Polypyrrole-coated Magnetic Nanoparticles Research Articles

Rapid Determination of Vitamin D3 in Aquatic Products by Polypyrrole-Coated Magnetic Nanoparticles Extraction Coupled with High-Performance Liquid Chromatography Detection.

A method using polypyrrole-coated Fe3O4 (Fe3O4@PPy composites) based extraction coupled with high performance liquid chromatography was developed for adsorption and detection of trace vitamin D3 (VD3) in aquatic products. The fabricated Fe3O4@PPy composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Fe3O4@PPy composites showed efficient adsorption of VD3 at pH 9.0 and 25 °C with a dose of 25 mg per 10 mL of sample solution and an adsorption time of 11 min. Methanol was selected as the desorption solvent to recover VD3 from Fe3O4@PPy composites after 3 min of static treatment. Fe3O4@PPy composites can be used for VD3 adsorption at least two times. The developed method showed a good linearity for VD3 determination in the range of 0.1–10 μg/mL with a correlation coefficient of 0.9989. The limits of detection and quantification were 10 ng/mL and 33 ng/mL, respectively. The recovery of VD3 in a spiking test was 97.72% with a relative standard deviation value of 1.78%. The content of VD3 in nine aquatic products was determined with this method. Our results show that Fe3O4@PPy composites provide a convenient method for the adsorption and determination of VD3 from the complex matrix of aquatic products.

Magnetic solid-phase extraction of four β-lactams using polypyrrole-coated magnetic nanoparticles from water samples by micellar electrokinetic capillary chromatography analysis

In the present research, the application of a polypyrrole coating on Fe3O4 magnetic nanoparticles (PPy/Fe3O4 MNPs) as a sorbent was confirmed. The synthesized magnetic composites were characterized by TEM, FTIR spectroscopy, and XRD. Four β-lactams (oxacillin (OXA), cloxacillin (CLOX), dicloxacillin (DIC), and flucloxacillin (FLU)) were selected as analytes for the experiment. The extracted β-lactams were determined by micellar electrokinetic capillary chromatography-diode array detector (MEKC-DAD). The crucial parameters influencing the extraction efficiency and separation were studied and optimized. Under the optimal conditions, the limits of detection are 1.0 µg L−1 for OXA, CLOX, FLU, and 0.8 µg L−1 for DIC. The calibration curves are linear in the range of 2.5–200.0 µg L−1. The proposed method was applied for the determination of the β-lactams in water samples with satisfactory results. The intra-day relative standard deviations and the inter-day relative standard deviations range from 1.09% to 4.58% and from 2.95% to 7.80%, respectively. It can be concluded that this method is sensitive, convenient, and feasible for the determination of the β-lactams in water samples.

β-Cyclodextrin grafted polypyrrole magnetic nanocomposites toward the targeted delivery and controlled release of doxorubicin

The Fe3O4@PPy-HA-β-CD nanocomposites as the novel nanocarrier were prepared by grafting ethylenediamine derivative of​ β-​CD to the surface of polypyrrole-coated magnetic nanoparticles (Fe3O4@PPy) via using hyaluronan (HA) as the intermediate linker. HA was also the efficient target ligand for CD44. The as-prepared drug carrier was characterized by TEM, TGA, XRD, and VSM and used for the delivery of doxorubicin hydrochloride (DOX) with the high loading content of 447mg/g. The multilayer Freundlich isotherm model was found to be a good fit for the loading of the drug carrier for DOX. Significant NIR-triggered release of DOX was observed in a weak acidic pH. And the release data in vitro was well described using the Retiger-Pepper kinetic model. Furthermore, MTT assay and confocal microscopy against Hep-G2 cells clearly illustrated that the drug carrier had no associated cytotoxicity and could easily enter the cells. The release and accumulation of DOX were observed in the cell nuclei. Thus, the DOX-loaded drug carrier killed the cancer cells efficaciously and minimized adverse side effects due to its target effect. These results suggested the as-prepared drug carrier would be of great potential for the controlled release and targeted delivery of DOX.

Biosorption-based dispersive liquid-liquid microextraction combined with polypyrrole-coated magnetic nanoparticles as an effective sorbent for the extraction of ibuprofen from water samples using magnetic solid-phase extraction.

In this paper, biosorption-based dispersive liquid-liquid microextraction (BioDLLME) in combination with magnetic solid-phase extraction (MSPE) has been developed as a sample pretreatment method with high enrichment factor for the sensitive determination of ibuprofen in water samples. At first, magnetic Fe3 O4 /polypyrrole nanoparticles were synthesized and employed as sorbent for the MSPE of ibuprofen. After the elution of the desired compound from the sorbent by using methanol, BioDLLME technique was performed on the obtained solution. After MSPE, the eluent of MSPE was used as the disperser solvent for BioDLLME, so that the extra preconcentration factor could be achieved. The properties of the prepared magnetic sorbent were characterized using field emission scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction methods. Experimental parameters affecting the extraction efficiency were studied and optimized. Under optimum conditions, the enrichment factor was 274. The linear dynamic range and limit of detection are 0.25-80 and 0.083μg/L, respectively. The relative standard deviations for six replicate measurements are 3.82%.

Extraction and preconcentration of formaldehyde in water by polypyrrole-coated magnetic nanoparticles and determination by high-performance liquid chromatography.

In this study, a simple and rapid extraction method based on the application of polypyrrole-coated Fe3 O4 nanoparticles as a magnetic solid-phase extraction sorbent was successfully developed for the extraction and preconcentration of trace amounts of formaldehyde after derivatization with 2,4-dinitrophenylhydrazine. The analyses were performed by high-performance liquid chromatography followed by UV detection. Several variables affecting the extraction efficiency of the formaldehyde, i.e., sample pH, amount of sorbent, salt concentration, extraction time and desorption conditions were investigated and optimized. The best working conditions were as follows: sample pH, 5; amount of sorbent, 40 mg; NaCl concentration, 20% w/v; sample volume, 20 mL; extraction time, 12 min; and 100 μL of methanol for desorption of the formaldehyde within 3 min. Under the optimal conditions, the performance of the proposed method was studied in terms of linear dynamic range (10-500 μg/L), correlation coefficient (R(2) ≥ 0.998), precision (RSD% ≤ 5.5) and limit of detection (4 μg/L). Finally, the developed method was successfully applied for extraction and determination of formaldehyde in tap, rain and tomato water samples, and satisfactory results were obtained.

Polypyrrole-coated magnetic nanoparticles as an efficient adsorbent for RB19 synthetic textile dye: Removal and kinetic study

The present work deals with the first attempt to study the removal of synthetic textile dye, reactive blue 19 (RB19), using the magnetic Fe3O4 nanoparticles modified by pyrrole (PPy@Fe3O4 MNPs) as an efficient adsorbent. The nanoadsorbent was synthesized using chemical co-precipitation. Scanning electron microscopy and FT-IR were used to characterize nanoparticles. Factors affecting the dye adsorption including the pH of the dye solution, amount of adsorbent and contact time were also further investigated. Sorption of the RB19 on PPy@Fe3O4 MNPs reached to equilibrium at contact time less than 10min and fitted well to the Langmuir adsorption model with a maximum adsorption capacity of 112.36mgg−1. Experiments for adsorption kinetic were carried out and the data fitted well according to a pseudo-second-order kinetic model. Moreover, the MNPs were recovered with over than 90% efficiency using methanol as elution agent.

Adsorptive removal of alizarin red-S and alizarin yellow GG from aqueous solutions using polypyrrole-coated magnetic nanoparticles

The potential of polypyrrole-coated Fe3O4 nanoparticles (Fe3O4@PPy NPs) for removal of two anionic dyes from aqueous solutions was studied. The dye removal process was affected by several parameters such as pH, sorbent amount, and contact time, and were optimized using the response surface methodology (RSM) based on orthogonal central composite design (OCCD). The maximum removal of dyes was achieved at the adsorbent amount of 0.1–0.12g/100mL at pH 4–5.4 in 60min. Three kinetic models; namely, pseudo-first-order, pseudo-second-order, and intra-particle diffusion were used to analyze the adsorption mechanism. The kinetic results showed that the pseudo-second-order equation was the best model. The isotherm analysis indicated that the equilibrium data were well fitted to the Langmuir isotherm model, showing a monolayer adsorption manner of the dyes onto a homogeneous surface of the modified nanoparticles. According to the experimental results, about 97.8% of alizarin yellow and 78.7% of alizarin red were removed from aqueous solutions under optimal conditions. The maximum adsorption capacities for alizarin red-S and alizarin yellow GG in the concentration ranges studied were 116.3 and 113.6mgg−1, respectively, which were higher than the recent reports for potential adsorbents in the literature. The results obtained showed that the Fe3O4@PPy NPs are an appropriate adsorbent for removal of anionic dyes from aqueous solutions.

Extraction of three nitrophenols using polypyrrole-coated magnetic nanoparticles based on anion exchange process

In this research, the applicability of polypyrrole-coated Fe3O4 nanoparticles (Fe3O4@PPy NPs) as an anion exchange magnetic nanosorbent is demonstrated. For this purpose, three nitrophenols were selected as models which are acidic compounds with low logP values and their extraction in neutral form (only based on hydrophobic interactions) is difficult. The extracted nitrophenols were separated and determined by high-performance liquid chromatography-UV detection. The size, morphology and surface coating of synthesized Fe3O4@PPy NPs have been characterized via different techniques such as Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy and thermo-gravimetric analysis. The important parameters influencing the extraction efficiency were studied and optimized. Under the optimum extraction conditions (300mL sample solution with pH 10, extraction and desorption times of 10 and 2min, respectively, 500μL of 0.1M HNO3 in acetonitrile as eluent, and 40mg of adsorbent), a linear range between 0.75 and 100μgL−1 (R2>0.997), and limits of detection ranging from 0.3 to 0.4μgL−1 were obtained. Preconcentration factors in the range of 125–180 were achieved and relative standard deviations (RSDs%) were less than 4.9 (n=4) for the three nitrophenols. The analytical method was successfully applied for environmental water samples such as tap water, rain water and river water. The recoveries varied within the range of 84–109% confirming good performance of the method in various waters samples. The results showed that the proposed method is a rapid, convenient and feasible technique for determination of nitrophenols in aqueous samples.

Rapid CE-UV evaluation of polypyrrole-coated magnetic nanoparticles for selective binding of endocrine disrupting compounds and pharmaceuticals by aromatic interactions

Endocrine disrupting compounds (EDCs) and pharmaceuticals in water have negative impacts on human health and environmental ecology. Sorbents that can selectively remove these compounds based on their chemical functionality would have a significant health benefit to humans and wildlife. In this work, polypyrrole-coated magnetic nanoparticles (MNPs@PPy) were evaluated as a sorbent for extraction and preconcentration of bisphenol A (BPA), metformin (MF), naphthalene acetic acid (NAA), phenformin (PF) and triclosan (TC). Both in-capillary and in vitro binding efficiencies were determined using capillary electrophoresis with ultraviolet detection (CE-UV). In-capillary binding efficiencies of 99 ± 1% were found for BPA, PF and TC, which were confirmed by in vitro binding tests. Apparently, MNPs@PPy bound strongly with aromatic compounds due to π–π bonding interactions. A mixture of ethyl acetate and methanol (75 : 25 v/v) was evaluated as the eluting solvent. CE-UV analysis determined the % recoveries to be 85 ± 13% for MF and PF which were adequate for analyte preconcentration by this method. A new coating of PPy was successfully added on the used particles for regeneration of their surfaces to achieve a binding efficiency of as high as 94 ± 3%.