Surface Molecular Imprinting Research Articles

Analysis of Trace Enrofloxacin in Environmental Waters by a Surface Molecular Imprinting Technique.

Surface-imprinted polymers (ZIF-67@MIPs) supported by ZIF-67 were prepared by precipitation polymerization using enrofloxacin (ENR) as the template molecule, methacrylic acid as the functional monomer, and ethylene glycol dimethacrylate as the cross-linker. ZIF-67@MIPs were characterized by Fourier transform infrared spectrometry, X-ray diffraction, scanning electron microscopy, and particle size distribution. The adsorption performance of the polymer was studied. The adsorption equilibrium was reached within 30 min. The maximum adsorption was 9.02 μg·mg-1. The imprinting factor was 2.58. The polymer was then used as a sorbent of a solid-phase extraction column for the separation and purification of ENR in real water samples. The extraction conditions were optimized. The method was established by high-performance liquid chromatography, and the linearity was verified by UPLC-MSMS. The correlation coefficient and limits of detection and quantification were 0.9999, 0.23 ng·mL-1, and 0.76 ng·mL-1, respectively. The recoveries were in the range of 83.79-100.68%; the relative standard deviation was 4.46-7.35%. The above data indicated that the method could be used for the separation and enrichment of ENR in real samples.

A novel molecularly imprinted solid phase based on SiO2-Ag2O double-nucleation doped with graphene oxide for extraction and determination of flavonoids from Acanthaceae ebracteatus via HPLC-MS/MS

(Objectives) A novel method was developed for extracting and determining flavonoids from marine mangrove medicinal plants. This approach utilizes surface molecular imprinting to increase selectivity. Graphene oxide doped with a SiO2–Ag2O dual core structure served as a scaffold for synthesizing multilayer surface-imprinted polymers. The surface of the SiO2-Ag2O@GO composite was modified through self-polymerization. (Methods) Acacetin molecularly imprinted polymers (AMIPs) were created via surface-initiated precipitation polymerization with acacetin as the template. These AMIPs were synthesized and characterized via ultraviolet (UV) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Recycling experiments demonstrated the stability of the AMIPs. Analysis of the adsorption mechanism via the Langmuir and Freundlich models indicated that the Langmuir model was more suitable for predicting AMIPs. (Results) Scatchard plots showing two different binding sites of AMIPs for acacetin adsorption at various concentrations. The class selectivity of AMIPs for flavonoids was found in Acanthaceae ebracteatus. Compared with other analogs, competitive binding experiments revealed that the polymer had greater selectivity for acacetin. After AMIP solid-phase extraction (AMISPE), the linearity, LOD, LOQ, intraday and interday variabilities, recovery, and repeatability of AMIPs combined with HPLC–MS/MS were validated, confirming the method’s selectivity, precision, accuracy, and reproducibility. The contents of acacetin, apigenin, kaempferol, luteolin, quercetin, and genistein in Acanthaceae ebracteatus were determined. (Conclusions) These results indicate that AMISPE coupled with HPLC–MS/MS is a new, simple, and practical method for extracting, purifying, and enriching flavonoids from complex samples, such as those of herbs and other natural marine plants.

Computational simulation-assisted template selection of magnetic MOFs molecularly imprinted materials applying the adsorption and detection of multiple fluoroquinolones

This study utilized computational simulation and surface molecular imprinting technology to develop a magnetic metal-organic framework molecularly imprinted polymer (Fe3O4@ZIF-8@SMIP) capable of selectively recognizing and detecting multiple fluoroquinolones (FQs). The Fe3O4@ZIF-8@SMIP material was synthesized using the “common” template-ofloxacin, identified by computational simulation, demonstrating notable adsorption capacity (88.61–212.93 mg g−1) and rapid mass-transfer features (equilibration time: 2–3 min) for all tested FQs, consistent with Langmuir adsorption model. Subsequently, this material was employed as a magnetic solid-phase-extraction adsorbent for adsorption and detection of multiple FQs by combining with high performance liquid chromatography. The developed method exhibited good linearity for various FQs within the concentration range of 0.1–500 μg L−1, with low limit of detection (0.0605–0.1529 μg L−1) and limit of quantitation (0.2017–0.5097 μg L−1). Satisfactory recoveries (88.38–103.44%) were obtained when applied to spiked food samples, demonstrating the substantial potential of this Fe3O4@ZIF-8@SMIP material for rapid enrichment and identification for multiple FQs residues.

Reusable magnetic molecular imprinted polymers based on magnetic graphene oxide for selective identification and detection of eugenol in environmental water samples.

In this study, a reliable method for determining eugenol content in environmental water samples was established by combining magnetic solid-phase extraction with high-performance liquid chromatography. Magnetic molecular imprinted polymers MGO@MIPs were prepared through surface molecular imprinting technique with eugenol as the template molecule. The material displayed good superparamagnetic properties and magnetic responsiveness in favor of rapid separation. The adsorption properties of MGO@MIPs for eugenol were evaluated through adsorption kinetics and selectivity experiments. MGO@MIPs were found to have favorable reusability and obvious selectivity for eugenol. In addition, adsorption and elution conditions were investigated. Under optimal conditions, a linear relationship was obtained between the concentration of eugenol and its peak area in the range of 0.02-5mg/L (R2 = 0.9998) and the limit of detection was 4.0 × 10-6mg/mL. The performance of the established method was assessed with the average recovery of 96.59-102.20% and the relative standard deviation (RSD) below 3.5%. The application of this method provides a new perspective for the separation, enrichment and detection of eugenol in water environment.

Molecularly imprinted beads based on modified cellulose hydrogel:A novel solid phase extraction filler for specific adsorption of camptothecin

Traditional solid phase extraction (SPE) suffers from a lack of specific adsorption. To overcome this problem, a combination of adsorption method and molecular imprinting technology by polydopamine modification was proposed to realize specific recognition of target compounds in SPE, which is of great significance to improve the separation efficiency of SPE. Cellulose hydrogel beads were prepared by dual cross-linking curing method and modified with polydopamine to make them hydrophilic and biocompatible. Subsequently, cellulose hydrogel-based molecularly imprinted beads (MIBs) were synthesized by surface molecular imprinting technology and used as novel column fillers in SPE to achieve efficient adsorption (34.16 mg·g−1) with specific selectivity towards camptothecin (CPT) in 120 min. The simulation and NMR analysis revealed that recognition mechanism of MIBs involved hydrogen bond interactions and Van der Waals effect. The MIBs were successful used in separating CPT from Camptotheca acuminata fruits, exhibiting impressive adsorption capacity (1.19 mg·g−1) and efficient recovery of CPT (81.54 %). Thus, an environmentally friendly column filler for SPE was developed, offering a promising avenue for utilizing cellulose-based materials in the selective separation of natural products.

Development of a simple polymer-based sensor for detection of the Pirimicarb pesticide

In this study, a sensitive and selective fluorescent chemosensor was developed for the determination of pirimicarb pesticide by adopting the surface molecular imprinting approach. The magnetic molecularly imprinted polymer (MIP) nanocomposite was prepared using pirimicarb as the template molecule, CuFe2O4 nanoparticles, and graphene quantum dots as a fluorophore (MIP-CuFe2O4/GQDs). It was then characterized using X-ray diffraction (XRD) technique, Fourier transforms infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), and transmission electron microscopy (TEM). The response surface methodology (RSM) was also employed to optimize and estimate the effective parameters of pirimicarb adsorption by this polymer. According to the experimental results, the average particle size and imprinting factor (IF) of this polymer are 53.61 nm and 2.48, respectively. Moreover, this polymer has an excellent ability to adsorb pirimicarb with a removal percentage of 99.92 at pH = 7.54, initial pirimicarb concentration = 10.17 mg/L, polymer dosage = 840 mg/L, and contact time = 6.15 min. The detection of pirimicarb was performed by fluorescence spectroscopy at a concentration range of 0–50 mg/L, and a sensitivity of 15.808 a.u/mg and a limit of detection of 1.79 mg/L were obtained. Real samples with RSD less than 2 were measured using this chemosensor. Besides, the proposed chemosensor demonstrated remarkable selectivity by checking some other insecticides with similar and different molecular structures to pirimicarb, such as diazinon, deltamethrin, and chlorpyrifos.

An anti-fouling surface molecularly imprinted ratiometric electrochemical biosensor for SARS-CoV-2 spike protein

An anti-fouling surface molecularly imprinted (SMI) ratiometric electrochemical biosensor was fabricated for the detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) spike protein (S protein). Polypyrrole (PPy) was electrodeposited on the electrode surface by using ferrous phthalocyanine (PcFe) and sodium alginate (SA) as the dopants, which acted as the molecularly imprinted polymers (MIPs). The SMI electrochemical biosensor could be used for the detection of SARS-CoV-2 S protein based on the ratiometric signals of the internal reference (PcFe) and the external probe ([Fe(CN)6]3−/4−). Under optimized conditions, the as-fabricated SMI ratiometric biosensor showed a wide linear range of 100 fg mL−1 ∼ 100 ng mL−1 with a low limit of detection (LOD) of 30.1 fg mL−1. Nonspecific adsorption of interfering substances onto the SMI biosensor surface could be significantly reduced due to the outstanding anti-fouling ability of SA, as revealed by fluorescence microscopy. Finally, the reliability of the SMI ratiometric electrochemical biosensor was demonstrated by the detection of SARS-CoV-2 S protein in clinical serum samples. The findings of this work open a new avenue in clinical diagnosis of COVID-19.

Optimization and performance evaluation of a fluorescent sensor for residual sulfonamide antibiotics in honey samples

AbstractIn the quest to address the mounting concerns over sulfonamide antibiotic residues in food, which pose significant threats to public health and food safety, this study introduces a cutting‐edge detection method. Surface molecular imprinting on silicon nanoparticles is harnessed to fabricate a novel fluorescent sensor that exploits the luminescent properties of cadmium telluride (CdTe) quantum dots. This innovative approach aims to detect residual sulfonamide antibiotics with high specificity and sensitivity. At the heart of this research is the development of a core‐shell nanostructure, where silicon dioxide serves as the core, and a molecularly imprinted polymers (MIPs) layer, tailored to recognize sulfamethazine (SM2), forms the shell. The pivotal advancement in this sensor design is the integration of highly fluorescent CdTe quantum dots within the MIPs layer, which significantly enhances the signal response, enabling the detection of SM2 with remarkable precision. The synthesis of this sensor employs a novel strategy, utilizing 3‐aminopropyltriethoxysilane as the functional monomer, while tetraethyl orthosilicate and ammonium hydroxide act as catalysts to facilitate the polymerization reaction. This meticulous process yields a stable core‐shell structure with active fluorescent properties. Experimental results reveal that under optimal conditions, the sensor exhibits a robust linear response to SM2 concentrations ranging from 10 to 60 μmol L−1, with a detection limit as low as 0.78 μmol L−1. Furthermore, when applied to real food samples, such as honey, the sensor not only demonstrates high recovery rates of 92.3%–98.1%, but also maintains a low relative standard deviation of less than 2.5%. The implications of this study are far‐reaching, offering a promising avenue for the rapid and reliable monitoring of antibiotic residues in the food supply chain, thereby safeguarding consumer health and upholding food safety standards.

Preparation of surface molecular imprinting fluorescent sensor based on magnetic porous silica for sensitive and selective determination of catechol.

A magnetic fluorescent molecularly imprinted sensor was successfully prepared and implemented to determine catechol (CT). Fe3O4 nanoparticles were synthesized by the solvothermal technique and mesoporous Fe3O4@SiO2@mSiO2 imprinted carriers were prepared by coating nonporous and mesoporous SiO2 shells on the surface of the Fe3O4 subsequently. The magnetic surface molecularly imprinted fluorescent sensor was created after the magnetic mesoporous carriers were modified with γ-methacryloxyl propyl trimethoxy silane to introduce double bonds on thesurface of the carries and the polymerization was carried out in the presence of CT and fluorescent monomers. The magnetic mesoporous carriers were modified with γ-methacryloxyl propyl trimethoxy silane and double bonds were introduced on the surface of the carriers. After CT binding with the molecularly imprinted polymers (MIPs), the fluorescent intensity of the molecularly imprinted polymers (Ex = 400nm, Em = 523nm) increased significantly. The fluorescent intensity ratio (F/F0) of the sensor demonstrated a favorable linear correlation with the concentration of CT between 5 and 50μM with a detection limit of 0.025μM. Furthermore, the sensor was successfully applied to determine CT in actual samples with recoveries of 96.4-105% and relative standard deviations were lower than 3.5%. The results indicated that the research of our present work provided an efficient approach for swiftly and accurately determining organic pollutant in water.

Deep Eutectic Solvent Modified Surface Molecular Imprinting Polymers on Boron Nitride Sheets for Specific Recognition of the Genotoxic Impurity Benzo(a)Pyrene

As a typical genotoxic impurity (GTI), the concentration of benzo(a)pyrene (BaP) must be below the threshold of toxicological concern (TTC). However, achieving a trace BaP is a significant challenge by conventional separation media. Utilizing the unique recognition capabilities of surface molecular imprinting polymers (SMIPs), the versatility of N-vinyl-2-pyrrolidone deep eutectic solvents (NVP-DES), and the high surface area of two-dimensional nano-boron nitride (2D-nano-BN) sheets, a series of functionalized 2D-BN materials were prepared (NVP-DES-SMIP@2D-nano-BN) for the specific recognition and removal of BaP. Utilizing 2D-nano-BN sheets as the base, four NVP-DESs were employed as monomers, BaP as the template, EGDMA as the cross-linker, and BPO/DMA as the initiator to prepare NVP-DES-SMIP@2D-nano-BN. The free energy of DES was computed using Gaussian software, and characterization of NVP-DES-SMIP@2D-nano-BN was performed using Fourier transform infrared spectroscopy and transmission electron microscopy. Quantitative and qualitative determinations of BaP were conducted using high performance liquid chromatography and fluorescence. Using a recognition model, NVP-DES-SMIP@2D-nano-BN exhibited a Freundlich isotherm fit and second-order kinetics for BaP.

Fluorescent Probes Based on Ag NPs@N/GQDs and Molecularly Imprinted Polymer for Sensitive Detection of Noradrenaline in Bananas.

Fluorescence intensity and selective recognition ability are crucial factors in determining the analytical techniques for fluorescent probes. In this study, a core-shell fluorescent material, composed of silver nanoparticles@nitrogen-doped graphene quantum dots (Ag NPs@N/GQDs), was synthesised using mango leaves as the raw material through a thermal cracking method, resulting in strong fluorescence luminescence intensity. By employing noradrenaline as a template molecule and using a surface molecular imprinting technique, a molecularly imprinted membrane (MIP) was formed on the surface of the fluorescent material, that was subsequently eluted to obtain a highly specific, fluorescent probe capable of recognising noradrenaline. The probe captured various concentrations of noradrenaline using the MIP, which decreased the fluorescence intensity. Then a method for detecting trace amounts of noradrenaline was established. This method exhibited a linear range from 0.5 -700pM with a detection limit of 0.154pM. The proposed method was implemented in banana samples. Satisfactory recoveries were confirmed at four different concentrations. The method presented a relative standard deviation (RSD) of less than 5.0%.

Using Quercetin to Construct Molecularly Imprinting Polymer in the Preparation and Enrichment of Flavonol and Flavonoid Compounds.

Flavonol and flavonoid compounds are important natural compounds with various biomedical activities. Therefore, it is of great significance to develop a strategy for the specific extraction of flavonol and flavonoid compounds. Quercetin is a well-studied flavonoid possessing many health benefits. This compound is a versatile antioxidant known to possess protective abilities against body tissue injury induced by pathological situations and various drug toxicities. Although quercetin is widely distributed in many plants, its content generally is not very high. Therefore, the specific extraction of quercetin as well as other flavonol and flavonoid compounds has profound significance. In this work, the quercetin molecularly imprinting polymer (QMIP) was successfully prepared, in which a typical flavonol quercetin was selected as the template molecule. QMIP was synthesized by performing the surface molecular imprinting technology on the surface of NH2-MIL-101(Fe). Our study results showed that QMIP exhibited quick binding kinetic behavior, a high adsorption capacity (57.04[Formula: see text]mg/g), and the specific recognition ability toward quercetin compared with structurally distinct compounds (selective [Formula: see text]). The specific adsorption ability of quercetin by QMIP was further explained using computation simulation that molecules with non-planar 3D conformations hardly entered the molecularly imprinted cavities on QMIP. Finally, QMIP was successfully used for the specific extraction of quercetin and five other flavonol and flavonoid compounds in the crude extracts from Sapium sebiferum. This study proposes a new strategy to synthesize the molecularly imprinted polymer based on a single template for enriching and loading a certain class of active ingredients with similar core structures from variable botanicals.

Selective extraction and quantitative analysis of pyrroloquinoline quinone from food.

Pyrroloquinoline quinone (PQQ) is a bioactive compound that has attracted significant attention due to its potential health benefits. In this study, we developed a new magnetic molecularly imprinted nanoparticle (MMIN) for the selective extraction and determination of PQQ from food samples. The MMIN was synthesized using a surface molecular imprinting technique with PQQ as the template molecule, Fe3O4 nanoparticles as the magnetic core, and methacrylic acid as the functional monomer. The MMIN exhibited high selectivity and affinity towards PQQ, allowing for efficient extraction and preconcentration of PQQ from complex food matrices. The extracted PQQ was then quantified using HPLC-DAD. The developed method showed good linearity (R2 = 0.9985) and low limits of detection (0.03 μg L-1). The accuracy and precision of the method were evaluated by analyzing spiked food samples, with average recoveries close to 89.8%. The MMIN also demonstrated good reusability, with negligible decrease in extraction efficiency after five cycles of use. Overall, the developed MMIN-based method provides a reliable and efficient approach for the analysis of PQQ in food samples.

Development of magnetic molecularly imprinted polymers for selective extraction of Benzoxazolinone-type alkaloids from acanthus plants

Benzoxazolinone-type alkaloids found in Acanthus ebracteatus and Acanthus ilicifolius Linnaeus possess various beneficial properties, such as antileishmanial, antipyretic, analgesic, antibacterial, and antioxidant effects. In this study, we employed a surface imprinting technique on nanomaterials. We utilized functionalized Fe3O4@SiO2NH2 as a scaffold, with 2-benzoxazolinone and 2H-1,4-benzoxazin-3(4H)-one serving as dual templates, methacrylic acid (MAA) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as a crosslinker, and 2,2-azodiisobutyric nitrile (AIBN) as the initiator. Prior to polymerization, we screened functional monomers using ultraviolet (UV) spectroscopy. The resulting magnetic surface molecular imprinting polymer (Fe3O4@SiO2@MIP) was thoroughly characterized using Fourier transform infrared spectrometry (FT-IR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). We also conducted assessments of its adsorption isotherms, dynamics, and selective binding capabilities. Our findings indicate that the MIPs exhibited exceptional selective recognition performance. Through meticulous screening and optimization of extraction and separation conditions, we established an LC‒MS/MS method based on magnetic solid-phase extraction technology. The method exhibited a recovery range of 78.80–106.99 % (RSD, 0.46–3.31 %) for 2-benzoxazolinone, with a limit of detection (LOD) and limit of quantification (LOQ) of 2.85 and 9.00 μg L−1, respectively. For 2H-1,4-benzoxazin-3(4H)-one, the method yielded a recovery range of 84.75–103.53 % (RSD, 0.07–5.96 %), with an LOD and LOQ of 3.60 and 12.60 μg L−1, respectively, in real samples. The resulting Fe3O4@SiO2@MIP demonstrated a high capacity for class-specific adsorption.

Boronate affinity-based surface molecularly imprinted polymer microspheres using polyethyleneimine/dopamine coating for efficient selective recognition and separation of Ginsenoside Rb1

A novel approach combining boronate affinity with surface molecular imprinting was developed for the specific recognition and separation of ginsenoside Rb1. Firstly, the boronic acid-functionalized polymer microspheres were prepared as inner cores via suspension polymerization using methyl methacrylate, ethyleneglycol dimethacrylate, and 4-vinylphenyl boronic pinacol ester (4-VBPE) as polymerization monomers. Then, the Ginsenoside Rb1 (GRb1) template was covalently pre-anchored onto the surface of microspheres through boronate affinity binding after the hydrolysis of 4-VBPE. Finally, dopamine and polyethyleneimine were used as co-coating monomers to form a thickness-controllable imprinting layer onto the polymer microspheres via in-water self-copolymerization. The key factors affecting specific recognition, including the boronic acid content, adsorption media, and polymerization time were carefully optimized. The resulting molecularly imprinted microspheres (MIMs) exhibited strong surface hydrophilicity. In the aqueous media, the optimal adsorption capacity for the template reached 81.45 μmol g−1, and the imprinting factor was 5.32. The specific evaluation showed that the MIMs had a much higher selectivity for GRb1 than its analogues, and the selectivity coefficients were all higher than 2.4. In addition, the MIMs can be applied as adsorbents for solid-phase extraction to selectively separate ginsenosides from American ginseng extract. The eluting recovery ratios of GRb1, GRg2, and GRd reach 92.39%, 88.90%, and 92.49%, respectively.

A surface molecularly imprinted microfluidic paper based device with smartphone assisted colorimetric detection for butachlor in mung bean

A microfluidic paper chip colorimetric detection system based on surface molecular imprinting of zinc ferrite nanoparticles was established, and the detection images were obtained by smartphone for gray value analysis and determination of butachlor. The best functional monomers and addition ratio were selected by quantum chemical simulation calculation, the properties of the prepared molecularly imprinted polymers were analyzed, and the detection conditions were optimized. The linear range, sensitivity, and selectivity of the method were evaluated. The results showed that under the optimum conditions, the concentration of 2–80 ng/g had a good linear relationship (R2 is 0.9953), the detection limit was 1.43 ng/g, the specificity was good, and the whole detection process did not exceed 20 min. The microfluidic paper chip was applied to detect butachlor in mung bean samples. The results showed that the recovery was 93.4–106.4 %, and the relative standard deviation was less than 5.6 %.

Construction of Highly Active and Selective Molecular Imprinting Catalyst for Hydrogenation.

Surface molecular imprinting (MI) is one of the most efficient techniques to improve selectivity in a catalytic reaction. Heretofore, a prerequisite to fabricating selective catalysts by MI strategies is to sacrifice the number of surface-active sites, leading to a remarkable decrease of activity. Thus, it is highly desirable to design molecular imprinting catalysts (MICs) in which both the catalytic activity and selectivity are significantly enhanced. Herein, a series of MICs are prepared by sequentially adsorbing imprinting molecules (nitro compounds, N) and imprinting ligand (1,10-phenanthroline, L) over the copper surface of Cu/Al2O3. The resulting Cu/Al2O3-N-L MICs not only offer promoted catalytic selectivity but also enhance catalytic activity for nitro compounds hydrogenation by an creating imprinting cavity derived from the presorption of N and forming new active Cu-N sites at the interface of the copper sites and L. Characterizations by means of various experimental investigations and DFT calculations disclose that the molecular imprinting effect (promoted activity and selectivity) originates from the formation of new active Cu-N sites and precise imprinting cavities, endowing promoted catalytic selectivity and activity on the hydrogenation of nitro compounds.

A nanocellulose molecularly imprinted membrane: Preparation, characterization and application in targeted separation of taxane 10-deacetylbaccatin III

Targeted separation of active phytochemicals is urgently needed in the natural medicine field. In this paper, due to the natural porosity and high biocompatibility of cellulose, a nanocellulose membrane combined with surface molecular imprinting was successfully prepared; the efficient nanocellulose-based molecular imprinted membrane (NC-MIM) provided good adsorption for the targeted separation of phytochemicals such as 10-deacetylbaccatin III (10-DAB), an essential intermediate in the synthesis of the anticancer drug paclitaxel. Through a series of characterization and adsorption experiments, the adsorption mechanism of NC-MIM was determined. At pH 8.0 and temperatures of 20 °C–40 °C, the maximum capacity of NC-MIM for adsorption of 10-DAB reached 66.90 mg g − 1, and the content of 10-DAB was dramatically increased 17.5-fold after adsorption. The specific adsorption results showed that NC-MIM had excellent capacity for targeted separation of 10-DAB from among taxane structural analogues. Even after ten cycles, NC-MIM demonstrated a remarkable adsorption capacity of 86.43%, thereby indicating exceptional selectivity and stability. The successful implementation of NC-MIM for green, safe, and efficient enrichment of phytochemicals from plants provides a promising new approach and valuable insights into its practical application.

Recent advances in the applications of metal-organic frameworks-based molecularly imprinted materials

Molecularly imprinted polymers have received wide attention from various fields owing to their pre-designable, recognition ability, and practicality. However, the disadvantages of the traditional embedding method, which include a slow recognition rate, uneven site recognition, low binding capacity, and incomplete template molecule elution, limit the development of molecular imprinting technology. Surface molecular imprinting techniques have been developed to effectively solve these problems, and different materials are used as carriers in the synthesis of molecularly imprinted polymers. Metal-organic frameworks (MOFs) show great potential as carriers. Because of their high porosity and specific surface area, MOFs can provide a large number of active sites for molecular imprinting, which can improve their detection sensitivity. The variable metal centers and organic ligands of MOF materials can also lead to multiple structures and functions. Numerous types of MOF materials have been synthesized, and the properties of these materials can be tailored by adjusting their pore size and introducing functional groups. MOFs and molecular imprinting technology can be combined to take full advantage of the specific adsorption of molecular imprinting technology and the large specific surface area and multiple active sites of MOFs, thereby expanding the application range of the resulting materials. In this paper, five aspects of the concept of MOF functionalization are discussed: introduction of special ligands, regulation of metal central sites, formation of MOF complexes, derivatization of MOFs, and sacrificial MOFs. The applications of MOF-based molecularly imprinted materials in catalysis, sample pretreatment, drug carriers, fluorescence sensors, and electrochemical sensors are also reviewed. Finally, the existing problems and future development of MOF-based molecularly imprinted materials are discussed and prospected.

Novel molecularly imprinted aerogels: Preparation, characterization, and application in selective separation for oleanolic acid in lingonberry

An oleanolic acid (OA) surface molecularly imprinted polymer silylated porous composite aerogels (OA-MIP@Si-PC-aerogels) adsorbent material was successfully prepared and characterized. The material not only has a great selectivity for the target molecule OA but also has other noteworthy qualities including high stability, excellent repeatability, and a sizable adsorption capacity. via cellulose and sodium alginate as the main materials, the carrier Si-PC-aerogels were made through ionic cross-linking, chemical cross-linking, and silylation procedures. By adopting a surface molecular imprinting approach on Si-PC-aerogels, OA-MIP@Si-PC-aerogels were effectively created utilizing OA as the template molecule and MAA as the functional monomer. Due to the presence of a specific imprinted layer on the aerogel surface, the adsorption capacity of OA-MIP@Si-PC-aerogels for OA could reach 66.20 mg g−1. OA-MIP@Si-PC-aerogels could achieve a 68.86% yield of OA from the extracts of lingonberry (Vaccinium Vitis-Idaea L.). The adsorption capacity remained at 90% after five consecutive adsorption-desorption cycles. HepG2 cells were exposed to OA that was effectively enriched with OA-MIP@Si-PC-aerogels in lingonberry (Vaccinium Vitis-Idaea L.) fruit homogenates. This OA significantly inhibited the growth of HepG2 cells in vitro. It further demonstrated that OA-MIP@Si-PC-aerogels could efficiently target OA enrichment and separation with good recovery.