scholarly journals A Novel Method for Extraction of Galegine by Molecularly Imprinted Polymer (MIP) Technique Reinforced with Graphene Oxide and Its Evaluation Using Polarography

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
M. Azimi ◽  
M. Ahmadi Golsefidi ◽  
A. Varasteh Moradi ◽  
M. Ebadii ◽  
R. Zafar Mehrabian
Keyword(s):  
Molecularly Imprinted Polymer ◽  
Limit Of Detection ◽  
Diabetes Type 2 ◽  
Differential Pulse ◽  
Template Molecule ◽  
Imprinted Polymer ◽  
Limit Of Quantification ◽  
Molecularly Imprinted ◽  
Galega Officinalis ◽  
Relative Standard

Galega officinalis products have been used for the control of diabetes (type 2) across the world. Experimental and clinical evaluations of galegine substance produced by a medicinal plant (Galega officinalis) provided the pharmacological and chemical basis for metformin discovery which was confirmed for diabetes therapy. In this paper, the molecularly imprinted polymer (MIP) was synthesized for galegine, using galegine as a template molecule, methacrylic acid (MAA) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as a cross-linker, azobisisobutyronitrile (AIBN) as a reaction initiator, and acetonitrile as a solvent. The assisted functional groups, morphology, topographic image of surface, and crystalline structure of synthesized MIP were characterized by FT-IR spectroscopy, field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) images, and XRD diffraction pattern techniques, respectively. Also, the performance of the mentioned electrode was quantified and qualified by the differential pulse voltammetry technique (DPV). The galegine amount was determined with the polarographic technique. In this research, the galegine extraction conditions were optimized and graphene nanoparticles were used to increase the adsorption. In addition, different parameters affecting extraction were investigated such as MIP adsorbent amount, pH of solution, effect of the surfactant, and ionic compound to achieve high recovery percent. The recovery percent, limit of detection (LOD), limit of quantification (LOQ), and relative standard deviation (RSD %) were 4.101 μg·mL−1, 12.427 μg·mL−1, and 1.199% (n = 3), respectively. The results show that the prepared MIP can be used as an effective and inexpensive adsorbent for preconcentration and galegine extraction from a natural sample. It is noteworthy that this developed method was used successfully to determine galegine extracted from Galega officinalis L.

scholarly journals Redesigning an Electrochemical MIP Sensor for PFOS: Practicalities and Pitfalls

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4433 ◽  
Author(s):  
Giulia Moro ◽  
Davide Cristofori ◽  
Fabio Bottari ◽  
Elti Cattaruzza ◽  
Karolien De Wael ◽  
...  
Keyword(s):  
Molecularly Imprinted Polymer ◽  
Electrochemical Sensors ◽  
Differential Pulse ◽  
Complete Characterization ◽  
In Situ Monitoring ◽  
Template Molecule ◽  
Imprinted Polymer ◽  
Heterogeneous Distribution ◽  
Molecularly Imprinted ◽  
Mip Sensor

There is a growing interest in the technological transfer of highly performing electrochemical sensors within portable analytical devices for the in situ monitoring of environmental contaminants, such as perfluorooctanesulfonic acid (PFOS). In the redesign of biomimetic sensors, many parameters should be taken into account from the working conditions to the electrode surface roughness. A complete characterization of the surface modifiers can help to avoid time-consuming optimizations and better interpret the sensor responses. In the present study, a molecularly imprinted polymer electrochemical sensor (MIP) for PFOS optimized on gold disk electrodes was redesigned on commercial gold screen-printed electrodes. However, its performance investigated by differential pulse voltammetry was found to be poor. Before proceeding with further optimization, a morphological study of the bare and modified electrode surfaces was carried out by scanning electron microscopy–energy-dispersive X-ray spectrometry (SEM–EDS), atomic force microscopy (AFM) and profilometry revealing an heterogeneous distribution of the polymer strongly influenced by the electrode roughness. The high content of fluorine of the target-template molecule allowed to map the distribution of the molecularly imprinted polymer before the template removal and to define a characterization protocol. This case study shows the importance of a multi-analytical characterization approach and identify significant parameters to be considered in similar redesigning studies.

scholarly journals Laser-Induced Graphene Electrodes Modified with a Molecularly Imprinted Polymer for Detection of Tetracycline in Milk and Meat

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 269
Author(s):  
Biresaw D. Abera ◽  
Inmaculada Ortiz-Gómez ◽  
Bajramshahe Shkodra ◽  
Francisco J. Romero ◽  
Giuseppe Cantarella ◽  
...  
Keyword(s):  
Molecularly Imprinted Polymer ◽  
Limit Of Detection ◽  
Low Cost ◽  
Electrochemical Techniques ◽  
Differential Pulse ◽  
Animal Origin ◽  
Label Free ◽  
Imprinted Polymer ◽  
Meat Extract ◽  
Molecularly Imprinted

Tetracycline (TC) is a widely known antibiotic used worldwide to ‘’treat animals. Its residues in animal-origin foods cause adverse health effects to consumers. Low-cost and real-time measuring systems of TC in food samples are, therefore, extremely needed. In this work, a three-electrode sensitive and label-free sensor was developed to detect TC residues from milk and meat extract samples, using CO2 laser-induced graphene (LIG) electrodes modified with gold nanoparticles (AuNPs) and a molecularly imprinted polymer (MIP) used as a synthetic biorecognition element. LIG was patterned on a polyimide (PI) substrate, reaching a minimum sheet resistance (Rsh) of 17.27 ± 1.04 Ω/sq. The o-phenylenediamine (oPD) monomer and TC template were electropolymerized on the surface of the LIG working electrode to form the MIP. Surface morphology and electrochemical techniques were used to characterize the formation of LIG and to confirm each modification step. The sensitivity of the sensor was evaluated by differential pulse voltammetry (DPV), leading to a limit of detection (LOD) of 0.32 nM, 0.85 nM, and 0.80 nM in buffer, milk, and meat extract samples, respectively, with a working range of 5 nM to 500 nM and a linear response range between 10 nM to 300 nM. The sensor showed good LOD (0.32 nM), reproducibility, and stability, and it can be used as an alternative system to detect TC from animal-origin food products.

Construction and Studies of Histamine Potentiometric Sensors Based on Molecularly Imprinted Polymer

2020 ◽  
Vol 16 (6) ◽  
pp. 788-794 ◽  
Author(s):  
Atsuko Konishi ◽  
Shigehiko Takegami ◽  
Tatsuya Kitade
Keyword(s):  
Molecularly Imprinted Polymer ◽  
Limit Of Detection ◽  
Reference Electrode ◽  
Potentiometric Sensors ◽  
Template Molecule ◽  
Uv Spectrophotometry ◽  
Imprinted Polymer ◽  
Potential Response ◽  
Molecularly Imprinted ◽  
Cross Linker

Objective: Molecularly Imprinted Polymer (MIP)-modified potentiometric sensors for histamine (HIS) (as denoted as HIS sensor) have been developed. Methods: The MIPs comprise HIS, Methacrylic Acid (MAA) and ethylene glycol dimethacrylate as the template molecule, functional monomer and cross-linker, respectively. To examine the specificity of the MIP to HIS, the MIP particles were prepared with varying ratios of HIS: MAA and the HIS binding amount toward the MIP particles was determined by UV spectrophotometry. Furthermore, to quantitatively determine the ability of MIP (H2M20) to HIS, a HIS sensor was measured using Ag/AgCl as a reference electrode. Results: MIP particles having a HIS:MAA of 2 mmol:20 mmol (MIP (H2M20)) had the largest HIS binding amount among the MIP particles prepared. Additionally, MIP (H2M20) displayed a HIS binding amount approximately two times larger than the corresponding non-imprinted polymer (NIP) particles in the absence of template. The HIS sensor potential change increased as a function of HIS concentration and exhibited a near-Nernstian response of −25.7 mV decade−1 over the HIS concentration range of 1×10−5 to 1×10−4 mol L−1 with a limit of detection of 9.6×10−6 mol L−1. From the Nernstian response value, it was observed that the HIS sensor could detect the di-protonated HIS binding to the MIP. Conversely, when comparing at the same HIS concentration, the potential response value of the sensors fabricated using NIP particles were significantly smaller than the values of the corresponding HIS sensor. Conclusion: The MIP-modified potentiometric sensors can potentially be employed as an analytical method to quantitatively determine various analytes.

Liquid Chromatography Analysis of Clozapine in Rat Brain Tissue, Using its Molecularly Imprinted Polymer after Administration of Toxic Dose of Drug and Lipid Emulsion Therapy

2019 ◽  
Vol 15 (3) ◽  
pp. 251-257
Author(s):  
Bahareh Sadat Yousefsani ◽  
Seyed Ahmad Mohajeri ◽  
Mohammad Moshiri ◽  
Hossein Hosseinzadeh
Keyword(s):  
Rat Brain ◽  
Brain Tissue ◽  
Molecularly Imprinted Polymer ◽  
Lipid Emulsion ◽  
Limit Of Detection ◽  
Imprinted Polymer ◽  
Toxic Dose ◽  
Molecularly Imprinted ◽  
The Brain ◽  
Rat Brain Tissue

Background:Molecularly imprinted polymers (MIPs) are synthetic polymers that have a selective site for a given analyte, or a group of structurally related compounds, that make them ideal polymers to be used in separation processes.Objective:An optimized molecularly imprinted polymer was selected and applied for selective extraction and analysis of clozapine in rat brain tissue.Methods:A molecularly imprinted solid-phase extraction (MISPE) method was developed for preconcentration and cleanup of clozapine in rat brain samples before HPLC-UV analysis. The extraction and analytical process was calibrated in the range of 0.025-100 ppm. Clozapine recovery in this MISPE process was calculated between 99.40 and 102.96%. The limit of detection (LOD) and the limit of quantification (LOQ) of the assay were 0.003 and 0.025 ppm, respectively. Intra-day precision values for clozapine concentrations of 0.125 and 0.025 ppm were 5.30 and 3.55%, whereas inter-day precision values of these concentrations were 9.23 and 6.15%, respectively. In this study, the effect of lipid emulsion infusion in reducing the brain concentration of drug was also evaluated.Results:The data indicated that calibrated method was successfully applied for the analysis of clozapine in the real rat brain samples after administration of a toxic dose to animal. Finally, the efficacy of lipid emulsion therapy in reducing the brain tissue concentration of clozapine after toxic administration of drug was determined.Conclusion:The proposed MISPE method could be applied in the extraction and preconcentration before HPLC-UV analysis of clozapine in rat brain tissue.

scholarly journals A Molecularly Imprinted Polymer for Selective Extraction of Phenolic Acids from Human Urine

2021 ◽  
Vol 11 (4) ◽  
pp. 1577
Author(s):  
Marco Mora-Granados ◽  
David González-Gómez ◽  
Jin Su Jeong ◽  
Alejandrina Gallego-Picó
Keyword(s):  
Phenolic Acids ◽  
Molecularly Imprinted Polymer ◽  
Human Urine ◽  
Limit Of Detection ◽  
Ph Dependence ◽  
Selective Extraction ◽  
Screening Methods ◽  
Specific Method ◽  
Imprinted Polymer ◽  
Molecularly Imprinted

Studies for monitoring the bioavailability of dietary flavonoid compounds generate great interest. Among them, low-molecular-weight phenolic acids, secondary metabolites present in colonic catabolism and urinary excretion, have been proposed as biomarkers of polyphenol intake. Using 4-hydroxyphenylacetic acid as a template, a molecularly imprinted polymer (MIP) was synthesized for selective extraction of these hydroxylated metabolites from human urine samples and posterior analysis in an HPLC-DAD-MS system. Polymers were characterized by Scanning electron microscopy (SEM), Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), Brunauer-Emmett-Teller (BET) method, and binding experiments. MIP presents specific recognition ability for template and analogues molecules. This capacity of recognition and the pH dependence of the binding strength was also studied. The method was validated over a concentration range of 0.25–40 mg/L, r2 > 0.995. In the optimized conditions, the recovery value was 94% with RSD 1.2%. The Limit of Detection (LOD) and Limit of Quantification (LOQ) were 1.22 and 3.69 mg/L, respectively. In our knowledge, it is the first time that this methodology is applied to analyze urinary catabolites of the polyphenol compound and to provide a specific method and simple analysis alternative. The selective extraction of these metabolites improves the application and results obtained by other less sensitive analysis methods than the validation method. It also facilitates the development of new screening methods.

scholarly journals Removal of bisphenol A from aqueous media using a highly selective adsorbent of hybridization cyclodextrin with magnetic molecularly imprinted polymer

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
S. Mamman ◽  
F. B. M. Suah ◽  
M. Raaov ◽  
F. S. Mehamod ◽  
S. Asman ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Molecularly Imprinted Polymer ◽  
Binding Capacity ◽  
Bulk Polymerization ◽  
Resonance Spectroscopy ◽  
Template Molecule ◽  
Order Kinetic ◽  
Imprinted Polymer ◽  
Molecularly Imprinted ◽  
Magnetic Molecularly Imprinted Polymer

In this study, a unique magnetic molecularly imprinted polymer (MMIP) adsorbent towards bisphenol A (BPA) as a template molecule was developed by bulk polymerization using β-cyclodextrin (β-CD) as a co-monomer with methacrylic acid (MAA) to form MMIP MAA–βCD as a new adsorbent. β-CD was hybridized with MAA to obtain water-compactible imprinting sites for the effective removal of BPA from aqueous samples. Benzoyl peroxide and trimethylolpropane trimethacrylate were used as the initiator and cross-linker, respectively. The adsorbents were characterized by Fourier transform infrared spectroscopy, scanning electronic microscopy, transmission electron microscopy, vibrating sample magnetometer, Brunauer–Emmett–Teller and X-ray diffraction. 1 H nuclear magnetic resonance spectroscopy was used to characterize the MAA–βCD and BPA–MAA–βCD complex. Several parameters influencing the adsorption efficiency of BPA such as adsorbent dosage, pH of sample solution, contact time, initial concentrations and temperature as well as selectivity and reusability study have been evaluated. MMIP MAA–βCD showed significantly higher removal efficiency and selective binding capacity towards BPA compared to MMIP MAA owing to its unique morphology with the presence of β-CD. The kinetics data can be well described by the pseudo second-order kinetic and Freundlich isotherm and Halsey models best fitted the isotherm data. The thermodynamic studies indicated that the adsorption reaction was a spontaneous and exothermic process. Therefore, MMIP based on the hybrid monomer of MAA–βCD shows good potential of a new monomer in molecularly imprinted polymer preparation and can be used as an effective adsorbent for the removal of BPA from aqueous solutions.

Application of Response Surface Methodology to Synthesize Appropriate Molecularly Imprinted Polymer for Diazinon

2014 ◽  
Vol 605 ◽  
pp. 67-70 ◽  
Author(s):  
Mohsen Rahiminezhad ◽  
Seyed Jamaleddin Shahtaheri ◽  
Mohammad Reza Ganjali ◽  
Abbas Rahimi Rahimi Forushani
Keyword(s):  
Molecular Imprinting ◽  
Molecularly Imprinted Polymer ◽  
Binding Sites ◽  
Capillary Electrochromatography ◽  
Template Molecule ◽  
Imprinted Polymer ◽  
Molecularly Imprinted ◽  
Functional Monomers ◽  
Molecular Imprinting Technology ◽  
Cross Linker

Molecular imprinting technology has become an interesting research area to the preparation of specific sorbent material for environmental and occupational sample preparation techniques (1). In the molecular imprinting technology, specific binding sites have been formed in polymeric matrix, which often have an affinity and selectivity similar to antibody-antigen systems (2). In molecular imprinted technology, functional monomers are arranged in a complementary configuration around a template molecule, then, cross-linker and solvent are also added and the mixture is treated to give a porous material containing nono-sized binding sites. After extraction of the template molecule by washing, vacant imprinted sites will be left in polymer, which are available for rebinding of the template or its structural analogue (3). The stability, convention of preparation and low cost of these materials make them particularly attractive (4). These synthetic materials have been used for capillary electrochromatography (5), chromatography columns (6), sensors (7), and catalyze system (8). Depending on the molecular imprinting approach, different experimental variables such as the type and amounts of functional monomers, porogenic solvent, initiator, monomer to cross-linker ratio, temperature, and etc may alter the properties of the final polymeric materials. In this work, chemometric approach based on Central Composite Design (CCD) was used to design the experiments as well as to find the optimum conditions for preparing appropriate diazinon molecularly imprinted polymer.

scholarly journals Synthesis of Magnetic Molecularly Imprinted Polymer Sorbents for Isolation of Parabens from Breast Milk

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4328
Author(s):  
Martyna Pajewska-Szmyt ◽  
Ewelina Biniewska ◽  
Bogusław Buszewski ◽  
Renata Gadzała-Kopciuch
Keyword(s):  
Breast Milk ◽  
Limit Of Detection ◽  
Polymer Surface ◽  
Magnetic Core ◽  
Template Molecule ◽  
Limit Of Quantification ◽  
Rapid Separation ◽  
Molecularly Imprinted ◽  
Imprinted Polymers ◽  
Polymer Sorbents

Magnetic molecularly imprinted polymers (MMIPs) are an invaluable asset in the development of many methods in analytical chemistry, particularly sample preparation. Novel adsorbents based on MMIPs are characterized by high selectivity towards a specific analyte due to the presence of a specific cavity on their polymer surface, enabling the lock–key model interactions to occur. In addition, the magnetic core provides superparamagnetic properties that allow rapid separation of the sorbent from the sample solution. Such a combination of imprinted polymers with a magnetic core has an innovative influence on the development of separation techniques. Hence, the present study describes the synthesis of MMIPs with 17β-estradiol used as a template molecule in the production of imprinted polymers. The as-prepared sorbent was used for a sorption/desorption study of five parabens from breast milk samples. The obtained results were characterized by sorption efficiency exceeding 92%, which shows the high affinity of the analytes to the functional groups on the sorbent. The final determination of the selected analytes was done with high-performance liquid chromatography using a fluorometric detector. The determined linearity ranges for selected parabens were characterized by high determination coefficients (r2 from 0.9992 to 0.9999), and the calculated limit of detection (LOD) and limit of quantification (LOQ) for the identified compounds were low (LOD from 1.1–2.7 ng mL−1; LOQ from 3.6–8.1 ng mL−1), which makes their quantitative analysis in real samples feasible.

scholarly journals Detection of dopamine by a minimized electrochemical sensor using a graphene oxide molecularly imprinted polymer modified micropipette tip shaped graphite electrode

2021 ◽  
pp. 174751982198995
Author(s):  
Yi Wang ◽  
Jianshe Tang ◽  
Li Xiang
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Molecularly Imprinted Polymer ◽  
Carbon Paste Electrode ◽  
Limit Of Detection ◽  
Carbon Paste ◽  
Imprinted Polymer ◽  
Molecularly Imprinted ◽  
Paste Electrode

A simple and efficient electrochemical sensor based on a homemade reshaped micropipette tip carbon paste electrode is reported. Molecularly imprinted polymer membranes of graphene oxide and polypyrrole are synthesized and modified on the surface of micropipette tip carbon paste electrode. The merit of the method is evaluated under optimized conditions via differential pulse voltammetrics. The prepared sensor exhibits remarkable sensitivity toward dopamine with a linear range of 6.4 × 10−8–2 × 10−4 M, with a limit of detection as low as 1 × 10−8 M. The proposed method is applied for the determination of dopamine in urine samples by the standard addition route. A range of 1 × 10−7–1 × 10−4 M is obtained from these samples. The relative recoveries are in the range of 95.2%–104%. The proposed method has acceptable performance for the determination of dopamine in real samples with excellent sensitivity and selectivity.

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