the range 81.2-97.9% with RSD range of 1.9-4.3%, which was similar to the value obtained by hydride generationatomic absorption spectrometry. IIC can be used as solid material for colorimetric detection at the ultraviolet wavelength of 858nm without color interference of material matrix, in the range 5-200μg/L (R2 = 0.990)with a detection limit of 0.970 µg/L. Obviously, this synthetic strategy provides a simple, efficient, and green method for the preparation of water-compatible ion-imprinted polymers providingselectiveseparation and detection of trace As(V) in real complex samples.

Advanced molecularly imprinted polymer-based paper analytical device for selective and sensitive detection of Bisphenol-A in water samples

Recently, the challenges in sensors have pointed towards rapid, on-site, and visual methods, especially when the sensing concerns toxic components such as Bisphenol-A (BPA). Herein, significant binding capacities for BPA have been featured the ultrasonically prepared molecularly imprinted polymer (MIP). Under the optimal adsorption conditions, which have been determined by a central composite design, the synthesized MIP exhibited a high imprinting factor of 9. The prepared MIP was effectively integrated into a membrane to fabricate an advanced paper-based analytical device (MIP-PAD) for the on-site colorimetric detection of BPA. The results of the evolved MIP-PAD were further analyzed by smartphone and processed by ImageJ software to quantify the BPA concentrations. The MIP-PAD platform exhibited a relevant performance for BPA sensitive sensing with a limit of detection and quantification of 0.03 μg/mL and 0.10 μg/mL, respectively. Moreover, trace levels of BPA (3.3 ng/mL) were successfully detected using MIP-PAD in SPE-tube with a loading volume of 1 mL. Besides, the fabricated chemical sensor revealed a high selectivity towards BPA after assessing various analogous compounds. Furthermore, this advanced technology was accurately and precisely applied for water samples and presented long-term stability.

Carbon dot-based molecularly imprinted fluorescent nanopomegranate for selective detection of quinoline in coking wastewater

Quinoline, as a refractory and toxic organic pollutant in coking wastewater, causes great harm to the environment and human health even in trace amount. To realize the selective and sensitive detection of quinoline in coking wastewater, a novel molecularly imprinted fluorescent nanopomegranate with carbon dots (CDs) as seeds and fluorescence source (CD-MIP) was prepared, using quinoline as the template, and N-(β-aminoethyl)-γ-aminopropyl trimethoxysilane (KH792) as the monomer. The preparation and detection conditions of CD-MIP were systematically optimized. The structure and detection performance of CD-MIP were investigated in detail. The resulting CD-MIP exhibits excellent photoluminescence performance, high detection sensitivity, good selectivity and reproducibility towards quinoline. Under the optimized conditions, the fluorescence intensity of CD-MIP shows a satisfying linearity with quinoline concentration in the range of 20–200 mg/L with a detection limit of 6.7 mg/L. Owing to the existence of imprinted cavities that highly match with quinoline, a high imprinting factor (3.46) for CD-MIP was obtained. In addition, CD-MIP represents a greater affinity towards quinoline than towards other analogues, as well as an outstanding anti-interference capability. For trace analysis in real coking wastewater, CD-MIP also gives satisfactory results. Therefore, CD-MIP shows promising application in the selective detection of trace quinoline in wastewater.

Synthesis of highly selective molecularly imprinted nanoparticles by a solid-phase imprinting strategy for fluorescence turn-on recognition of phospholipid

Molecularly imprinted polymers (MIPs) are artificial receptors with template tailored recognition sites complementary to the targets. The versatility of this molecular imprinting technique has been hampered by the lack of practical synthetic procedures to prepare highly selective MIP nanoparticles targeting phospholipids, which are challenging to be imprinted due to their amphiphilic structure. Here, a novel sedimentation-based solid-phase imprinting strategy is introduced relying on polymerization in the presence of template-modified silica nanospheres (SNs). To demonstrate this concept, the sphingosine-1-phosphate receptor agonist fingolimod phosphate (FP) was coupled to SNs which were dispersed in the prepolymerization medium consisting of the fluorescent functional monomer 1,8-bis(N-vinylimidazol-N′-methyl)anthracene bromide and the crosslinking monomer ethyleneglycol dimethacrylate. High dilution polymerization of the dispersion under agitation followed by simple sedimentation-based separation of the SN template resulted in the isolation of surface imprinted fluorescent MIP nanoparticles (FMIP NPs) in a high yield (17 %). The FMIP NPs displayed fluorescence enhancement in response to the template with a high imprinting factor (IF=9) under the experimental conditions and good specificity, and could recognize FP in human serum with recoveries of 68–74 %. Moreover, the template-modified SNs could be recycled for reuse. Such molecular imprinting strategy opens a new approach to produce highly selective artificial receptors targeting phospholipids.

Computational Modelling and Sustainable Synthesis of a Highly Selective Electrochemical MIP-Based Sensor for Citalopram Detection.

A novel molecularly imprinted polymer (MIP) has been developed based on a simple and sustainable strategy for the selective determination of citalopram (CTL) using screen-printed carbon electrodes (SPCEs). The MIP layer was prepared by electrochemical in situ polymerization of the 3-amino-4 hydroxybenzoic acid (AHBA) functional monomer and CTL as a template molecule. To simulate the polymerization mixture and predict the most suitable ratio between the template and functional monomer, computational studies, namely molecular dynamics (MD) simulations, were carried out. During the experimental preparation process, essential parameters controlling the performance of the MIP sensor, including CTL:AHBA concentration, number of polymerization cycles, and square wave voltammetry (SWV) frequency were investigated and optimized. The electrochemical characteristics of the prepared MIP sensor were evaluated by both cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. Based on the optimal conditions, a linear electrochemical response of the sensor was obtained by SWV measurements from 0.1 to 1.25 µmol L−1 with a limit of detection (LOD) of 0.162 µmol L−1 (S/N = 3). Moreover, the MIP sensor revealed excellent CTL selectivity against very close analogues, as well as high imprinting factor of 22. Its applicability in spiked river water samples demonstrated its potential for adequate monitoring of CTL. This sensor offers a facile strategy to achieve portability while expressing a willingness to care for the environment.

Anion Exchange Affinity-Based Controllable Surface Imprinting Synthesis of Ultrathin Imprinted Films for Protein Recognition.

Anion exchange affinity-based controllable surface imprinting is an effective approach to overcome low imprinting efficiency and high non-specific binding capacity. The template proteins were first immobilized on the anchored tetraalkylammonium groups of the nanoparticles via anion exchange affinity-based interactions, enabling monolayer sorption using a low template concentration. The combined use of surface-initiated photoiniferter-mediated polymerization to precisely control the imprinted film thickness, allowing the formation of homogeneous binding cavities, and the construction of effective binding sites resulted in a low non-specific binding capacity and high imprinting efficiency. The obtained imprinted films benefited from the anion exchange mechanism, exhibiting a higher imprinting factor and faster binding rate than the reference material. Binding tests revealed that the binding strength and selective recognition properties could be tuned to a certain extent by adjusting the NaCl concentration. Additionally, in contrast to the harsh template elution conditions of the covalent immobilization approach, over 80% of the template molecules were readily removed from the imprinted films using supersonic elution with an aqueous mixture of NaCl and HAc. Introducing template immobilization by anion exchange interactions to the synthesis of imprinted materials may provide a new approach for effective biomacromolecular imprinting.

Surface imprinted magnetic carbon nanofibrous microspheres with hierarchical porosity for the highly efficient and selective extraction of Brilliant Blue from food samples

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.

A highly sensitive surface acoustic wave sensor modified with molecularly imprinted hydrophilic PVDF for the selective amino acid detection

Molecularly imprinted templates for L-Tryptophan sensor using hydrophilic poly (vinylidene fluoride) (PVDF) was fabricated through in-situ polymerization of 2-hydroxyethyl methacrylate (HEMA) within PVDF matrix. The work proposes a novel strategy for the integration of antifouling layer modification for water treatment technique into molecular imprinting polymer for surface acoustic wave (SAW) sensor fabrication and demonstrates their effective utilization in direct biological applications. The L-Tryptophan templates were carefully prepared on the delay line area of a SAW device prepared through photolithographic method internally. The imprinted template was qualitatively analysed using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and atomic force microscopy (AFM) to understand the bond formation and distribution of imprinted textures on the receptor surface. Quantitative measurements as the L-Tryptophan receptor was conducted through SAW analysis within range of concentration 0.5–150 ng/ml and the sensor responded linearly with the varying concentration. The limit of detection and limit of quantification calculated to be 0.2 and 0.6 ng/ml, respectively. The mechanism of adsorption was further studied using Langmuir, Freundlich and Redlich-Peterson adsorption isotherm. The MIP modified SAW sensor had high selectivity in the presence of structural analogues such as D- tryptophan, ascorbic acid, leucine and tyrosine. The hydrophilic PVDF coated MIP-SAW sensor exhibited relatively high imprinting factor towards L-tryptophan of about 9.34.