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 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 Molecularly imprinted polymer-based electrochemical sensors for biopolymers

2019 ◽  
Vol 14 ◽  
pp. 53-59 ◽  
Author(s):  
Frieder W. Scheller ◽  
Xiaorong Zhang ◽  
Aysu Yarman ◽  
Ulla Wollenberger ◽  
Róbert E. Gyurcsányi
Keyword(s):  
Molecularly Imprinted Polymer ◽  
Electrochemical Sensors ◽  
Imprinted Polymer ◽  
Molecularly Imprinted

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 A “Single-Use” Ceramic-Based Electrochemical Sensor Chip Using Molecularly Imprinted Carbon Paste Electrode

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5847
Author(s):  
Aaryashree ◽  
Yuuto Takeda ◽  
Momoe Kanai ◽  
Akihiko Hatano ◽  
Yasuo Yoshimi ◽  
...  
Keyword(s):  
Differential Pulse ◽  
Sensor Chip ◽  
Therapeutic Drug ◽  
Carbon Paste ◽  
Imprinted Polymer ◽  
Molecularly Imprinted ◽  
Single Use ◽  
Mip Sensor ◽  
Response Current ◽  
Time Required

An inexpensive disposable electrochemical drug sensor for the detection of drugs (vancomycin, meropenem, theophylline, and phenobarbital) is described. Molecularly imprinted polymer (MIP) templated with the target drugs was immobilized on the surface of graphite particles using a simple radical polymerization method and packed into the working electrode of a three-electrode ceramic-based chip sensor. Differential pulse voltammetry (DPV) was used to determine the relationship between the response current and the concentration of the targeted drug while using one sensor chip for one single operation. The time required for each DPV measurement was less than 2 min. Concentrations corresponding to the therapeutic range of these drugs in plasma were taken into account while performing DPV. In all the cases, the single-used MIP sensor showed higher sensitivity and linearity than non-imprinted polymer. The selectivity test in drugs with a structure similar to that of the target drugs was performed, and it was found that MIP-based sensors were more selective than the untreated ones. Additionally, the test in whole blood showed that the presence of interfering species had an insignificant effect on the diagnostic responses of the sensor. These results demonstrate that the disposable MIP-sensor is promising for quick and straightforward therapeutic drug monitoring to prevent the toxic side effects and the insufficient therapeutic effect due to the overdose and underdose, respectively.

scholarly journals Potentiometric PVC-Membrane-Based Sensor for Dimethylamine Assessment Using A Molecularly Imprinted Polymer as A Sensory Recognition Element

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1695
Author(s):  
Saad S. M. Hassan ◽  
Abd El-Galil E. Amr ◽  
Heba Abd El-Naby ◽  
Mohamed A. Al-Omar ◽  
Ayman H. Kamel ◽  
...  
Keyword(s):  
Detection Limit ◽  
Molecularly Imprinted Polymer ◽  
Sampling Rate ◽  
Pvc Membrane ◽  
Template Molecule ◽  
Imprinted Polymer ◽  
High Concentration ◽  
Buffer Solution ◽  
Molecularly Imprinted ◽  
Recognition Element

A new simple potentiometric sensor is developed and presented for sensitive and selective monitoring of dimethylamine (DMA). The sensor incorporates a molecularly imprinted polymer, with a pre-defined specific cavity suitable to accommodate DMA. The molecularly imprinted polymer (MIP) particles were dispersed in an aplasticized poly(vinyl chloride) matrix. The MIP is synthesized by using a template molecule (DMA), a functional monomer (acrylamide, AM), cross-linker (ethylene glycol dimethacrylate, EGDMA) and initiating reagent (benzoylperoxide, BPO). Using Trizma buffer solution (5 mmol L−1, pH 7.1), the sensor exhibits a rapid, stable and linear response for 1.0 × 10−5 to 1.0 × 10−2 mol L−1 DMA+ with a calibration slope of 51.3 ± 0.3 mV decade−1, and a detection limit of 4.6 × 10−6 mol L−1 (0.37 µg mL−1). The electrode exhibited a short response time (10 s) and stable potential readings (± 0.5 mV) for more than 2 months. Potentiometric selectivity measurements of the sensor reveal negligible interferences from most common aliphatic and aromatic amines. High concentration levels (100-fold excess) of many inorganic cations do not interfere. The sensor is successfully used for quantification of low levels of DMA down to 0.5 µg mL–1. Verification of the presented method was carried out after measuring the detection limit, working linearity range, ruggedness of the method, accuracy, precision, repeatability and reproducibility. Under flow-through conditions, the proposed sensor in its tubular form is prepared and introduced in a two-channel flow injection setup for hydrodynamic determination of DMA. The sampling rate is 50–55 samples h–1. The sensor is used to determine DMA in different soil samples with an accuracy range of 97.0–102.8%.

scholarly journals Electrochemical Sensor Based on Molecularly Imprinted Polymer for the Detection of Cefalexin

Biosensors ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 31 ◽  
Author(s):  
Bogdan Feier ◽  
Adrian Blidar ◽  
Alexandra Pusta ◽  
Paula Carciuc ◽  
Cecilia Cristea
Keyword(s):  
Electrochemical Sensor ◽  
Molecularly Imprinted Polymer ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Imprinted Polymer ◽  
Boron Doped Diamond ◽  
Molecularly Imprinted ◽  
Diamond Electrode ◽  
The Difference ◽  
Mip Sensor

In this study, a new electrochemical sensor was developed for the detection of cefalexin (CFX), based on the use of a molecularly imprinted polymer (MIP) obtained by electro‒polymerization in an aqueous medium of indole-3-acetic acid (I3AA) on a glassy carbon electrode (GCE) and on boron-doped diamond electrode (BDDE). The two different electrodes were used in order to assess how their structural differences and the difference in the potential applied during electrogeneration of the MIP translate to the performances of the MIP sensor. The quantification of CFX was performed by using the electrochemical signal of a redox probe before and after the rebinding of the template. The modified electrode was characterized using atomic force microscopy (AFM), scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The influence of different parameters on the fabrication of the sensor was tested, and the optimized method presented high selectivity and sensitivity. The MIP-based electrode presented a linear response for CFX concentration range of 10 to 1000 nM, and a limit of detection of 3.2 nM and 4.9 nM was obtained for the BDDE and the GCE, respectively. The activity of the sensor was successfully tested in the presence of some other cephalosporins and of other pharmaceutical compounds. The developed method was successfully applied to the detection of cefalexin from real environmental and pharmaceutical samples.

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