Hydrophilic gallic acid–imprinted polymers over magnetic mesoporous silica microspheres with excellent molecular recognition ability in aqueous fruit juices

Quick separation and enrichment of chlorogenic acid and its analogues by a high-efficient molecularly imprinted nanoparticles and evaluation of antioxidant and hypoglycemic activities

Multiple interaction strategy to target was tried to use in the design of surface imprinting polymer. To validate this, active chlorogenic acid, a representative phenolic acid compound existing in many natural products, was selected as the template molecule and a magnetic molecularly imprinted nanoparticles (CGA-MMIPs) was synthesized. The characterizations indicated CGA-MMIPs was 20-50 nm, stable below 229.56 °C and had a saturation magnetic intensity of 17.90 emu/g. The prepared CGA-MMIPs exhibited high adsorption capacity (441.81 mg/g) and fast adsorption equilibrium for chlorogenic acid. It also was easy separation, high selectivity and good reusability, which was successfully used in quick separation of chlorogenic acid from Orthosiphon aristatus and Taraxacum mongolicum and Salvia miltiorrhiza. Moreover, the isolated substances possessed great antioxidant and hypoglycemic activities. These verified the strategy was useful and had huge prospects in the quick separation of chlorogenic acid or other phenolic acid compounds from natural products.

Porogenic Solvents in Molecularly Imprinted Polymer Synthesis: A Comprehensive Review of Current Practices and Emerging Trends

The versatility of molecularly imprinted polymers (MIPs) has led to their integration into applications like biosensing, separation, environmental monitoring, and drug delivery technologies. This diversity of applications has resulted in a plethora of synthesis approaches to precisely tailor the materials' properties to the specific demands. A critical, yet often overlooked, factor in MIP synthesis is the choice of porogen. Porogens play a pivotal role in defining the morphology, surface properties, swelling behavior, and binding efficiencies of the resulting MIPs. While aprotic solvents have traditionally been the standard in molecular imprinting, recent developments have expanded the variety of employed porogens accompanied by notable improvements in MIP performance. Therefore, this review aims to highlight both traditional and emerging types of porogens used in molecular imprinting, their influence on polymer properties and sorption performance, and their application across various sensing and extraction applications.

Synthesis of a pH/temperature bi-response gallic acid magnetic imprinted polymer for extracting natural product from Galla chinensis

A pH/temperature bi-responsive gallic acid magnetic imprinted polymer (PTBG-MIP) was synthesized on a Fe3O4@SiO2@KH570 carrier using methacrylic acid (MAA), p-Vinylphenylboronic acid (p-VPBA), and N-isopropyl-acrylamide (NIPAAm) as complex functional monomers. The density functional theory (DFT) was employed to optimize the molar ratio of multi-functional monomers-template complex, which proved to be an effective tool for predicting complex configuration based on electrostatic potential (ESP) analysis and the lowest binding energy. DFT calculation and analysis determined the optimized molar ratio of 2:1:1:1 for GA-MAA-NIPAAm-p-VPBA, which showed good agreement with experimental results. The PTBG-MIP-4 obtained under the optimized conditions exhibited high pH- and temperature- dependence in rebinding the template, displaying a maximum adsorption capacity (Qe) of 62.26 mg g-1 and a highest selection factor (α) of 5.217. Additionally, the PTBG-MIP-4 exhibited exceptional physicochemical properties encompassing magnetization characteristics, morphology, surface sites distribution, and adsorption performance. The application efficiency of this imprinted composite in the extraction and purification of gallic acid from Galla chinensis was remarkably demonstrated.

Polyethyleneimine in designed nanocomposite based magnetic halloysite nanotubes for extraction and determination of gallic acid in green tea

An innovative and simple nanocomposite denoted as MHNTs@PEI was synthesized for gallic acid (GA) analytical sample pretreatment. Polyethyleneimine (PEI) functionalized was binded onto magnetic halloysite nanotubes (MHNTs) to inhence adsorption capacity. MHNTs@PEI was obtained only through two steps modification (amination and PEI modification). Characterizations showed that there are layers of synthetic PEI on the tubular structure of the material and magnetic spheres on its surface, both indicating successful synthesis of the nanocomposite. Furthermore, the adsorption isotherms and kinetic modeling showed that the Langmuir model and pseudo-first-order model fit the adsorption data, respectively. MHNTs@PEI achieved an adsorption capacity of 158 mg·g-1. Overall, the abundant adsorption sites significantly improved the adsorption performance of the MHNTs@PEI. Regeneration tests demonstrated that the MHNTs@PEI exhibits effective adsorption, even after undergoing five consecutive cycles. Optimization of key parameters (ratio, volume of elution, elution time and frequency) in the process of adsorption and desorption was also conducted. The limit of detection (LOD) and that of the quantification (LOQ) were 0.19 and 0.63 μg·mL-1, respectively, and the recoveries were 95.67-99.43 %. Finally, the excellent magnetism (43.5 emu·g-1) and the adsorption feature of MHNTs@PEI enabled its successful utilization in analytical sample pretreatment through the extraction of GA from green tea.

Development of magnetic dispersive micro-solid phase extraction of four phenolic compounds from food samples based on magnetic chitosan nanoparticles and a deep eutectic supramolecular solvent

A magnetic dispersive micro-solid phase extraction technique (CS@Fe₃O₄-MD-μSPE-DESP) based on magnetic chitosan nanoparticles and a deep eutectic supramolecular solvent was developed and applied to determinations of four phenolic compounds in food samples. To prevent environmental pollution and the introduction of toxic substances, deep eutectic supramolecular solvents (DESPs), which exhibited greater desorption capacities than conventional organic solvents and deep eutectic solvents, were used as novel green eluents for the first time. Some important parameters were screened by the Plackett-Burman method and then further optimized with response surface methodology (RSM). Under the optimal conditions, the proposed method showed excellent methodological indices with linearity over the range 0.1-200.0 µg·mL^-1, R² > 0.9988, extraction recoveries above 94.8 %, and precision (RSD%) below 2.9 %. The established method finishes the process of adsorption and desorption in approximately 3 min and enhances the efficiency for determination of phenolic compounds.

Deep-Eutectic-Solvent-Based Mesoporous Molecularly Imprinted Polymers for Purification of Gallic Acid from Camellia spp. Fruit Shells

To produce antioxidant substances from agricultural waste Camellia spp. fruit shells before their further utilization, gallic acid from five kinds of Camellia spp. fruit shells was separated on specific recognition by deep eutectic solvent molecularly imprinted polymers (DES@MIPs), which were prepared by bulk polymerization using gallic acid as the template and deep eutectic solvents (α-methylacrylic acid and choline chloride) as functional monomers. The optimized DES@MIPs were characterized by scanning electron microscopy, particle size analysis, nitrogen sorption porosimetry, elemental analysis, Fourier transform infrared spectroscopy, and thermal gravimetric analysis. The adsorptive behavior of gallic acid on DES@MIPs was also investigated. The results indicated that DES@MIPs were successfully prepared as mesoporous materials with average pore diameter of 9.65 nm and total pore volume of 0.315 cm³ g⁻¹, and the adsorption behavior was multilayer adsorption and pseudo-second-order kinetics with the saturation adsorptive capacity of gallic acid reaching 0.7110 mmol g⁻¹. Although the content of gallic acid in five fruit shells was quite different, the purification recovery of gallic acid was high, ranging from 87.85–96.75% with a purity over 80%. Thus, the purification of gallic acid from Camellia spp. fruit shells could be realized feasibly using DES@MIPs with favorable economic and environmental benefits.

An Update on the Use of Molecularly Imprinted Polymers in Beta-Blocker Drug Analysis as a Selective Separation Method in Biological and Environmental Analysis

Beta-blockers are antihypertensive drugs and can be abused by athletes in some sport competitions; it is therefore necessary to monitor beta-blocker levels in biological samples. In addition, beta-blocker levels in environmental samples need to be monitored to determine whether there are contaminants from the activities of the pharmaceutical industry. Several extraction methods have been developed to separate beta-blocker drugs in a sample, one of which is molecularly imprinted polymer solid-phase extraction (MIP-SPE). MIPs have some advantages, including good selectivity, high affinity, ease of synthesis, and low cost. This review provides an overview of the polymerization methods for synthesizing MIPs of beta-blocker groups. The methods that are still widely used to synthesize MIPs for beta-blockers are the bulk polymerization method and the precipitation polymerization method. MIPs for beta-blockers still need further development, especially since many types of beta-blockers have not been used as templates in the MIP synthesis process and modification of the MIP sorbent is required, to obtain high throughput analysis.

Sulfonamide-Selective Ambient Mass Spectrometry Ion Source Obtained by Modification of an Iron Sheet with a Hydrophilic Molecularly Imprinted Polymer

We have described a sulfonamide-selective ambient ion source coupled with electrospray ionization mass spectrometry (ESI-MS) for selective extraction and determination of trace sulfonamide antibiotics. It is obtained by modifying an iron sheet with a sulfadiazine-templated hydrophilic molecularly imprinted polymer (SF-HMIP). It behaves as both an online extractor and a MS ion source. Five sulfonamide antibiotics, including sulfamethoxazole (SMZ), sulfamerazine (SMR), sulfisoxazole (SIZ), sulfathiazole (ST), and sulfameter (SMD), were chosen to evaluate SF-HMIP coupled with ESI-MS, which showed good linearity in the range of 0.2-1000 ng/mL with correlation coefficient values (R²) over 0.9946. The limits of detection (LODs) for analysis of pure water and honey were in the range of 0.1-0.2 and 0.2-1.5 ng/mL, respectively. Limits of quantitation (LOQs) for analysis of pure water and honey were in the range of 0.3-0.5 and 1.0-5.0 ng/mL, respectively. The results demonstrated that SF-HMIP combined with ESI-MS could be applied for the direct analysis of five trace sulfonamide compounds in honey and pure water with recoveries ranging from 76 to 129%.

Magnetic molecularly imprinted polymer nanoparticles for the extraction and clean-up of thiamethoxam and thiacloprid in light and dark honey

In this work, new selective and sensitive dual-template molecularly imprinted polymer nanoparticles (MIPs) were synthesized and characterized. Sorbent MIPs were investigated for simultaneous extraction and clean-up of thiamethoxam and thiacloprid from light and dark honey samples. In this study, ultra-high-performance liquid chromatography-tandem mass spectrometry triple-quadrupole (UHPLC-MS/MS) (QQQ) was used to detect and quantify the pesticides. The kinetic model with adsorption kinetics of sorbent was investigated. The optimal adsorption conditions were 80 mg of polymer MIPs, a 30-min extraction time, and a pH of 7. The detection limit (LOD) and the quantification limit (LOQ) varied from 0.045 to 0.070 µg kg^-1 and from 0.07 to 0.10 µg kg^-1, respectively. The intra-day and inter-day precision (RSD, %) ranged from 1.3 to 2.0% and from 8.2 to 12.0%, respectively. The recovery of thiamethoxam and thiacloprid ranged from 96.8 to 106.5% and 95.3 to 104.4%, respectively, in light and dark honey samples.

Preparation of boronate-functionalized surface molecularly imprinted polymer microspheres with polydopamine coating for specific recognition and separation of glycoside template

A facile strategy based on the boronate affinity and polydopamine coating was proposed for the preparation of surface molecularly imprinted polymer microspheres using naringin as the glycoside template. The poly(methacrylic acid-co-methyl methacrylate-co-ethyleneglycol dimethacrylate) microspheres were firstly synthesized as inner cores by suspension polymerization method, and then functionalized with 3-aminophenylboronic acid. The imprinted shell layer was obtained by self-polymerization of dopamine on the surface of boronic acid-functionalized polymer microspheres after reversible immobilization of naringin. The resultant surface molecularly imprinted microspheres showed good imprinting efficiency and recognition specificity toward the template molecule in aqueous environment. The isothermal and kinetic adsorption behaviors of the polymers were investigated. The results showed that the covalent surface imprinted microspheres possessed homogeneous recognition sites, strong adsorption affinity, and rapid rebinding kinetics. In addition, the surface imprinted microspheres were utilized as the sorbents of solid phase extraction to successfully separate and enrich naringin from Citri Grandis extract, and the recovery of naringin in eluting solution reached 84.4%.

Synthesis, characterization, and evaluation of a selective molecularly imprinted polymer for quantification of the textile dye acid violet 19 in real water samples

A molecularly imprinted polymer (MIP) was developed for the determination of acid violet 19 (AV19) dye. The MIP was synthesized by polymerization using 1-vinyl imidazole (functional monomer) and 2,2'-azobis(2-methylpropionitrile) as the radical initiator. The functional monomer was previously selected by computational simulations. The MIP adsorption data could be fitted using the Langmuir model obtained a Q_m value of 6.93 mg g^-1 and 2.84 mg g^-1 for the corresponding non-imprinted polymer (NIP) and the process followed pseudo-second-order kinetics (k₂ 0.2416 mg g^-1 min^-1 MIP). The BET specific surface areas were 229.6 m² g^-1 and 28.6 m² g^-1, to MIP and NIP, respectively. Analyses showed that the material provided excellent selectivity towards acid violet 19 (AV19) when compared to other analytes including Acid Violet 17 (AV17), Tartrazine (TZ), Acid Red 14 (AR14), Patent blue-VF (PBV), Sunset yellow FCF (SY) and Acid Red 1 (AR1). The calculated K_d value for the MIP was 0.116 L g^-1 and the imprinting factor was 2.89. This alternative and effective material for the enrichment, extraction, and determination of acid violet 19 presents in complex real samples was applied using two different rivers water and industrial effluent, with excellent recoveries values ranging between 85% up to 99%.

Magnetic ferroferric oxide and polydopamine molecularly imprinted polymer nanocomposites based electrochemical impedance sensor for the selective separation and sensitive determination of dichlorodiphenyltrichloroethane (DDT)

Dichlorodiphenyltrichloroethane (DDT) is a kind of broad-spectrum insecticides, which is potentially toxic and persistently threatens the safety of environment and food, due to their stability in nature and difficulty to degrade. For the first time, a novel impedance chemical sensor based on magnetic Fe₃O₄ and polydopamine molecularly imprinted polymer magnetic nanoparticles (PDA@Fe₃O₄ MIP MNPs) was designed. Bisphenol A (BPA) and dopamine were used as virtual template molecules and functional monomer for MIP synthesis, respectively. Recognition cavities formed in PDA layers could specifically recognize and effectively adsorb DDT molecules, with the help of virtual templates that had similar molecular structure to DDTs. The as-prepared PDA@Fe₃O₄-MIP MNPs could be used for specific adsorption and efficient extraction of target molecules 4,4'-DDT from food samples. The electrochemical impedance of the PDA@Fe₃O₄-MIP MNPs increased sensitively with the adsorption of 4,4'-DDT, the correlationship between of the electrochemical impedance response and the concentration of 4,4'-DDT were applied in the construction of electrochemical impedance sensors for the determination of 4,4'-DDT. The sensor showed a good linear relationship between the charge transfer resistance (R_ct) and the 4,4'-DDT concentration over a range from 1 × 10^-11 to 1 × 10^-3 mol L^-1 with a detection limit of 6 × 10^-12 mol L^-1. The sensor also exhibited excellent sensitivity and selectivity as well as high stability for the detection of pesticide residues and other environmentally harmful chemicals in various food samples.

Pre-concentration of Zn(II) ions from aqueous solutions using meso-porous pyridine-enrobed magnetite nanostructures

A simple, cheap and efficient method for pre-concentrating and separating Zn(II) ions from aqueous solutions and real samples has been designed. The method was implemented in a prototype featuring interchangeable chromatography-column-like cartridges, filled with meso-porous silica nanostructures, allowing easy exchange of the type and quantity of the sorbent. The adsorbents inside the column are held in place by means of porous polymer nano-fibre membranes. The effects of various parameters on the adsorption of Zn(II) ions from aqueous solutions were investigated. Maximal adsorption (∼99%) was found for Zn(II) ions amongst a mixture of Cu(II), Co(II), Ni(II), Ag(I), Au(III), Pd(II) and Pb(II) in aqueous solution. The procedure was tested for pre-concentrating and determining traces of zinc in real samples of meat, fish and hen marketed in Tehran. A desorption process using 0.5 mol L-1 HCl as eluent, showed ∼97% recovery of the Zn(II) ions adsorbed on the MSMPP sorbent.

Recent Progress of Imprinted Nanomaterials in Analytical Chemistry

Molecularly imprinted polymers (MIPs) are a type of tailor-made materials that have ability to selectively recognize the target compound/s. MIPs have gained significant research interest in solid-phase extraction, catalysis, and sensor applications due to their unique properties such as low cost, robustness, and high selectivity. In addition, MIPs can be prepared as composite nanomaterials using nanoparticles, multiwalled carbon nanotubes (MWCNTs), nanorods, quantum dots (QDs), graphene, and clays. This review paper aims to demonstrate and highlight the recent progress of the applications of imprinted nanocomposite materials in analytical chemistry.

Magnetic Porous Molecularly Imprinted Polymers Based on Surface Precipitation Polymerization and Mesoporous SiO₂ Layer as Sacrificial Support for Efficient and Selective Extraction and Determination of Chlorogenic Acid in Duzhong Brick Tea

Magnetic porous molecularly imprinted polymers (MPMIPs) for rapid and efficient selective recognition of chlorogenic acid (CGA) were effectively prepared based on surface precipitation polymerization using CGA as template, 4-vinylpyridine (4-VP) as functional monomer, and mesoporous SiO₂ (mSiO₂) layer as sacrificial support. A computational simulation by evaluation of electronic binding energy is used to optimize the stoichiometric ratio between CGA and 4-VP (1:5), which reduced the duration of laboratory trials. The porous MIP shell and the rid of solid MIPs by magnet gave MPMIPs high binding capacity (42.22 mg/g) and fast kinetic binding (35 min). Adsorption behavior between CGA and MPMIPs followed Langmuir equation and pseudo-first-order reaction kinetics. Furthermore, the obtained MPMIPs as solid phase adsorbents coupled with high performance liquid chromatography (HPLC) were employed for selective extraction and determination of CGA (2.93 ± 0.11 mg/g) in Duzhong brick tea. The recoveries from 91.8% to 104.2%, and the limit of detection (LOD) at 0.8 μg/mL were obtained. The linear range (2.0–150.0 μg/mL) was wide with R² > 0.999. Overall, this study provided an efficient approach for fabrication of well-constructed MPMIPs for fast and selective recognition and determination of CGA from complex samples.

Rapid Colorimetric Detection of Cartap Residues by AgNP Sensor with Magnetic Molecularly Imprinted Microspheres as Recognition Elements

The overuse of cartap in tea tree leads to hazardous residues threatening human health. A colorimetric determination was established to detect cartap residues in tea beverages by silver nanoparticles (AgNP) sensor with magnetic molecularly imprinted polymeric microspheres (Fe₃O₄@mSiO₂@MIPs) as recognition elements. Using Fe₃O₄ as supporting core, mesoporous SiO₂ as intermediate shell, methylacrylic acid as functional monomer, and cartap as template, Fe₃O₄@mSiO₂@MIPs were prepared to selectively and magnetically separate cartap from tea solution before colorimetric determination by AgNP sensors. The core-shell Fe₃O₄@mSiO₂@MIPs were also characterized by FT-IR, TEM, VSM, and experimental adsorption. The Fe₃O₄@mSiO₂@MIPs could be rapidly separated by an external magnet in 10 s with good reusability (maintained 95.2% through 10 cycles). The adsorption process of cartap on Fe₃O₄@mSiO₂@MIPs conformed to Langmuir adsorption isotherm with maximum adsorption capacity at 0.257 mmol/g and short equilibrium time of 30 min at 298 K. The AgNP colorimetric method semi-quantified cartap ≥5 mg/L by naked eye and quantified cartap 0.1–5 mg/L with LOD 0.01 mg/L by UV-vis spectroscopy. The AgNP colorimetric detection after pretreatment with Fe₃O₄@mSiO₂@MIPs could be successfully utilized to recognize and detect cartap residues in tea beverages.

Polydopamine-Coated Magnetic Molecularly Imprinted Polymers with Fragment Template for Identification of Pulsatilla Saponin Metabolites in Rat Feces with UPLC-Q-TOF-MS

In this work, a modified pretreatment method using magnetic molecularly imprinted polymers (MMIPs) was successfully applied to study the metabolites of an important botanical with ultraperformance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). The MMIPs for glucoside-specific adsorption was used to identify metabolites of Pulsatilla chinensis in rat feces. Polymers were prepared by using Fe₃O₄ nanoparticles as the supporting matrix, d-glucose as fragment template, and dopamine as the functional monomer and cross-linker. Results showed that MMIPs exhibited excellent extraction performance, large adsorption capacity (5.65 mg/g), fast kinetics (60 min), and magnetic separation. Furthermore, the MMIPs coupled with UPLC-Q-TOF-MS were successfully utilized for the identification of 17 compounds including 15 metabolites from the Pulsatilla saponin metabolic pool. This study provides a reliable protocol for the separation and identification of saponin metabolites in a complex biological sample, including those from herbal medicines.

Preparation of polydopamine-coated graphene oxide/Fe3O4 imprinted nanoparticles for selective removal of fluoroquinolone antibiotics in water

Antibiotics in water have recently caused increasing concerns for public health and ecological environments. In this work, we demonstrated polydopamine-coated graphene oxide/Fe₃O₄ (PDA@GO/Fe₃O₄) imprinted nanoparticles coupled with magnetic separation for fast and selective removal of fluoroquinolone antibiotics in water. The nanoparticles were prepared by the self-polymerization of dopamine using sarafloxacin as a template. The imprinted PDA film of 10~20 nm uniformly covered the surface of GO/Fe₃O₄ providing selective binding sites. The nanoparticles showed rapid binding and a large capacity (70.9 mg/g). The adsorption data fitted well the Langmuir and pseudo-second order kinetic equations. The nanoparticles could be easily separated by a magnet following the adsorption and then regenerated by simple washing for repetitive adsorptions. The nanoparticles were successfully used for the removal of fluoroquinolone antibiotics in seawater, with removal efficiencies of more than 95%. The proposed strategy has potentials for efficient removal of antibiotics in environmental water.

Effective synthesis of magnetic porous molecularly imprinted polymers for efficient and selective extraction of cinnamic acid from apple juices

An effective strategy was proposed to prepare novel magnetic porous molecularly imprinted polymers (MPMIPs) for highly selective extraction of cinnamic acid (CMA) from complex matrices. Characterization and various parameters affecting adsorption and desorption behaviors were investigated. Results revealed adsorption behavior between CMA and MPMIPs followed Freundlich equation adsorption isotherm with a maximum adsorption capacity at 4.35mg/g and pseudo-second-order reaction kinetics with equilibrium time at 60min. Subsequently, MPMIPs were successfully used to selectively extract CMA from apple juice with a relatively satisfactory recovery (92.7-101.4%). Coupling with high-performance liquid chromatography and ultraviolet detection (HPLC-UV), the limit of detection (LOD) for CMA was 0.006µg/mL, and the linear range (0.02-10μg/mL) was wide with correlation coefficient at 0.9995. Finally, the contents of CMA in two kinds of apple juices were determined as 0.132 and 0.120μg/mL. Results indicated the superiority of MPMIPs in the selective extraction field.

Electrochemiluminescence Detection of Escherichia coli O157:H7 Based on a Novel Polydopamine Surface Imprinted Polymer Biosensor

In this paper, a facilely prepared electrochemiluminescence (ECL) biosensor was developed for Escherichia coli O157:H7 quantitative detection based on a polydopamine (PDA) surface imprinted polymer (SIP) and nitrogen-doped graphene quantum dots (N-GQDs). N-GQDs with a high quantum yield of 43.2% were synthesized. The uniform PDA SIP film for E. coli O157:H7 was established successfully with a facile route. The dopamine and target bacteria were electropolymerized directly on the electrode. After removal of the E. coli O157:H7 template, the established PDA SIP can selectively recognize E. coli O157:H7. Accordingly, E. coli O157:H7 polyclonal antibody (pAb) was labeled with N-GQDs. The bioconjugation of SIP-E. coli O157:H7/pAb-N-GQDs can generate intensive ECL irradiation with K₂S₂O₈. As a result, E. coli O157:H7 was detected with the ECL sensing system. Under optimal conditions, the linear relationships between the ECL intensity and E. coli O157:H7 concentration were obtained from 10¹ colony-forming units (CFU) mL^-1 to 10⁷ CFU mL^-1 with a limit of detection of 8 CFU mL^-1. The biosensor based on this SIP film was applied in water sample detection successfully. The N-GQD-based ECL analytical method for E. coli O157:H7 was reported for the first time. The sensing system had high selectivity to the target analyte, provided new opportunities for use, and increased the rate of disease diagnosis and treatment and the prevention of pathogens.

Hydrophilic surface molecularly imprinted naringin prepared via reverse atom transfer radical polymerization with excellent recognition ability in a pure aqueous phase

An easy and highly efficient method using hydrophilic surface molecularly imprinted polymers (SMIPs) for the selective recognition of naringin from pure aqueous solution was developed.

Rapid ultrasound-assisted magnetic microextraction of gallic acid from urine, plasma and water samples by HKUST-1-MOF-Fe3O4-GA-MIP-NPs: UV-vis detection and optimization study

Magnetite (Fe₃O₄ nanoparticles (NPs)) HKUST-1 metal organic framework (MOF) composite as a support was used for surface imprinting of gallic acid imprinted polymer (HKUST-1-MOF-Fe₃O₄-GA-MIP) using vinyltrimethoxysilane (VTMOS) as the cross-linker. Subsequently, HKUST-1-MOF-Fe₃O₄-NPs-GA-MIP characterized by FT-IR, XRD and FE-SEM analysis and applied for fast and selective and sensitive ultrasound assisted dispersive magnetic solid phase microextraction of gallic acid (GA) by UV-Vis (UA-DMSPME-UV-Vis) detection method. Plackett-Burman design (PBD) and central composite design (CCD) according to desirability function (DF) indicate the significant variables among the extraction factors vortex (mixing) time (min), sonication time (min), temperature (°C), eluent volume (L), pH and HKUST-1-MOF-Fe₃O₄-NPs-GA-MIP mass (mg) and their contribution on the response. Optimum conditions and values correspond to pH, HKUST-1-MOF-Fe₃O₄-NPs-GA-MIP mass, sonication time and the eluent volume were set as follow 3.0, 1.6mg, 4.0min and 180μL, respectively. The average recovery (ER%) of GA was 98.13% with desirability of 0.997, while the present method has best operational performance like wide linear range 8-6000ngmL^-1 with a Limit of detection (LOD) of 1.377ngmL^-1, limit of quantification (LOQ) 4.591ngmL^-1 and precision (<3.50% RSD). The recovery of GA in urine, human plasma and water samples within the range of 92.3-100.6% that strongly support high applicability of present method for real samples analysis, which candidate this method as promise for further application.

Boronate affinity-based surface molecularly imprinted polymers using glucose as fragment template for excellent recognition of glucosides

Rapid and efficient extraction of bioactive glycosides from complex natural origins poses a difficult challenge, and then is often inherent bottleneck for their highly utilization. Herein, we propose a strategy to fabricate boronate affinity based surface molecularly imprinted polymers (MIPs) for excellent recognition of glucosides. d-glucose was used as fragment template. Boronic acid, dynamic covalent binding with d-glucose under different pH conditions, was selected as functional monomer to improve specificity. Fe3O4 solid core for surface imprinting using tetraethyl orthosilicate (TEOS) as crosslinker could control imprinted shell thickness for favorable adsorption capacity and satisfactory mass transfer rate, improve hydrophilicity, separate easily by a magnet. Model adsorption studies showed that the resulting MIPs show specific recognition of glucosides. The equilibrium data fitted well to Langmuir equation and the adsorption process could be described by pseudo-second order model. Furthermore, the MIPs were successfully applied for selective extraction of three flavonoid glucosides (daidzin, glycitin, and genistin) from soybean. Results indicated that selective extraction of glucosides from complex aqueous media based on the prepared MIPs is simple, rapid, efficient and specific. Moreover, this method opens up a universal route for imprinting saccharide with cis-diol group for glycosides recognition.

Amine bridges grafted mesoporous silica, as a prolonged/controlled drug release system for the enhanced therapeutic effect of short life drugs

Hybrid mesoporous silica SBA-15, with surface incorporated cross-linked long hydrophobic organic bridges was synthesized using stepwise synthesis. The synthesized materials were characterized by elemental analysis, infrared spectroscopy, nuclear magnetic resonance spectroscopy, nitrogen adsorption, X-rays diffraction, thermogravimetry and scanning and transmission electron microscopy. The functionalized material showed highly ordered mesoporous network with a surface area of 629.0m²g^-1. The incorporation of long hydrophobic amine chains on silica surface resulted in high drug loading capacity (21% Mass/Mass) and prolonged release of ibuprofen up till 75.5h. The preliminary investigations suggests that the synthesized materials could be proposed as controlled release devices to prolong the therapeutic effect of short life drugs such as ibuprofen to increase its efficacy and to reduce frequent dosage.