Molecular Imprinting Technology Research Articles

Porous molecularly imprinted beads for highly specific separation of 10-hydroxycamptothecine: An imprinted strategy based on modified cellulose hydrogel

10-hydroxycamptothecine (HCPT), known as a natural alkaloid with significant anti-cancer properties in Camptotheca acuminata, has valuable application prospects in health and medicine and has attracted worldwide attention especially in the field of cancer research. In this study, a porous cellulose hydrogel-based molecularly imprinted bead (PCH@MIBs) with high affinity and selectivity was prepared and served as novel fillers of solid phase extraction (SPE) for selectively separating HCPT. The combination of polydopamine (PDA) modified cellulose hydrogel and highly selective molecular imprinting technology enabled the efficient and targeted adsorption for template molecules. The mixture of nano-calcium carbonate and cellulose solution underwent a reaction with an acidic coagulation bath, which endowed the cellulose hydrogel beads with porous structures. Porous cellulose hydrogel beads were coated with a PDA layer, followed by the preparation of PCH@MIBs using HCPT as template molecules and acrylamide (AM) as functional monomers, resulting in hydrogel-based materials with specific adsorption cavities matched to HCPT. The PCH@MIBs exhibited excellent adsorption capacity (57.87 mg·g−1) and adsorption selectivity (IF = 3.75), as well as good reusability (5 of cycles). The PCH@MIBs were successfully used to separate HCPT from C. acuminata fruits, with an impressive adsorption capacity (0.0974 mg·g−1) and recovery of HCPT (91.27 %). Mechanism analysis demonstrated that the recognition of PCH@MIBs was primarily achieved through non-covalent interactions between AM and HCPT, specifically hydrogen bonds and Van der Waals forces. This work proposes a novel strategy for constructing porous cellulose-based molecularly imprinted hydrogel beads to specific capture targeted compound, which have broad potential for practical application.

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.

Surface molecularly imprinted polymer/covalent organic framework/silica composite material with specific recognition ability and excellent chromatographic performance

Facing with the difficulty of specific chromatographic separation of nucleoside drugs, this study prepared a surface molecularly imprinted polymer (SMIP) modified covalent organic framework (COF) coated silica stationary phase based on the specificity of molecular imprinting technology and the powerful chromatographic separation performance of COF. This novel SMIP-COF@SiO2 stationary phase can not only specifically identify template molecule and structural analogs, but can also be used to separate multiple types of analytes, such as B vitamins, sulfonamides, alkylbenzenes, phenyl ketones, polycyclic aromatic hydrocarbons and environmental endocrine disruptors, which satisfies the need for complex sample separation. Various retention mechanisms have been investigated and multiple interactions between the SMIP- COF@SiO2 stationary phase and the analytes are discovered. The chromatographic performance of SMIP-COF@SiO2 is far superior to that of the SMIP@SiO2 and COF@SiO2. Furthermore, the SMIP-COF@SiO2 stationary phase can be successfully used to analyze polycyclic aromatic hydrocarbons in the environmental water sample and detect whitening ingredient in skincare product, indicating its great potential for application in various fields.

In-situ targeted removal of naphthalene from groundwater by peroxymonosulfate activation using molecularly imprinted activated carbon: Efficacy, mechanism and applicability

Efficient removal of low-concentration refractory polycyclic aromatic hydrocarbons (PAHs) pollutants is crucial for ensuring groundwater safety. In this study, surface molecularly imprinted catalyst (MIP@AC) was developed based on activated carbon (AC) and molecular imprinting technology, and then MIP@AC was introduced into the simulated permeable reaction barrier to evaluate the performance of MIP@AC activated peroxymonosulfate (PMS) in in-situ targeted remediation of naphthalene (NAP) contaminated groundwater. The results showed that the relative adsorption selectivity coefficient and relative degradation selectivity coefficient of the MIP@AC material relative to the non-imprinted material AC was as high as 31.47 and 10.88, respectively; that is, MIP@AC can better resist the interference of competitive pollutants and achieve efficient targeted removal of NAP. Additionally, the reactive oxygen species (ROS) yield was higher in the MIP@AC/PMS system compared to the AC/PMS system. The target pollutant NAP was precisely enriched in the imprinted cavity of the MIP@AC, realizing that ROS production and pollutant degradation occurred simultaneously in the MIP@AC imprinted cavity. Therefore, the spatial confinement effect of the imprinted cavity shortened the mass transfer distance between the ROS and NAP, thereby reducing the loss of ROS due to self-quenching. Besides, Cl- significantly promoted the targeted removal of NAP, while HCO3- had a slight inhibitory effect; humic acid had no effect because of its larger molecular structure, which does not fit into the small imprinted cavities preferred by NAP. Importantly, the MIP@AC/PMS system demonstrated effective anti-complex matrix interference ability and targeted removal performance for NAP under natural groundwater conditions. This study can promote further research on the surface molecularly imprinted catalyst/PMS system as a new strategy for in-situ targeted remediation technology of contaminated groundwater.

A molecule-imprinted electrochemiluminescence sensor based on CdS@MWCNTs for ultrasensitive detection of fenpropathrin.

A molecularly-imprinted electrochemiluminescence sensor was constructed for the determination of fenpropathrin (FPT) by molecular imprinting technology. In this sensing platform, the introduction of CdS@MWCNTs significantly enhanced the initial ECL signal of the luminol-O2 system. Specifically, MWCNTs was used as a carrier to adsorb more CdS, in which CdS acted as a co-reaction promoter for luminescence. Molecularly imprinted polymer (MIP) containing specific recognition sites of FPT was used as the material for selective recognition. With increasing amount of FPT the ECL signal decreased. Under the optimum conditions, the ECL response was linearly related to the logarithm of FPT concentration. The developed ECL sensor allowed for sensitive determination of FPT and exhibited a wide linear range from 1.0 × 10- 10 mol L- 1 to 1.0 × 10- 6 mol L- 1. The limit of detection was 3.3 × 10- 11 mol L- 1 (S/N = 3). It can be used for the detection of FPT in vegetable samples.

Molecular imprinting technology for next-generation water treatment via photocatalysis and selective pollutant adsorption

With the growth of industry and agriculture, contaminants such as pharmaceuticals, pesticides, phenolic residues, heavy metals, among others, have been caused serious pollution of water bodies and soil, so it is very urgently needed to find highly efficacious and cost-effective materials to remove these pollutants from environment. Owing to their low molecular weight, not easily degraded and long-term presence in the aquatic environment, super-stable mineralization effect, easily modifiable surfaces, and anion intercalation properties, molecular imprinted polymers (MIPs) present unique advantages in the removal of emerging pollutants. It is very critical to understand the mechanism of pharmaceuticals, pesticides, phenolic residues, dyes, and heavy metals removal by MIPs for the subsequent design of the adsorbent and photodegradation materials structure. Herein, we discuss the recent advancements in the applications of MIPs in water treatment, with a major focus on their use in adsorption and photocatalysis. The preparation methods and characterization of MIPs intended for water treatment are discussed at the beginning of this review. Then it discusses the potential of MIPs-based nanocomposites for the selective photocatalytic degradation and adsorption of a wide range of pollutants in water. Finally, a summary and the ongoing research efforts in this field is further provided.

Glycan-Imprinted Nanoparticle as Artificial Neutralizing Antibody for Efficient HIV-1 Recognition and Inhibition.

The HIV-1 envelope is a heavily glycosylated class 1 trimeric fusion protein responsible for viral entry into CD4+ immune cells. Developing neutralizing antibodies against the specific envelope glycans is an alternative method for antiviral therapies. This work presents the first-ever development and characterization of artificial neutralizing antibodies using molecular imprinting technology to recognize and bind to the envelope protein of HIV-1. The prepared envelope glycan-imprinted nanoparticles (GINPs) can successfully prevent HIV-1 from infecting target cells by shielding the glycans on the envelope protein. In vitro experiments showed that GINPs have strong affinity toward HIV-1 (Kd = 36.7 ± 2.2 nM) and possess high anti-interference and specificity. GINPs demonstrate broad inhibition activity against both tier 1 and tier 2 HIV-1 strains with a pM-level IC50 and exhibit a significant inhibitory effect on long-term viral replication by more than 95%. The strategy provides a promising method for the inhibition and therapy of HIV-1 infection.

Alkane molecularly imprinted nanofiber membranes used to enhance the diesel degradation process

AbstractCombining molecular imprinting technology with electrostatic spinning technology, a molecularly imprinted nanofiber membrane material with memory and recognition of specific imprinted molecules is thus produced. It has the advantages of high efficiency, reusability, easy amplification, and simple operation. In this study, alkane molecularly imprinted nanofibrous membranes are prepared as a carrier for immobilize Bacillus cereus LY‐1 for the degradation of diesel in oil–water system. The adsorption capacity of the molecularly imprinted material for diesel oil with n‐decyl alcohol as the template molecule reach 120.25 mg g−1, the adsorption capacity of alkane molecularly imprint nanofiber membrane prepared using polyvinyl alcohol (PVA) as the membrane substrate material is 41.37 mg g−1. After 4 days, the immobilized LY‐1 cells eliminate roughly 80.7% of the diesel at a starting concentration of 3 g L−1. The results show that imprinted structures in MINM enhance degradation by loaded microorganisms.

Recent progress in the preparation of theaflavins:" Synthesis, extraction and purification"

AbstractTheaflavins (TFs) are a kind of bioactive compound that formed during the fermentation stage of black tea. TFs play a vital role both in the sensory quality and the biological activity of black tea. However, the complex composition of black tea and the low content of TFs in black tea (0.3%–0.7%) make the technology for the preparation of high‐purity TFs a great challenge. This review provides an updated overview for extracting, synthesizing and purifying of TFs. Molecular imprinting technology, an efficient method for extracting bioactive compounds, will be a promising method for the preparation of TFs with high purity. Overall, this review can provide a scientific basis and technical support for the preparation of TFs with high purity and will be helpful for the in‐depth development and further research of TFs.

Electrochemical detection of caffeine in sports drinks based on molecular imprinting technology

Electrochemical detection of caffeine in sports drinks based on molecular imprinting technology

Study on the Selectivity of Molecular Imprinting Materials Determined through Hydrogen Bonding on Template Molecular Structures of Flavonoids.

Molecular imprinting technology is widely used for the specific identification of compounds, but the selective recognition mechanisms of the same compounds still need to be further studied. Based on differences in hydrogen bond size and orientation, molecularly imprinted polymers (MIPs) were designed to adsorb flavonols with the same parent core and different hydroxyl groups. A surface-imprinted material was designed with silicon dioxide as the carrier, myricetin as the template molecule, and methacrylic acid (MAA) as the functional monomer. Scanning electron microscopy (SEM), Brunauer-Emmett-Teller surface area (BET) analyses, Fourier-transform infrared spectroscopy (FT-IR), and other characterization experiments were carried out. The intrinsic mechanism of the MIPs was also explored. The MIPs showed good adsorption of myricetin and other flavonoids through hydrogen bonding and steric hindrance. The adsorption capacity was 3.12-9.04 mg/g, and the imprinting factor was 1.78-3.37. Flavonoids with different hydroxyl groups in different numbers and directions had different hydrogen bond strengths with functional monomers. R2, R4, and R1 on 2-phenylchromogenone had stronger electronegativity, and the hydroxyl group was also more likely to form and have stronger hydrogen bonds. The hydroxyl negativity and the degree of steric hindrance of flavonoids played a major role in the recognition of molecularly imprinted materials. This study is of great significance for the synthesis of and selection of templates for analogous molecular imprinting materials.

A novel molecularly imprinted photoelectrochemical sensor utilizing Ag/SnO2 for the highly sensitive and selective detection of 2,4-dichlorophenoxyacetic acid

The pervasive use of herbicides in agriculture has necessitated the development of sensitive and selective detection methods for environmental monitoring. In this work, a novel photoelectrochemical sensor based on molecular imprinting technology was engineered to specifically detect 2,4-dichlorophenoxyacetic acid (2,4-D) using an Ag/SnO2 composite. The SnO2 was chosen as the photoelectric material due to its abundant surface defects, excellent thermal stability, and high electron carrier density, which are essential for enhanced photoelectrochemical reactions. The introduction of Ag to the SnO2 matrix exploited the surface plasmon resonance effect to bridge its wide band gap, thereby improving the photoelectric conversion efficiency. This Ag/SnO2 composite was then deposited onto an indium tin oxide (ITO) substrate to utilize its high conductivity and optical transparency, followed by the strategic layering of molecularly imprinted polymers (MIPs) that offer selective recognition sites for 2,4-D. To ensure the robustness of the sensor, a Nafion solution was meticulously applied dropwise, which served to immobilize the MIPs/Ag/SnO2 complex on the ITO surface and enhance the sensor's durability. Under optimized conditions, the sensor exhibited a broad linear detection range from 3 × 10-12 to 3 × 10-5 mol/L and a low detection limit of 1.13 × 10-12 mol/L (S/N = 3). The sensor also demonstrated exceptional performance in the analysis of 2,4-D in complex matrices, such as milk, tap water, and beef, highlighting its potential for practical applications in the accurate monitoring of herbicide contamination. These findings affirm the sensor's superior photoelectrochemical properties and introduce an innovative method for the sensitive detection of 2,4-D in environmental and food samples.

Magnetic Molecularly Imprinted Polymers for Selective Extraction of Aflatoxins from Feeds.

Magnetic molecularly imprinted polymers (MMIPs) have fused molecular imprinting technology with magnetic separation technology, emerging as an innovative material capable of recognizing specific molecules and efficiently separating target substances. Their application to the extraction and purification of mycotoxins has great potential, due to the toxicity and economic impact of these contaminants. In this work, MMIP has been proposed as a sample treatment for the determination of main four aflatoxins (B1, B2, G1 and G2) in pig feed. The MMIP was formed through the integration of magnetic material (Fe3O4) with commercial molecularly imprinted polymers, avoiding the synthesis step and, therefore, simplifying the process. The analyses were carried out by high-performance liquid chromatography with fluorescence detection and the method was validated and limits of quantification (LOQs) between 0.09 and 0.47 ng/g were obtained, below the allowed or recommended levels by the European Union. Repeatability and intermediate precision showed relative standard deviations lower than 10% in all cases and trueness ranged from 92 to 111%. Finally, the proposed method was applied to 31 real pig feed samples, detecting aflatoxins with concentrations between 0.2 and 3.2 ng/g.

Methylene blue-assisted molecularly-imprinted film modified nitrogen and sulfur co-doped molybdenum carbide for simultaneous electrochemical determination of two hepatotoxic drugs.

A novel electrochemical sensor with a dual-template molecular imprinting technology was fabricated for the simultaneous detection of paracetamol (PAR) and isoniazid (INZ). The sensor was constructed using nitrogen and sulfur co-doped molybdenum carbide (N, S@Mo2C) and a thin layer of electro-polymerized methylene blue was applied onto the surface of the N, S@Mo2C. The electrochemical sensor demonstrated remarkable analytical efficiency for the concurrent PAR and INZ quantification under optimal circumstances. The system achieved an exceptionally low limit of detection (S/N = 3) of 3.7 nM for PAR, with a concentration range of 0.013 and 140 µM. ALOD of7.6 nM was attained for INZ, with a linear range between 0.025 and 140 µM. Furthermore, the platform's selectivity was evaluated using differential pulse voltammetry (DPV). The designed platform successfully detected PAR and INZ in authentic samples with recoveries varying between 98.3% and 104.9%. The relative standard deviations (RSD) for these measurements ranged from 2.7 to 4.0%, demonstrating that the proposed sensor is extremely stable, repeatable, and reproducible. These promising results suggest that the sensor holds potential for the detection of various (bio) molecules, paving the way for future applications in sensing fields.

Fabrication of Cholesterol‐Imprinted Microspheres‐Based Metal‐Chelating Monomer for Cholesterol Recognition from Serum

AbstractCholesterol is an essential lipid molecule associated with various physiological and pathological processes in the human body. Elevated cholesterol levels are correlated with several diseases, such as atherosclerosis, making cholesterol a critical biomarker for health monitoring. Molecular imprinting technology was selected to fabricate cholesterol imprinted microsphere (CHOL‐IP). This approach creates tailor‐made binding sites within polymer matrices for capturing cholesterol. However, the limited functional group in steroid derivative pose a challenge for the imprinting strategy. In this study, we successfully synthesized CHOL‐IP using a metal chelating monomer, N,N′‐vinylbenzyl iminodiacetic acid (VBIDA), in conjunction with copper (II) ions. The metal coordination approach facilitated strong binding forces, resulting in improved stability and specificity of the molecularly imprinted polymer (MIP). The synthesized CHOL‐IP was tested with pooled human serum samples containing cholesterol, HDL, and LDL. The CHOL‐IP exhibited significantly higher binding efficiency towards these compounds compared to the control polymer (CP). The application of a metal‐chelating functional monomer in the synthesized CHOL‐IP revealed the potential for enhancing its strong binding property toward cholesterol. This suggests that CHOL‐IP could be employed in the development of a cholesterol‐imprinted biosensor, providing an alternative tool for cholesterol analysis in medical detection applications.

Mycotoxins-Imprinted Polymers: A State-of-the-Art Review.

Mycotoxins are toxic metabolites of molds which can contaminate food and beverages. Because of their acute and chronic toxicity, they can have harmful effects when ingested or inhaled, posing severe risks to human health. Contemporary analytical methods have the sensitivity required for contamination detection and quantification, but the direct application of these methods on real samples is not straightforward because of matrix complexity, and clean-up and preconcentration steps are needed, more and more requiring the application of highly selective solid-phase extraction materials. Molecularly imprinted polymers (MIPs) are artificial receptors mimicking the natural antibodies that are increasingly being used as a solid phase in extraction methods where selectivity towards target analytes is mandatory. In this review, the state-of-the-art about molecularly imprinted polymers as solid-phase extraction materials in mycotoxin contamination analysis will be discussed, with particular attention paid to the use of mimic molecules in the synthesis of mycotoxin-imprinted materials, to the application of these materials to food real samples, and to the development of advanced extraction methods involving molecular imprinting technology.

Basic Electrochemistry Meets Molecular Recognition: Hands-On Experiment of Cortisol Detection Using Carbon Paste Electrode Prepared by Molecular Imprinting Technology for Undergraduates

Basic Electrochemistry Meets Molecular Recognition: Hands-On Experiment of Cortisol Detection Using Carbon Paste Electrode Prepared by Molecular Imprinting Technology for Undergraduates

A SERS-assisted 3D organotypic microfluidic chip for in-situ visualization and monitoring breast cancer extravasation process

Extravasation, as one of the key steps in cancer metastasis, refers to the process where tumor cells escape the bloodstream by crossing the vascular endothelium and invade the targeted tissue, which accounts for the low five-year survival rate of cancer patients. Understanding the mechanism of cancer metastasis and inhibiting extravasation are crucial to improve patient prognosis. Here, a 3D organotypic microfluidic chip combined with SERS-based protein imprinted nanomaterials (SPINs) was proposed to study the extravasation process in vitro. The chip consists of a collagen gel channel and a vascular channel where human vein endothelial cells (HUVECs) and breast cancer cells are injected sequentially to induce extravasation. By comparing two subtypes of breast cancer cells (MCF-7 and MDA-MB-231), we successfully observed the difference in extravasation capabilities between two kinds of cells through fluorescence imaging. Meanwhile, thanks to the high specificity of molecular imprinting technology and the high sensitivity of surface enhanced Raman scattering (SERS), SPINs were utilized to analyze the concentration of several cancer secretions (interleukin-6 and interleukin-8) in complex biological fluid in real-time. Further, our model showed that downregulation of secretions by therapeutic drugs can inhibit the extravasation of breast cancers. This microfluidic model may pave the way for the fundamental research of the cancer metastasis and evaluating the therapeutic efficacy of potential drugs.

A More Efficient Method for Preparing a MIP-CQDs/ZnO1-x Photodegradant with Highly Selective Adsorption and Photocatalytic Properties.

The application of semiconductor photocatalysts in wastewater treatment always has a drawback, which is the lack of selectivity for pollutants, but molecular imprinting technology (MIT) is a remarkable method for preparing highly selective adsorbents for low concentration target pollutants. Up to now, the research of molecular imprinting materials has mainly focused on organic polymers, and there has been little research on inorganic molecular imprinting materials. In the present work, we introduced carbon quantum dots (CQDs) into the flower-like hierarchical ZnO to prepare photocatalysts CQDs/ZnO. Further, with ciprofloxacin (CIP) as the template molecule, a molecular imprinting material MIP-CQDs/ZnO1-x was prepared by introducing both oxygen vacancies and imprinted cavities into CQDs/ZnO by the hydrothermal calcination method. It can not only increase the concentration of oxygen vacancies and broaden the light absorption range of zinc oxide without changing the crystal form of ZnO but also make it have the characteristics of preferential adsorption and degradation of CIP during the degradation process. Under the synergistic effect of CQDs, oxygen vacancies, and molecularly imprinted cavities, the molecularly imprinted material exhibits excellent photocatalytic and selective adsorption performance.

Enhanced molecular recognition with longer chain crosslinkers in molecularly imprinted polymers for an efficient separation of TR active substances.

Molecular imprinting technology has been widely studied as a technique to obtain molecular recognition by artificial means. Selecting functional monomers or polymerization conditions plays a key role to optimize molecularly imprinted polymer (MIP) synthesis. To date, there have been few reports well exploiting the effect of crosslinkers. Here, in this study, we synthesized the MIPs using poly(ethyleneglycol) dimethacrylate with different units of ethylene oxide (n = 1 to 23) as crosslinkers to observe the molecular recognition abilities. The MIPs were attached to the surface of mono-dispersed polymer beads. The obtained spherical MIPs and non-imprinted polymers were filled in a column for high performance liquid chromatography. Then the retention selectivity toward TR active substances was evaluated. The result revealed that the recognition ability did not improve regardless of the amount of ethylene oxide. With the crosslinker (n = 9), extremely high retention selectivity was observed, which provides at most around ten times as large imprinting factors in comparison with other MIPs. Interestingly, we obtained the highest recognition ability at around polymerization temperature from the evaluation of the recognition ability toward temperature shift using the MIP (n = 9). In general, hydrogen bonding based on MIPs provides high recognition ability at low temperature, whereas, this study indicates that the use of flexible crosslinkers may enable the synthesis of MIPs that precisely memorize the conditions of polymerization. Lastly, we simultaneously analyzed the TR active substances using the column filled with MIPs (n = 9). The result showed relatively linear correlation between the retention strength of each substance and phycological activity toward TR obtained by yeast assay. Therefore, we can conclude that an induced fit like the receptor emerged by constructing the flexible molecular recognition field.