Search Results (157)

Molecularly imprinted membranes (MIMs) have demonstrated tremendous potential in the field of high-efficiency separation due to their specific molecular recognition capabilities. This review aims to elucidate the underlying mechanisms governing MIMs’ performance and, moving beyond traditional classification frameworks, systematically reconstructs the classification system for MIMs from the perspectives of the spatial distribution of imprinted sites, the chemical topology of the matrix, and mass transfer kinetics. The article focuses on the decisive influence of key physical parameters such as pore size, specific surface area, hydrophilicity/hydrophobicity, and swellability on separation efficiency. It provides an in-depth analysis of the spatial matching between pore size and target molecules, the nonlinear relationship between specific surface area and adsorption capacity, and the mechanisms by which mechanical strength and swelling behavior constrain the long-term stability of the membranes. Addressing the common bottlenecks faced by MIMs “high mass transfer resistance and poor accessibility of recognition sites” this paper critically summarizes cutting-edge morphological optimization strategies, such as multi-level pore construction, nanocomposite reinforcement, and surface topological engineering, aiming to elucidate how microstructural regulation can achieve a synergistic enhancement of both high throughput and high selectivity. Finally, by reviewing breakthroughs in MIMs applications for biomedical extraction and environmental pollutant remediation, this review not only clarifies the principles governing material suitability across different scenarios but also provides a systematic technical reference for the development of next-generation, high-performance, industrial-scale MIMs. Full article

Molecular imprinting is a powerful strategy for fabricating synthetic materials with selective recognition toward specific biomolecules. In this work, molecularly imprinted (MIM) membranes based on poly (ethylene-co-vinyl alcohol) (EVAL) were developed for selective protein recognition and conformational modulation using α-amylase as a model template. Membranes were prepared by phase inversion, generating porous structures suitable for mass transport and adsorption. Template extraction, measured using UV–Vis spectroscopy, showed a rapid and effective removal of α-amylase while preserving membrane morphology, as confirmed by SEM. FTIR-ATR and chemical imaging confirmed template removal from the membrane and a uniform surface distribution of rebound α-amylase after successive template incubation. Rebinding experiments showed a concentration-dependent uptake of α-amylase and an apparent saturation trend at higher concentrations. Selectivity tests using bovine serum albumin as an analog confirmed preferential recognition of α-amylase. Enzymatic assays showed partial recovery of catalytic activity after rebinding of thermally denatured α-amylase, indicating that imprinted cavities may promote protein conformational reorganization. These results highlight the potential of EVAL-based imprinted membranes as biomimetic platforms for selective protein recognition and functional modulation. Full article

Protein molecularly imprinted polymers (MIPs), as artificial antibodies, are promising for protein separation due to their low cost, easy preparation, and high stability, but their performance is limited by poor mass transfer, imprecise imprinting, and single interaction modes. Herein, dendritic mesoporous silica nanoparticles (DMSNs) were used as the support, and a self-designed multifunctional poly(ionic liquid) macromonomer (p(VIMCD-co-VAIM-co-VSIM-co-VVIM)) served as the functional monomer to achieve directional anchoring of cytochrome C (Cyt-C). Surface-imprinted microspheres (DMSNs@MPS@PILs-MIPs) were prepared via free-radical copolymerization for Cyt-C recognition. The DMSNs possessed interconnected mesoporous channels, good dispersibility, an average particle size of ~80 nm, and a specific surface area of 267.97 m²/g. Ionic liquid monomers were synthesized via alkylation, and the macromonomer was constructed through a two-step method. Molecular dynamics simulations and spectroscopic characterization revealed the macromonomer-stabilized Cyt-C conformation, with interactions dominated by van der Waals forces. The DMSNs@MPS@PILs-MIPs featured a thin imprinted layer (~5 nm) to reduce mass-transfer resistance. Adsorption studies showed Cyt-C adsorption followed Langmuir and pseudo-second-order models, with a maximum capacity of 383.14 mg/g and an imprinting factor of 2.17. Only 12% capacity loss occurred after repeated cycles, indicating robust regeneration stability. This study provides a feasible strategy for constructing protein surface-imprinted polymers based on multifunctional synergistic interactions and conformational stabilization. Full article

Molecularly imprinted polymers (MIPs) are widely employed for selective adsorption of target molecules in sensing and separation applications. The architecture of MIP films can influence adsorption behavior, interfacial stability, and reusability, yet systematic investigations of these effects are limited. This study aimed to evaluate how different polypyrrole (PPy) MIP film architectures affect the adsorption, stability, and regeneration characteristics of geraniol-imprinted layers on gold electrodes. Geraniol-imprinted and non-imprinted PPy films were electropolymerized onto quartz crystal microbalance (QCM) substrates. Two film architectures were compared: (i) a single-layer geraniol-imprinted PPy film, and (ii) a double-layer film consisting of a non-imprinted PPy underlayer followed by a geraniol-imprinted layer. Film characterization was performed using cyclic voltammetry (CV) and electrochemical quartz crystal microbalance (EQCM) measurements. Adsorption–desorption cycles were conducted to assess mass uptake, signal stability, and regeneration performance. EQCM analysis revealed that the double-layer architecture exhibited enhanced frequency signal stability during repeated adsorption–desorption cycles compared to single-layer films, suggesting a stabilizing effect of the underlying non-imprinted PPy layer at the electrode interface. Geraniol-imprinted films demonstrated significantly higher mass uptake than non-imprinted controls, confirming the sensitivity provided by molecular imprinting. Single-layer films showed more variability in signal response and less consistent regeneration performance. The architecture of MIP films significantly affects adsorption behavior, stability, and regeneration on electrode surfaces. Incorporating a non-imprinted PPy underlayer can improve signal reproducibility and enhance the robustness of MIP-based sensing interfaces. These findings provide guidance for the rational design of MIP coatings for electrochemical sensors and QCM-active platforms. Full article

A surface plasmon resonance (SPR) sensor utilizing a molecularly imprinted polymer (MIP) film as the recognition element was developed for the selective detection of the non-steroidal anti-inflammatory drug ibuprofen (IBU). The molecularly imprinted film on the SPR sensor chip was prepared via photo-initiated in situ polymerization, enabling specific recognition of IBU molecules. Experimental results indicate that the SPR sensor can specifically identify IBU in solution, with a detection limit of 10⁻¹¹ mol/L for ibuprofen. Within the concentration range of 10⁻¹¹ to 10⁻⁴ mol/L, a linear relationship was observed between the SPR signal and the negative logarithm of the IBU concentration. This method offers the advantages of a low detection limit, wide detection range, and high selectivity, making it suitable for trace detection of IBU in solutions. Full article

The integration of molecular imprinting technology with electrochemical methods has become fundamental in the development of next-generation sensors. This study explores two different strategies for developing a dopamine-based molecularly imprinted polymer (MIP) for the electrochemical sensing of levofloxacin. In the first case, the MIP is developed by electropolymerization on a screen-printed carbon electrode (SPCE) surface using cyclic voltammetry, while in the second, the MIP is obtained by an oxidation process, and the resulting dispersion is drop-cast on the SPCE surface. The same approach is used for a non-imprinted polymer. The physicochemical properties of the synthesized materials and the surface morphology of the modified electrodes are investigated by several techniques. Differential pulse voltammetry is used to evaluate the performance of the modified electrodes, assessing their linear concentration range, limit of detection, and limit of quantification, together with repeatability and selectivity. MIP-based SPCEs obtained with these two fabrication strategies exhibited comparable imprinting factor values and linear concentration ranges, along with comparable limits of detection and quantification. The MIP-based SPCE obtained by electropolymerization showed greater repeatability, whereas the MIP-based SPCE produced by drop-casting provided higher sensitivity in levofloxacin detection. Full article

In this work, we report the development of a highly sensitive optical sensor for the detection of cardiac troponin I (cTnI), a key biomarker for early-stage myocardial infarction diagnosis. The sensor combines castor oil-derived biomimetic receptors, called GreenNanoMIPs and prepared via the molecular imprinting technology using as a template an epitope of cTnI (i.e., the NR10 peptide), with a portable multimode plastic optical fiber surface plasmon resonance (POF-SPR) transducer. For sensing, gold SPR chips were functionalized with GreenNanoMIPs as proven by refractive index changes and confirmed by means of XPS. Binding experiments demonstrated the cTnI_nanoMIP-SPR sensor’s ability to detect both the NR10 peptide epitope and the full-length cTnI protein within minutes (t = 10 min), with high sensitivity and selectivity in buffer and serum matrices. The cTnI_nanoMIP-SPR showed an LOD of 3.53 × 10⁻¹⁵ M, with a linearity range of 1 pM–100 pM, outperforming previously reported sensor platforms and making it a promising tool for early-stage myocardial infarction detection. Full article

In recent years, polymer-mediated signal amplification has drawn wide attention in bioelectronic sensing. With the rapid progress of biosensing and flexible electronics, polymers with excellent electron–ion transport properties, tunable molecular structures, and good biocompatibility have become essential materials for enhancing detection sensitivity and interfacial stability. However, current sensing systems still face challenges such as signal attenuation, surface fouling, and multi-component interference in complex biological environments, limiting their use in medical diagnosis and environmental monitoring. This review summarizes the progress of conductive polymers, molecularly imprinted polymers, hydrogels, and composite polymers in medical diagnosis, food safety, and environmental monitoring, focusing on their signal amplification mechanisms and structural optimization strategies in electronic transport regulation, molecular recognition enhancement, and antifouling interface design. Overall, polymers improve detection performance through interfacial electronic reconstruction and multidimensional synergistic amplification, offering new ideas for developing highly sensitive, stable, and intelligent biosensors. In the future, polymer-based amplification systems are expected to expand in multi-parameter integrated detection, long-term wearable monitoring, and in situ analysis of complex samples, providing new approaches to precision medicine and sustainable environmental health monitoring. Full article

To develop molecularly imprinted polymer (MIP)-based biosensors effectively, it is necessary to evaluate the potential adsorption of materials onto the electrode surface. Therefore, we investigated the adsorption of geraniol and pyrrole and compared them. In addition to determining adsorption constants, particular focus was placed on adsorption mechanisms, as they directly influence monolayer or multilayer formation, template removal efficiency, and the selectivity of the final imprinted structure. To achieve this, we employed various electrochemical methods, including cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and quartz crystal microbalance (QCM) measurements. Measurements were repeated to ensure reliability. The findings were used to calculate adsorption constants using the Langmuir equation. Geraniol and pyrrole showed adsorption constants of 21.5 L/mol and 31.7 L/mol, respectively, indicating strong molecular interactions. These results indicate strong interactions between the two molecules, suggesting that geraniol influences electrode polymerization. This led to the importance of proper surface preparation, evaluation of analyte–monomer interactions, and the opportunity to reuse materials. Full article

Ensuring food safety and quality has become increasingly critical due to the complexities introduced by globalization, industrialization, and extended supply chains. Traditional analytical methods for food quality control, such as chromatography and mass spectrometry, while accurate, face limitations including high costs, lengthy analysis times, and limited suitability for on-site rapid monitoring. Electrochemical sensors integrated with molecularly imprinted polymers (MIPs) have emerged as promising alternatives, combining high selectivity and sensitivity with portability and affordability. MIPs, often termed ‘plastic antibodies,’ are synthetic receptors capable of selective molecular recognition, tailored specifically for target analytes. This review comprehensively discusses recent advancements in MIP-based electrochemical sensing platforms, highlighting their applications in detecting various food quality markers. It particularly emphasizes the detection of antioxidants—both natural (e.g., vitamins, phenolics) and synthetic (e.g., BHA, TBHQ), artificial sweeteners (e.g., aspartame, acesulfame-K), colorants (e.g., azo dyes, anthocyanins), traditional contaminants (e.g., pesticides, heavy metals), and toxicants such as mycotoxins (e.g., aflatoxins, ochratoxins). The synthesis methods, including bulk, precipitation, surface imprinting, sol–gel polymerization, and electropolymerization (EP), are critically evaluated for their effectiveness in creating highly selective binding sites. Furthermore, the integration of advanced nanomaterials, such as graphene, carbon nanotubes, and metallic nanoparticles, into these platforms to enhance sensitivity, selectivity, and stability is examined. Practical challenges, including sensor reusability, regeneration strategies, and adaptability to complex food matrices, are addressed. Finally, the review provides an outlook on future developments and practical considerations necessary to transition these innovative MIP electrochemical sensors from laboratory research to widespread adoption in industry and regulatory settings, ultimately ensuring comprehensive food safety and consumer protection. Full article

Elevated levels of homocysteine (Hcy) are associated with various pathological conditions including atherosclerosis, hypertension, and cardiovascular diseases. In this work, quantum-dot-based molecularly imprinted hydrogels (QD@MIHs) were developed by integrating L-cysteine-modified ZnS quantum dots (QDs)with highly selective molecular imprinting technology for rapid homocysteine detection. The QD@MIPHs were fabricated using a dual-functional monomer system (acrylamide and methacrylic acid) through surface coating of the Hcy molecularly imprinted polymer gel onto the QDs. Under optimal conditions, the response time of the QD@MIPHs for Hcy detection was 5 min. When the Hcy concentration ranged from 0.1 to 10.0 μM, the fluorescence quenching of the QD@MIHs showed a good linear relationship with Hcy concentration (R² = 0.9972), with a corresponding detection limit of 0.027 μM. In addition, the constructed QD@MIPHs showed no significant response to other interfering substances, demonstrating the high selectivity of the prepared material. Practical sample analysis revealed that the recovery rates of Hcy ranged from 94.34% to 104.1%, with relative standard deviations (RSD, n = 3) between 3.56% and 7.17%. This study provides a novel tool and method for rapid Hcy detection with significant potential in biomedical diagnostics and preventive-healthcare applications. Full article

In this study, we investigate the effect of varying the loading of molecularly imprinted polymer nanoparticles (MIP-NPs) on the morphology and sensing performance of electrospun nanofibres for the selective detection of linalool, a representative plant-emitted monoterpene. The proposed strategy combines two synergistic technologies: molecular imprinting, to introduce chemical selectivity, and electrospinning, to generate high-surface-area nanofibrous sensing layers with tuneable architecture. Linalool-imprinted MIP-NPs were synthesized via precipitation polymerization using methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA), yielding spherical particles with an average diameter of ~135 nm. These were embedded at increasing concentrations into a polyvinylpyrrolidone (PVP) matrix containing multi-walled carbon nanotubes (MWCNTs) and processed into nanofibrous mats by electrospinning. Atomic force microscopy (AFM) revealed that MIP content modulates fibre roughness and network morphology. Electrical sensing tests performed under different relative humidity (RH) conditions showed that elevated humidity (up to 60% RH) improves response stability by enhancing ion-mediated charge transport. The formulation with the highest MIP-NP loading exhibited the best performance, with a detection limit of 8 ppb (±1) and 84% selectivity toward linalool over structurally related terpenes (α-pinene and R-(+)-limonene). These results demonstrate a versatile sensing approach in which performance can be precisely tuned by adjusting MIP content, enabling the development of humidity-tolerant, selective VOC sensors for environmental and plant-related applications. Full article

Nanomaterials’ special features enable their extensive application in chemical and biochemical nanosensors for food assays; food packaging; environmental, medicinal, and pharmaceutical applications; and photoelectronics. The analytical strategies based on novel nanomaterials have proved their pivotal role and increasing interest in the assay of key food components. The choice of transducer is pivotal for promoting the performance of electrochemical sensors. Electrochemical nano-transducers provide a large active surface area, enabling improved sensitivity, specificity, fast assay, precision, accuracy, and reproducibility, over the analytical range of interest, when compared to traditional sensors. Synthetic routes encompass physical techniques in general based on top–down approaches, chemical methods mainly relying on bottom–up approaches, or green technologies. Hybrid techniques such as electrochemical pathways or photochemical reduction are also applied. Electrochemical nanocomposite sensors relying on conducting polymers are amenable to performance improvement, achieved by integrating redox mediators, conductive hydrogels, and molecular imprinting polymers. Carbon-based or metal-based nanoparticles are used in combination with ionic liquids, enhancing conductivity and electron transfer. The composites may be prepared using a plethora of combinations of carbon-based, metal-based, or organic-based nanomaterials, promoting a high electrocatalytic response, and can accommodate biorecognition elements for increased specificity. Nanomaterials can function as pivotal components in electrochemical (bio)sensors applied to food assays, aiming at the analysis of bioactives, nutrients, food additives, and contaminants. Given the broad range of transducer types, detection modes, and targeted analytes, it is important to discuss the analytical performance and applicability of such nanosensors. Full article

This study pioneers the development of a synergistic Ag-doped molecularly imprinted TiO₂ photocatalyst (MIP-Ag-TiO₂) through a multi-strategy engineering approach, integrating molecular imprinting technology with plasmonic metal modification via a precisely optimized sol–gel protocol. Breaking from conventional non-selective photocatalysts, our material features an engineered surface architecture that combines selective molecular recognition sites with enhanced charge separation capabilities, specifically tailored for the targeted degradation of recalcitrant salicylic acid (SA) contaminants. Advanced characterization (XRD, EPR, FT-IR, TEM-EDS) reveals unprecedented structure–activity relationships, demonstrating how template molecule ratios (Ti:SA = 5:1) and calcination parameters (550 °C) collaboratively optimize both adsorption selectivity and quantum efficiency. The optimized MIP-Ag-TiO₂ achieves breakthrough performance metrics: 98.6% SA degradation efficiency at 1% Ag doping, coupled with a record selectivity coefficient R = 7.128. Mechanistic studies employing radical trapping experiments identify a dual •OH/O_2⁻-mediated degradation pathway enabled by the Ag-TiO₂ Schottky junction. This work establishes a paradigm-shifting “capture-and-destroy” photocatalytic system that simultaneously addresses the critical challenges of selectivity and quantum yield limitations in advanced oxidation processes, positioning molecularly imprinted plasmonic photocatalysts as next-generation smart materials for precision water purification. Full article

Malachite green (MG) is a highly toxic dye commonly used in industries and aquaculture, leading to significant environmental contamination and health hazards. Therefore, sensitive and selective detection of MG in real samples is urgently needed. This study presents the development of a molecularly imprinted surface-enhanced Raman spectroscopy (MI-SERS) plasmonic sensor for the rapid and sensitive detection of MG. The sensor consists of a gold nanostar (Au NS) layer as the SERS substrate and an imprinted polydopamine layer containing specific recognition sites for MG. Taking full advantage of the plasmonic effect of SERS and selective recognition capability of imprinted materials, under optimized conditions, the sensor demonstrated high sensitivity, with a detection limit of 3.5 × 10⁻³ mg/L, excellent selectivity against interference from other organic dyes, and robust performance with recoveries of 90.2–114.2% in real seawater samples. The MI-SERS sensor also exhibited good reproducibility, stability, and reusability. These findings suggest that the MI-SERS sensor is a promising tool for real-time monitoring of MG contamination in complicated samples. Full article