Preparation of hollow porous molecularly imprinted and aluminum(III) doped silica nanospheres for extraction of the drugs valsartan and losartan prior to their quantitation by HPLC.

Water compatible hollow porous molecularly imprinted nanospheres (HP-MINs) have been prepared for specific recognition and extraction of the blood pressure regulating drugs valsartan (VAL) and losartan (LOS). All synthetic steps were performed in aqueous medium and without consumption of organic solvents. The morphology and functionality of the materials were characterized by FT-IR, FE-SEM, and TEM techniques. The adsorption and selectivity experiments demonstrate that the HP-MINs possess a high binding capacity, fast kinetics, excellent water dispersibility and remarkable selectivity for VAL and LOS. The HP-MINs were utilized for dispersive solid phase extraction of VAL and LOS prior to their determination by HPLC-UV. Main variables and their interactions on extraction yield were optimized by multivariate analysis with least amount of experiments. Under optimized conditions, the method has a linear response in the 5-2000 µg L-1 concentration range of both VAL and LOS. The limits of detection are 1.5 µg L-1 for VAL and 1.4 µg L-1 for LOS. Graphical abstract Schematic representation of dispersive solid phase extraction (d-SPE) of valsartan (VAL) and losartan (LOS) from urine sample by hollow porous molecularly imprinted nanospheres (HP-MINs).

Magnetic molecularly imprinted polymer for the efficient and selective preconcentration of diazinon before its determination by high-performance liquid chromatography.

A molecularly imprinted polymer was selectively applied for solid-phase extraction and diazinon residues enrichment before high-performance liquid chromatography. Diazinon was thermally copolymerized with Fe3 O4 @polyethyleneglycol nanoparticles, methacrylic acid (functional monomer), 2-hydroxyethyl methacrylate (co-monomer), and ethylene glycol dimethacrylate (cross-linking monomer) in the presence of acetonitrile (porogen) and 2,2-azobisisobutyronitrile (initiator). Then, the imprinted diazinon was reproducibly eluted with methanol/acetic acid (9:1, v/v). The sorbent particles were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The comprehensive study of variables through experimental design showed that the maximum performance was achieved under these conditions: pH 7, 10 mL sample volume, 15 mg sorbent, 10 min vortex time, 5 min ultrasonic time, 200 µL methanol/acetic acid (9:1, v/v) as eluent, and 5 min desorption time. Under optimized conditions, the molecularly imprinted polymer solid-phase extraction method demonstrated a linear range (0.02-5 g/mL), a correlation coefficient of 0.997, and 0.005 g/mL detection limit.

Assessing the greenification potential of cyclodextrin-based molecularly imprinted polymers for pesticides detection.

Cyclodextrins, with their unparalleled attributes of eco-friendliness, natural abundance, versatile utility, and facile functionalization, make a paramount contribution to the field of molecular imprinting. Leveraging the unique properties of cyclodextrins in molecularly imprinted polymers synthesis has revolutionized the performance of molecularly imprinted polymers, resulting in enhanced adsorption selectivity, capacity, and rapid extraction of pesticides, while also circumventing conventional limitations. As the concern for food quality and safety continues to grow, the need for standard analytical methods to detect pesticides in food and environmental samples has become paramount. Cyclodextrins, being non-toxic and biodegradable, present an attractive option for greener reagents in imprinting polymers that can also ensure environmental safety post-application. This review provides a comprehensive summary of the significance of cyclodextrins in molecular imprinting for pesticide detection in food and environmental samples. The recent advancements in the synthesis and application of molecularly imprinted polymers using cyclodextrins have been critically analyzed. Furthermore, the current limitations have been meticulously examined, and potential opportunities for greenification with cyclodextrin applications in this field have been discussed. By harnessing the advantages of cyclodextrins in molecular imprinting, it is possible to develop highly selective and efficient methods for detecting pesticides in food and environmental samples while also addressing the challenges of sustainability and environmental impact.

Nitrogen-doped metal-organic framework derived porous carbon/polymer membrane for the simultaneous extraction of four benzotriazole ultraviolet stabilizers in environmental water.

Benzotriazole ultraviolet stabilizers (BUVSs) that are added to pharmaceutical and personal care products (PPCPs) have raised global concerns because of their high toxicity. An efficient method to monitor its pollution level is urgently imperative. Here, a nitrogen-doped metal-organic framework (MOF) derived porous carbon (UiO-66-NH2/DC) was prepared and integrated into polyvinylidene fluoride mixed matrix membrane (PVDF MMM) as an adsorbent for the first time. The hydrophobic UiO-66-NH2/DC with a pore size of 162 Å exhibited outstanding extraction performance for BUVSs, which solves the problem of difficult enrichment of large-size and hydrophobic targets. Notably, the density functional theory simulation was employed to reveal the structure of the derived carbon material and explored the recognition and enrichment mechanism (synergy of π-π conjugation, hydrogen bond, coordination, hydrophobic interaction and mesoporous channel) of BUVSs by UiO-66-NH2/DC-PVDF MMM. And then, an influential method based on dispersive membrane extraction (DME) coupled with ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed for the simultaneous analysis of four BUVSs in environmental water samples. The validated method benefited from the high sensitivity (the limits of detection within 0.25-1.40 ng/L), accuracy (recoveries of 71.9-102.8% for wastewater) and rapidity (50 min to enrich 9 samples). This study expands the application prospects of porous carbon derived from MOF for sample pretreatment of pollutants in water.

Greenificated Molecularly Imprinted Materials for Advanced Applications.

Molecular imprinting technology (MIT) produces artificial binding sites with precise complementarity to substrates and thereby is capable of exquisite molecular recognition. Over five decades of evolution, it is predicted that the resulting host imprinted materials will overtake natural receptors for research and application purposes, but in practice, this has not yet been realized due to the unsustainability of their life cycles (i.e., precursors, creation, use, recycling, and end-of-life). To address this issue, greenificated molecularly imprinted polymers (GMIPs) are a new class of plastic antibodies that have approached sustainability by following one or more of the greenification principles, while also demonstrating more far-reaching applications compared to their natural counterparts. In this review, the most recent developments in the delicate design and advanced application of GMIPs in six fast-growing and emerging fields are surveyed, namely biomedicine/therapy, catalysis, energy harvesting/storage, nanoparticle detection, gas sensing/adsorption, and environmental remediation. In addition, their distinct features are highlighted, and the optimal means to utilize these features for attaining incredibly far-reaching applications are discussed. Importantly, the obscure technical challenges of the greenificated MIT are revealed, and conceivable solutions are offered. Lastly, several perspectives on future research directions are proposed.

Column packing elimination in matrix solid phase dispersion by using water compatible magnetic molecularly imprinted polymer for recognition of melamine from milk samples.

This paper reports a new variant of sample clean-up procedure based on miniaturized matrix solid phase dispersion (MSPD) combining with water compatible magnetic molecularly imprinted polymers (MMIP) for preconcentration of melamine from milk samples prior high-performance liquid chromatography with UV detection. By employing MMIP as dispersant sorbent matrix interferences could be eliminated completely and the column packing step was interestingly omitted that decreasing in glassware expenditure, labor effort and extraction time which cause improvement of the method performance. In order to investigate the functionality, morphology and magnetic properties of the prepared MMIP, it was fully characterized by FT-IR, VSM, SEM, and TEM. Multivariate optimization was applied as a versatile statistical approach for evaluating the influence of the main variables and their interactions on extraction efficiency. Under optimized conditions, the proposed method exhibited a wide linear response in the concentration range of 250.0-5000.0 µg L-1, satisfactory recoveries for all samples (86.6% ≤), and supreme repeatability (RSD less than 6.3%) were achieved as well. The low limit of detection close to 67.0 µg L-1 implied high ability of proposed method for isolation of melamine from complicate milk sample. These befitting results demonstrated that the developed method is unique in terms of the facility, rapidly and least solvent consumption as well as accurate analysis of melamine at trace levels.

Dummy molecularly imprinted polymers based on a green synthesis strategy for magnetic solid-phase extraction of acrylamide in food samples.

In this work, novel dummy molecularly imprinted polymers (DMIP) with propanamide as a dummy template molecule were prepared based on a green synthesis strategy of less consumption of hazardous/organic reagents and at mild conditions for magnetic solid-phase extraction (MSPE) of acrylamide in biscuit samples, followed by high performance liquid chromatography (HPLC) determination. The resultant DMIP was well characterized by FT-IR, SEM, TEM and VSM, exhibiting uniform nanoscale coreshell structure and good magnetic property in favor of simple rapid separation. Several main variables influencing MSPE efficiency were investigated, including DMIP dosage, sample solution pH, extraction time and desorption solvent; central composite design (CCD) and response surface methodology (RSM) were employed to assist in the MSPE condition optimization with rapidity and reliability. Under optimized conditions, excellent linearity for acrylamide was obtained in the range of 5.0-5000.0 µg kg-1, and low detection and quantification limits were 1.3 µg kg-1 and 4.4 µg kg-1, respectively. The method recoveries at five spiked concentrations were found within 86.0-98.3% with relative standard deviations (RSDs) of 1.2-4.1%. Furthermore, endogenous acrylamide was detected in five different biscuit samples and the RSDs values were lower than 3.3%. The present study suggested promising perspectives of water-compatible eco-friendly DMIP based MSPE-HPLC method for highly effective sample pretreatment and targeted analytes determination in complicated matrices.

Hydrophilic Multitemplate Molecularly Imprinted Biopolymers Based on a Green Synthesis Strategy for Determination of B-Family Vitamins.

A novel green synthesis strategy was proposed for preparation of multitemplate molecularly imprinted biopolymers (mt-MIBP) in aqueous media with less consumption of organic solvents, which were subsequently used as sorbents of ultrasound-assisted dispersive solid-phase extraction (d-SPE) for simultaneous recognition and efficient separation of B-family vitamins in juice samples, followed by high performance liquid chromatography (HPLC) determination. The obtained mt-MIBP was fully characterized by SEM, FT-IR, TEM, and BET. It offered high binding capacity, good selectivity, and fast dynamics toward all the templates. Involved parameters in the d-SPE efficiency such as mt-MIBP mass, sonication time, and eluting/washing solvents' types and volumes were concurrently investigated by central composite design with rapidity and reliability. Under the optimum conditions, the developed mt-MIBP-d-SPE-HPLC method exhibited wide linear range, low limits of detection and quantification (LOQs) within 1.2-5.5 µg L-1 and 4.0-18.4 µg L-1, respectively, and appropriate repeatability (relative standard deviation values below 4.2%, n = 4). The high selectivity of this method makes it suitable for successful monitoring of vitamins in juice samples with satisfactory recoveries of 75.8-92.7%, 81.1-92.5%, and 84.7-93.8% for vitamins riboflavin (B2), nicotinamide (B3), and pyridoxine (B6), respectively. The present study implied highly promising perspectives of water-compatible eco-friendly mt-MIBP for highly effective multiresidue analysis in complicated matrixes.

Hollow porous molecularly imprinted polymer for highly selective clean-up followed by influential preconcentration of ultra-trace glibenclamide from bio-fluid.

In the present work, hollow porous molecularly imprinted polymer (HPMIP) was prepared via adopting a sacrificial support approach using glibenclamide (GB) as template, methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate as cross-linker (EGDMA) and mesoporous MCM-48 nanospheres as support. Owing to a short thickness of the foresaid HPMIP, a suitable steric structure was readily available that lead to fast and effective mass transfer of target analyte to sorbent and consequently supply high binding capacity. After ultrasonic-assisted dispersive solid phase extraction of urine sample, the analyte of interest was quantitatively pre-concentrated and determined by high performance liquid chromatography-ultraviolet detection (HPLC-UV). Influence of factors affecting the extraction efficiency such as sonication time, sample pH, sorbent dosage, and volumes of eluent and washing agents as well as their significant interactions were simultaneously optimized by experimental design methodology. Under optimized conditions, present method has linear response over concentration range of 10.0-3000.0µgL-1 in human urine samples with a satisfactory detection limit close to 3.5µgL-1. The inter-day precisions of the current method (coefficient of variation) are lower than 5%, while recoveries are more than 89.5%.

A highly selective nanocomposite based on MIP for curcumin trace levels quantification in food samples and human plasma following optimization by central composite design.

A selective and rapid method was developed for quantification of curcumin in human plasma and food samples using molecularly imprinted magnetic multiwalled carbon nanotubes (MMWCNTs) which was characterized with EDX and FESEM. The role of sorbent mass, volume of eluent and sonication time on response in solid phase microextraction procedure were optimized by central composite design (CCD) combined with response surface methodology (RSM) using Statistica. Preliminary experiments reveal that among different solvents, methanol:dimethyl sulfoxide (4:1V/V) led to efficient and quantitative elution of analyte. A reversed-phase high performance liquid chromatographic technique with UV detection (HPLC-UV) was applied for detection of curcumin content. The assay procedure involves chromatographic separation on analytical Nucleosil C18 column (250×4.6mm I.D., 5µm particle size) at ambient temperature with acetonitrile-water adjusted at pH=4.0 (20:80, v/v) as mobile phase at flow rate of 1.0mLmin-1, while UV detector was set at 420nm. Under optimized conditions, the method demonstrated linear calibration curve with good detection limit (0.028ngmL-1) and R2=0.9983. The proposed method was successfully applied to biological fluid and food samples including ginger powder, curry powder, and turmeric powder.

Synthesis of lab-in-a-pipette-tip extraction using hydrophilic nano-sized dummy molecularly imprinted polymer for purification and analysis of prednisolone.

A novel pipette-tip based on nano-sized dummy molecularly imprinted polymer (PT-DMIP) assisted by ultrasonication for the effective enrichment and analysis of prednisolone from urine samples was developed. The PT-DMIP cartridge was prepared by packing the dummy molecularly imprinted polymer at the tip of the micropipette. The polymerization used betamethasone (BM) as the dummy template, 3-aminopropyltrimethoxysilane (APTMS) as the functionalized monomer, tetraethyl orthosilicate (TEOS) as the cross-linker and aluminum ion (Al(3+)) as a dopant to produce Lewis acid sites in the silica matrix for metal coordinative interactions with the analyte. Compared to conventional solid phase extraction (SPE), the PT-DMIP is cost-effective, fast, and easy to handle, while the system is very approachable and reduces the consumption of toxic organic solvent. HPLC-UV analysis revealed successful applicability of the sorbent for highly efficient extraction of perdnisolone from urine matrices. The extraction recovery was investigated and optimum conditions were obtained using central composite design. Good linearity for prednisolone in the range of 0.22-220µgL(-1) with regression coefficients of 0.99 reveals high applicability of the method for trace analysis. Under the optimized conditions, the recoveries are 89.0-96.1 with relative standard deviations (RSD) of less than 9.0%.

Synthesis and application of molecularly imprinted nanoparticles combined ultrasonic assisted for highly selective solid phase extraction trace amount of celecoxib from human plasma samples using design expert (DXB) software.

In this work molecular imprinted nanoparticles (MINPs) was synthesized and applied for ultrasonic assisted solid phase extraction of celecoxib (CEL) from human plasma sample following its combination by HPLC-UV. The MINPs were prepared in a non-covalent approach using methacrylic acid as monomer, CEL as template, ethylene glycol dimethacrylate as cross-linker, and 2,2-azobisisobutyronitrile (AIBN) as the initiator of polymerization. pH, volume of rinsing and eluent solvent and amount of sorbent influence on response were investigated using factorial experimental design, while optimum point was achieved and set as 250mg sorbent, pH 7.0, 1.5mL washing solvent and 2mL eluent by analysis of results according to design expert (DX) software. At above specified conditions, CEL in human plasma with complicated matrices with acceptable high recoveries (96%) and RSD% lower than 10% was quantified and estimated. The proposed MISPE-HPLC-UV method has linear responses among peak area and concentrations of CEL in the range of 0.2-2000µgL(-1), with regression coefficient of 0.98. The limit of detection (LOD) and quantification (LOQ) based on three and ten times of the noise of HPLC peaks correspond to blank solution were 0.08 and 0.18µgL(-1), respectively.