Teamed Boronate Affinity-Functionalized Zn-MOF/PAN-Derived Molecularly Imprinted Hollow Carbon Electrospinning Nanofibers for Selective Adsorption of Shikimic Acid

Highly sensitive and selective electrochemical detection of catechol using surface molecularly-imprinted film integrated with ratiometric indicator displacement assay

Catechol (CC) is an important environmental pollutant due to its toxicity, non-degradability and widespread distribution. The rapid, sensitive, and selective detection of CC remains a challenging task owing to the coexistence of multiple phenolic pollutants with similar structures and properties in the environment. This article proposed an electrochemical sensing system that combined a molecularly imprinted sensing interface and ratiometric indicator displacement assay (IDA) for sensitive and selective detection of CC. A unique carbon nanotubes (CNTs) interpenetrating ZIF-8 material (CNT@ZIF-8) was successfully prepared and utilized as a support for surface molecular imprinting of CC. As a substrate material, CNT@ZIF-8 increased the electroactive surface area of the electrode, improved electronic conductivity, and promoted the bonding stability of molecularly imprinted polymer (MIP) film on the electrode. The developed sensing interface exhibited excellent adsorption affinity, enrichment ability, and signal transduction ability towards CC. On this basis, a novel IDA method based on ratiometric electrochemical signals was developed using epinephrine (EP) as a competitive indicator. The proposed electrochemical sensing platform had a wide linear range of 1-1000 μM with a detection limit of 0.23 μM and exhibited high anti-interference ability, good repeatability, superior regenerability, and long-term stability. The sensing system was applied to the analysis of CC in tap water and green tea samples, with recoveries of 94.4 %-104 % and 95.7 %-106.7 %, respectively, demonstrating broad practical application prospects. This study not only provides a promising conductive material for surface molecular imprinting and electrochemical sensing but also offers a reliable strategy for the electrochemical detection of CC.

Construction of Brönsted sites on pyrite surface via plasma technology for efficient hydrolysis of microcystins-LR

Enhancing the catalytic hydrolysis efficiency of microcystins (MCs) at ambient temperature has been a persistent challenge in water treatment. We employed N2/low-temperature plasma technology to modify the surface of natural pyrites (NP), and the resulting nitrogen-modified pyrites (NPN) with a nanorod structure and new Fe-Nx sites are more efficient for the hydrolysis of microcystins-LR (MC-LR). Kinetic experiments revealed that NPN exhibited significantly higher hydrolysis activity (kobs = 0.1471 h-1) than NP (0.0914 h-1). Liquid chromatography-mass spectrometry (LC/MS) for the intermediates produced by hydrolyzing MC-LR, in situ attenuated total reflectance Fourier transform infrared spectroscopy (in situ ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) analysis unfolded that the Fe and N atoms of Fe-Nx sites on the surface act of NPN as Lewis acid and Brönsted basic respectively, selectively breaking amide bond on MC-LR molecule. This study demonstrates the effectiveness of plasma technology in modifying mineral materials to enhance their catalytic activity, providing a new method for eliminating MCs in practical water treatment.

Utilizing electrospun molecularly imprinted membranes for food industry: Opportunities and challenges

Molecularly imprinted polymers (MIPs) have been widely studied in environmental protection and food industry, owing to their excellent specific recognition and structural stability. However, MIPs prepared by conventional methods suffer from low adsorption capacity and slow mass transfer rate. To date, the combination of electrostatic spinning technology and molecular imprinting technology has been proposed to prepare molecularly imprinted membranes (MIMs) with specific recognition capability, and has shown great attraction in the separation and detection of food additives, as well as the extraction and release of active ingredients. In recent years, MIPs and electrostatic spinning technologies have been investigated and evaluated. However, there is no review of electrostatically spun MIMs for food field. In this review, we focus on the fabrication methods and applications of electrostatically spun MIMs in the food, discuss the challenges in practical food applications, and emphasize the promising applications of electrostatically spun MIMs in food field.

The preparation of a boronate affinity-based controlled oriented imprinting coating on a silica nanoparticle surface for the separation and purification of shikimic acid in herbal medicine

Shikimic acid (SA) is one of the most effective drugs against the A (H1N1) virus and has high medicinal value. Additionally, it has the ability to generate non-toxic herbicides and antimicrobial medications. The extraction from plants has proven to be the main route of production of SA with economic benefits and environmental efficiency. Therefore, it is necessary to perform purification of SA from these herbal medicines before quantifying it. In this study, researchers employed a boronate affinity-based controlled oriented surface imprinting technique to produce molecularly imprinted polymers (MIPs) as highly effective solid phase extraction (SPE) adsorbents for the isolation and purification of SA. 3-Fluoro-4-formylphenylboronic acid functionalized silica nanoparticles were used as supporting materials for immobilizing SA. Poly(2-anilinoethanol) with a higher hydrophilic domain can be used as an effective imprinting coating. The prepared SA-imprinted silica nanoparticles exhibited several significant results, such as good specificity, high binding capacity (39.06 ± 2.24 mg g-1), moderate binding constant (6.61 × 10-4 M-1), fast kinetics (8 min) and low binding pH (pH 5.0) toward SA. The replication of SA-imprinted silica nanoparticles was deemed satisfactory. The SA-imprinted silica nanoparticles could be still reused after seven adsorption-desorption cycles, which indicated high chemical stability. In addition, the recoveries of the proposed method for SA at three spiked level analysis in star aniseed and meadow cranesbill were 96.2% to 109.0% and 91.6% to 103.5%, respectively. The SA-imprinted silica nanoparticles that have been prepared are capable of identifying the target SA in real herbal medicines. Our approach makes sample pre-preparation simple, fast, selective and efficient.

Facile Prepared MOF-OH-PAN Nanofiber for Separation Co(II) from Waste Batteries

Recovering cobalt from waste batteries is crucial for resource recycling and environmental protection. Here, MOF-OH, a Zr-based MOF, was synthesized and merged into a polyacrylonitrile (PAN) matrix to create MOF-OH-PAN nanofibers (NFs). These NFs showed a high cobalt ion adsorption capacity of 33.1 mg/g, retaining over 90% of the capacity after six cycles. The adsorption mechanism involves Co(II) surface diffusion followed by strong bonding with functional groups. This technology enables efficient cobalt recovery from waste batteries, supporting reuse and reducing resource depletion and environmental pollution. The study provides insights into waste battery resource management, highlighting environmental and economic benefits and contributing to green resource recovery and circular economy initiatives.

Fabrication of double imprinted anchor points in cellulose nanocrystals-based hierarchical porous polyHIPEs for selective separation of flavoniods under physiological pH

Previous research had proved that molecular imprinted polymers can be used as separation material for removing Naringin (NRG) from agricultural pomelo wastes effectively. But the adsorption amounts of NRG molecules from traditional MIPs was quite low by using boronic acid as functional monomer because of single affinity interaction. Therefore, we developed the new combination of bifunctional monomers (i.e. low pKa boronate affinity monomer 2,4-difluoro-3-formylphenylboronic acid and dopamine) based on cellulose nanocrystals (CNCs) mixed with polymerized high internal phase emulsion (polyHIPE, PH) through an double layer surface imprinted method. The introduction of polyethylenimine (PEI) can offer abundant anchor units for the growth of more anchor sites to immobilization template molecules. Importantly, largely improved selective adsorption amounts (50.79 μmol g-1), which may be attribute to the fabrication of the uniform growth of double imprinted layers onto the polydopamine (PDA)/boronic acid-based surfaces. In addition, the resulting double recognition molecular imprinted polymers (MIPs) based on hypercrosslinked PH (DR-HCLPH@MIPs) not only exhibited fast adsorption kinetic of NRG molecule, but also possessed excellent selectivity and high adsorption capacities at physiological pH. Meanwhile, the coarse NRG from pomelo waste can be high selectively extracted to 94.74%. Overall, this study provides a versatile approach for fabrication of the sandwich-biscuit-like double imprinting layer porous MIPs for precise identification and ultrafast transport separation of NRG from complex samples.

Preparation of lysozyme-imprinted mesoporous Zr-based metal-organic frameworks with remarkable specific recognition

The development of high-performance protein-imprinted materials remains challenging due to defects concerning high mass transfer resistance and non-specific binding, which are crucial for protein purification and enrichment. In this paper, lysozyme-imprinted mesoporous Zr-based MOF (mesoUiO-66-NH2@MIPs) with specific and selective recognition of lysozyme (Lyz) were prepared by surface imprinting technology. In particular, the excellent hydrophilicity mesoporous MOFs (mesoUiO-66-NH2) with a pore size of 10 nm was prepared as a carrier for Lyz immobilization by an auxiliary modulation strategy to regulate the microporous structure of UiO-66-NH2 with the propionic acid solution, enabling massive loading of the macromolecular protein Lyz. The mesoUiO-66-NH2@MIPs reached a maximum saturation adsorption of 206.54 mg g-1 on Lyz in 20 min at 25 °C with an imprinting factor of 2.57 and selection factors of 2.02, 2.34, and 2.45 for cytochrome c (Cyt c), bovine serum albumin (BSA) and bovine hemoglobin (BHb), respectively. More importantly, the mesoUiO-66-NH2@MIPs could specifically recognize Lyz from the mixed protein system. The adsorption capacity of Lyz could still reach 78.55% after 5 cycles with good cyclic regeneration performance. This provides a new research option for developing and applying novel porous MOF in biomolecule imprinting technology and the specific separation of biomolecules.

Precise identification and ultrafast transport of specific molecules with nanofluid-functionalized imprinted membrane

Membrane-based imprinted sites for achieving specific molecule transport and precise recognition have great potential to revolutionize nanofiltration technology. Nonetheless, how to efficiently prepare imprinted membrane structures with accurate identification - ultrafast molecular transport - high stability in mobile phase remains a key issue and serious challenge. Herein, we have developed a dual-activation strategy to constructing nanofluid-functionalized membranes with double imprinted nanoscale channels (NMDINCs), realizing ultrafast transport performance as well as structure&size-exclusion selectivity in allusion to particular compounds. The resultant NMDINCs, founded on principal nanofluid-functionalized construction companied by the boronate affinity sol-gel imprinting systems, illustrated that delicate regulation towards polymerization framework as well as functionalization belonging to distinctive membrane structures was crucial for realizing ultrafast molecules transport combined with prominent molecules selectivity. The synergistic recognition of covalent bonds and non-covalent bonds driven by two functional monomers effectively realized the selective recognition to template molecules, leading to the high selective separation factors of Shikimic acid (SA)/ Para hydroxybenzoic acid（PHA）, SA/ P nitrophenol（PN）and catechol（CL）for 8.9, 8.14 and 7.23, respectively. The dynamic consecutive transport outcomes exhibited that numerous SA-dependent recognition sites could still keep reactivity under pump-driven permeation pressure for appreciable time, forcefully proving the successful construction as to high-efficiency membrane-based selective separation system. It is anticipated that this strategy as to the in situ introduction of nanofluid-functionalized construction into porous membrane would hold great promise in preparing high-intensities membrane-founded discriminating separation systems, which was equipped with prominent consecutive permeability as well as excellent selectivity.

Efficient removal of methylene blue from aqueous solution by ZIF-8-decorated helicoidal electrospun polymer strips

Immobilization of metal-organic frameworks (MOFs) on electrospun products for wastewater treatment has garnered considerable attention in recent years. However, the effect of the overall geometry and surface-area-to-volume ratio of MOF-decorated electrospun architectures on their performances have rarely been investigated. Herein, we prepared polycaprolactone (PCL)/polyvinylpyrrolidone (PVP) strips with helicoidal geometries via immersion electrospinning. By regulating the weight ratio of PCL to PVP, the morphologies and surface-area-to-volume ratios of the PCL/PVP strips could be controlled precisely. Then, the zeolitic imidazolate framework-8 (ZIF-8) for removing methylene blue (MB) from an aqueous solution was immobilized on the electrospun strips, resulting in ZIF-8-decorated PCL/PVP strips. The key characteristics of these composite products, such as adsorption and photocatalytic degradation behavior toward MB in the aqueous solution, were carefully investigated. Owing to the desired overall geometry and high surface-area-to-volume ratio of the ZIF-8-decorated helicoidal strips, a high MB adsorption capacity of 151.6 mg g^-1 was obtained, which is significantly higher than those with conventional electrospun straight fibers. In addition, higher MB uptake rates, higher recycling and kinetic adsorption efficiencies, higher MB photocatalytic degradation efficiencies, and faster MB photocatalytic degradation rates were confirmed. This work provides new insights to improve the performance of existing and potential electrospun product-based water treatment strategies.