Magnetic Molecularly Imprinted Polymer Nanoparticles Research Articles

Sensitive detection of synthetic cannabinoids in human blood using magnetic polydopamine molecularly imprinted polymer nanocomposites.

Synthetic cannabinoids (SCs) are a series of artificial chemical substances with pharmacological properties similar to those of natural cannabinoids and their abuse poses a great risk to social security and human health. However, the highly sensitive detection of low concentrations of SCs in human serum remains a great challenge. In this work, we developed a highly sensitive, rapid and highly selective method for the detection of SCs in human serum. Magnetic molecularly imprinted polymer (MIP) nanocomposites were prepared through self-polymerization of dopamine and template molecules on the surfaces of magnetic beads. 9H-Carbazole-9-hexanol (9CH) was used as a template molecule because of its long chain structure shared with six synthetic cannabinoids and its ability to provide specific recognition sites. With these magnetic MIP nanoparticles, six SCs could be rapidly and effectively extracted from human blood. The concentrations of six SCs could be accurately determined by high-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis. The limits of detection were in the range of 0.1-0.3 ng mL-1. The proposed method is characterized by high sensitivity and selectivity, and has great potential for application in the analysis of practical samples.

Protein Denaturation Through the Use of Magnetic Molecularly Imprinted Polymer Nanoparticles.

The inhibition of the protein function for therapeutic applications remains challenging despite progress these past years. While the targeting application of molecularly imprinted polymer are in their infancy, no use was ever made of their magnetic hyperthermia properties to damage proteins when they are coupled to magnetic nanoparticles. Therefore, we have developed a facile and effective method to synthesize magnetic molecularly imprinted polymer nanoparticles using the green fluorescent protein (GFP) as the template, a bulk imprinting of proteins combined with a grafting approach onto maghemite nanoparticles. The hybrid material exhibits very high adsorption capacities and very strong affinity constants towards GFP. We show that the heat generated locally upon alternative magnetic field is responsible of the decrease of fluorescence intensity.

Preparation of Magnetic Molecularly Imprinted Polymer (MMIP) Nanoparticles (NPs) for the Selective Extraction of Tetracycline from Milk

Core-shell magnetic molecularly imprinted polymer nanoparticles (MMIP NPs) were prepared for the adsorption and the isolation of tetracycline from food matrices. The obtained MMIP NPs were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffractometry, vibrating sample magnetometry, and thermogravimetric analysis. The adsorption properties of the MMIP NPs were systematically characterized by static, kinetic, and selective adsorption as well as reusability measurements. The MMIP NPs were shown to provide a high adsorption capacity, with a maximum value of 40.48 mg/g, satisfactory selectivity with an imprinting factor equal to 2.55, and direct magnetic separation. Moreover, the MMIP NPs were successfully applied to extract tetracycline from milk samples. Satisfactory recoveries from 91.14 to 104.52% were obtained.

Magnetic molecularly imprinted polymer nanoparticles for dispersive micro solid-phase extraction and determination of buprenorphine in human urine samples by HPLC-FL

A simple, sensitive and accessible while reliable method was developed and validated for quantitation of buprenorphine (Bup) as a highly lipophilic drug in human urine samples. The proposed method is based on a rapid and easy dispersive micro solid-phase extraction procedure using magnetic molecularly imprinted polymer nanoparticles (MMIPNPs), magnetite (Fe3O4) cores surrounded by polyamidoamine and Bup as template, followed by high-performance liquid chromatographic analysis with fluorescence detector (HPLC-FL). The prepared MMIPNP adsorbent was characterized by different techniques. Transmission electron microscopy images show that the Fe3O4 core nanoparticles are well enwrapped by MIP layers. In determination process, Bup could be quantitatively extracted using MMIPNPs and then can be easily desorbed by mixture of sodium hydroxide (0.1 mol/L) and methanol (1:9, v/v) solution before injection to HPLC. The relative recoveries of Bup were found to be 97.4–100.3%, and the linear dynamic range was within the ranges of 1–1000 ng/mL with R2 of 0.9998. Remarkably high quality of 0.21 and 0.71 ng/mL was obtained as the limit of detection and limit of quantification, respectively. The developed method was successfully applied for determination of Bup in infected human urine samples.

Preparation of a magnetic molecularly imprinted polymer for the selective adsorption of chlordiazepoxide and its determination by central composite design optimized HPLC

Core–shell magnetic molecularly imprinted polymer nanoparticles (MMIP-NPs) were prepared and applied in the extraction of chlordiazepoxide from various samples.

Magnetic molecularly imprinted polymer nanoparticles-based solid-phase extraction coupled with gas chromatography-mass spectrometry for selective determination of trace di-(2-ethylhexyl) phthalate in water samples.

Novel magnetic molecularly imprinted polymer nanoparticles (MMIPs) were synthesized by surface imprinting technology with a sol-gel process, using di(2-ethylhexyl)phthalate (DEHP) as the template. The MMIPs were characterized using Fourier transform-infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). The MMIPs displayed good adsorption selectivity for DEHP, with selectivity coefficients of 5.2 and 4.8 with respect to di-n-octyl phthalate and dibutyl phthalate, respectively. The reusability of MMIPs was demonstrated for at least eight repeated cycles without significant loss in adsorption capacity. A novel method for selective preconcentration and determination of trace DEHP in aqueous solutions was developed by using the magnetic DEHP-imprinted nanoparticles as adsorbent for solid-phase extraction (SPE) coupled with gas chromatography-mass spectrometry (GC-MS). The optimum SPE conditions were as follows: adsorbent amount, 50mg; sample volume, 100mL; adsorption time, 20min; eluent, chloroform; and desorption time, 5min. Results showed that the limit of detection (LOD) and limit of quantification (LOQ) for DEHP were 0.02 and 0.075μgL-1, respectively. The proposed method was applied to the determination of DEHP in different real water samples, with spiked recovery of 93.3-103.2% and RSD of 1.2-3.2%. Therefore, the developed analytical method is rapid, sensitive, and accurate, which provides a new option for the detection of trace DEHP in aqueous samples.

Synthesis and characterization of magnetic molecularly imprinted polymer nanoparticles for controlled release of letrozole

Synthesis and characterization of magnetic letrozole imprinted polymer nanoparticles is described herein for the first time. Magnetic molecularly imprinted polymers (MMIPs) were synthesized by precipitation polymerization using methacrylic acid (MAA) as functional monomer and trimethylolpropane trimethacrylate (TRIM) as crosslinker in the presence of letrozole as template and MAA-modified magnetite nanoparticles as magnetic component. The nanoparticles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and a vibrating sample magnetometer (VSM). The synthesized MMIP nanoparticles, with particle size of about 100 nm, showed superparamagnetic features with a saturation magnetization of 12.5 emu·g−1 and had thermal stability below 240 °C. The adsorption experiments indicated better template recognition of MMIP than magnetic non-imprinted polymer (MNIP) nanoparticles. Moreover, the release profile of letrozole from MMIP and MNIP revealed the controlled release ability of MMIP nanoparticles for the letrozole anticancer drug. We also found that applying an external alternative magnetic field results in increasing the rate of the drug release.

Synthesis and characterization of core–shell magnetic molecularly imprinted polymer nanoparticles for selective extraction of tizanidine in human plasma

In this study, simple, effective and general processes were used for the synthesis of a new nano-molecularly imprinted polymers (MIPs) layer on magnetic Fe3O4 nanoparticles (NPs) with uniform core–shell structure by combining surface imprinting and nanotechniques. The first step for the synthesis of magnetic NPs was co-precipitation of Fe2+ and Fe3+ in an ammonia solution. Then, an SiO2 shell was coated on the magnetic core with the Stöber method. Subsequently, the C=C groups were grafted onto the silica-modified Fe3O4 surface by 3-(trimethoxysilyl) propyl methacrylate. Finally, MIPs films were formed on the surface of Fe3O4@SiO2 by the copolymerization of C=C end groups with methacrylic acid (functional monomer), ethylene glycol dimethacrylate (cross-linker), 2,2-azobisisobutyronitrile (initiator) and tizanidine (template molecule). The products were characterized using techniques that included Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermo gravimetric analysis (TGA), scanning electron microscopy (SEM), UV spectrophotometry, transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). Measurement of tizanidine through use of the core–shell magnetic molecularly imprinted polymers nanoparticles (MMIPs-NPs) in human plasma samples compared to the paracetamol showed that the synthesized nanosized MMIP for tizanidine has acted selectively.

Preparation of Magnetic Molecularly Imprinted Polymer Nanoparticles for Selective Adsorption and Separation of β-Estradiol

In this study, we report the synthesis of MIP-coated hybrid NPs by “semi-covalent” imprinting technique throught a thermally reversible covalent bond and application for biochemical separation of β-estradiol (E2). A moleculary imprinted polymer (MIP) were synthesized using 3-(triethoxysilyl) propyl isocyanate and dibutyltin dilanurate as a functional monomer and cross-linking agent and β-estradiol as template. The removal of the template by a simple thermal reaction produced specific β-estradiol recognition sites on the surface of silica shell. Meanwhile, a solid-phase extraction (SPE) based on E2- MMIPs has been established for efficient separation and fast enrichment of E2 from the plasma. Recoveries of E2 from two kinds of plasma spiked at different concentration levels ranged from 86.9 to 103.3 with RSD <1.76 %.In this manner LOD was 0.0019 and LOQ was 0.0057 (µmol L−1), capacity factor and selectivity factor were 3.05 and 1.099 respectively. Also E2- MMIPs was used for selective separation of E2 from drugs mixture.

Magnetic molecularly imprinted polymer nanoparticles for selective solid phase extraction and pre-concentration of Tizanidine in human urine.

In this work, the magnetic molecularly imprinted polymer nanoparticles (MMIP-NPs) for the selective pre-concentration of Tizanidine have been described. The polymer nanoparticles were synthesized by the polymerization of methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, 2,2-azobisisobutyronitrile as an initiator and Tizanidine as a template molecule. The MMIP-NPs were characterized by scanning electron microscopy (SEM) and thermogravimeteric analysis (TGA). Imprinted Tizanidine molecules were removed from the polymeric structure using acetic acid in methanol (10:90 V/V%), as the eluent solvent. The limits of detection (L.O.D) for Tizanidine were 1.13×10(-6)M and 1.68×10(-6)M in ultrapure water and urine, respectively. Also, the relative standard deviations (R.S.D) in ultrapure water and urine were 2.21% and 2.58%, respectively. The method was applied to the determination of Tizanidine in the human urine samples.

Magnetic molecularly imprinted polymer nanoparticles for selective extraction of copper from aqueous solutions prior to its flame atomic absorption determination

This paper describes a pre-concentration procedure using magnetic molecularly imprinted polymer (MMIP) nanoparticles for the extraction of copper(II) from aqueous samples prior to its atomic absorption determination. Cu–morin complex was used as template molecule which was chemically bonded to MMIP nanoparticles. MMIP nanoparticles were characterized by scanning electron microscopy as well as Fourier transform infrared spectroscopy. The extraction conditions including pH value, adsorption and desorption time, temperature, amount of ligand and ionic strength of the sample matrix were studied and optimized. The method showed good extraction recoveries (≥96%) with relative standard deviation below 3.4% for real samples. The linear range of calibration curve was between 5–1000 μg/L with a correlation coefficient (r 2) of 0.996. The detection limit was 0.5 μg/L. The method was suitable for the determination of trace copper in drinking water samples.

Construction a magneto carbon paste electrode using synthesized molecularly imprinted magnetic nanospheres for selective and sensitive determination of mefenamic acid in some real samples

A novel magneto multiwalled carbon nanotube/carbon paste electrode (MMW/CPE) for the determination of mefenamic acid (MFA) was introduced. Magnetic molecularly imprinted polymer nanoparticles (MMIPNPs) were synthesized and then added to the solution of MFA. After stirring for 20min, the MMW/CPE was immersed in the solution of MFA (contain MMIPNPs) and the MMIPNPs were captured by it. Then oxidation of MFA was analyzed by differential pulse voltammetry (DPV). Electrochemical impedance spectroscopy, cyclic voltammetry, and DPV were employed to characterize the MMW/CPE. The MMIPNPs exhibited a high selectivity and sensitivity toward MFA. The effect of various experimental parameters including pH, MMIPNPs dosage, stirring time, accumulation potential and time on the voltammetric response of MFA were investigated. Under the optimal conditions, selective detection of MFA in a linear concentration range of 2.0–1000.0nmolL−1 was performed with the detection limit of 1.2nmolL−1 (3S/N). To further study the practical applicability of this method, it was applied to the analysis of some real samples and the obtained results were satisfactory.

Magnetic Molecularly Imprinted Polymer Nanoparticles for Selective Extraction of Copper from Aqueous Solutions Prior to Its Flame Atomic Absorption Determination

Magnetic Molecularly Imprinted Polymer Nanoparticles for Selective Extraction of Copper from Aqueous Solutions Prior to Its Flame Atomic Absorption Determination

Synthesis and Characterization of the Magnetic Molecularly Imprinted Polymer Nanoparticles Using N, N-bis Methacryloyl Ethylenediamine as a New Cross-linking Agent for Controlled Release of Meloxicam

The novel magnetic molecularly imprinted polymers (MMIPs) had been synthesized using N,N-bis methacryloyl ethylenediamine as a cross-linker for the controlled release of meloxicam at a pH of 1.0 (simulated gastric fluid), at a pH of 6.8 (simulated intestinal fluid) and at a pH of 7.4 (simulated biological fluids). The MMIPs were prepared via precipitation polymerization, using Fe3O4 as a magnetic component, meloxicam as a template molecule, methacrylic acid (MAA) as a functional monomer and N,N-bis methacryloyl ethylenediamine as a new cross-linker in acetonitrile/dimethyl sulfoxide porogen. Magnetic non-molecularly imprinted polymers (MNIPs) were also prepared with the same synthesis procedure as with MMIPs only without the presence of the template. The obtained MMIPs were characterized using transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR), dynamic light scattering (DLS), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and vibrating sample magnetometer (VSM). The performance of the MMIPs for the controlled release of meloxicam was assessed, and the results indicated that the magnetic MIPs also had potential applications in drug controlled release.

Preparation of Core‐shell Magnetic Molecularly Imprinted Polymer Nanoparticles for Recognition of Bovine Hemoglobin

Imprinting nanoparticles: Core-shell bovine hemoglobin (BHb) imprinted magnetic nanoparticles (MNPs) with a mean diameter of 210 nm have been synthesized for the first time. The imprinted magnetic nanoparticles could easily reach the adsorption equilibrium and magnetic separation under an external magnetic field, thus avoiding problems related to the bulk polymer. In this work, the core-shell bovine hemoglobin (BHb) imprinted magnetic nanoparticles (MNPs) with a mean diameter of 210 nm were synthesized for the first time. In this protocol, the initial step involved co-precipitation of Fe(2+) and Fe(3+) in an ammonia solution. Silica was then coated on the Fe(3)O(4) nanoparticles using a sol-gel method to obtain silica shell magnetic nanoparticles. Subsequently, 3-aminophenylboronic acid (APBA), which is the functional and cross-linking monomer, and poly(APBA) thin films were coated onto the silica-modified Fe(3)O(4) surface through oxidation with ammonium persulfate in an aqueous solution in the presence or absence of protein. The morphology, adsorption, and recognition properties of the magnetic molecularly imprinted nanomaterial were investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM). Rebinding experiments were carried out to establish the equilibrium time and to determine the specific binding capacity and selective recognition. The protein adsorption results showed that poly(APBA) MIPs-coated magnetic nanoparticles have high adsorption capacity for template protein BHb and comparatively low non-specific adsorption. The imprinted magnetic nanoparticles could easily reach the adsorption equilibrium and magnetic separation under an external magnetic field, thus avoiding problems related to the bulk polymer. We believe that the imprinted polymer-coated magnetic nanoparticles can be one of the most promising candidates for various applications, which include chemical and biochemical separation, cell sorting, recognition elements in biosensors, and drug delivery.