Magnetite nanoparticles coated with β-cyclodextrin functionalized-ionic liquid: Synthesis and its preliminary investigation as a new sensing material

doi:10.1016/j.apsusc.2015.09.078

Applied Surface Science

Volume 357, Part A, 1 December 2015, Pages 543-550

https://doi.org/10.1016/j.apsusc.2015.09.078 Get rights and content

Highlights

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A novel of β-cyclodextrin functionalized-ionic liquid coated with magnetite nanoparticles is prepared via co-precipitation method.
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The architecture of the material is successfully characterized and confirmed that β-cyclodextrin-functionalized-ionic liquid, has been effectively coated onto surface of Fe₃O₄ magnetite nanoparticles.
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Vibration Sample Magnetometer analysis confirmed that the Fe₃O₄-β-CD-IL able to attain an excellent magnetic properties.
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Preliminary electrochemical study shows that Fe₃O₄-β-CD-IL able to recognize Biphenol A.

Abstract

In this study, a novel surface of modified magnetite nanoparticles Fe₃O₄ was coated with β-cyclodextrin-funclionalized ionic liquid (Fe₃O₄-β-CD-IL) via the co-precipitation method in alkaline salt medium. β-Cyclodextrin-functionalized-ionic liquid has been effectively coated onto the surface of Fe₃O₄ magnetite nanoparticles. The instruments used to investigate the architecture are: Fourier Transform Infrared Spectroscopy, X-ray Powder Diffraction, Electron Microscope-Energy Dispersive X-Ray Spectrometry, Transmission Electron Microscope, Field Emission Scanning Electron Microscope, Vibrating Sample Magnetometer and Brunauer–Emmett–Teller isotherm. A Vibration Sample Magnetometer analysis verified that the Fe₃O₄-β-CD-IL attained excellent magnetic properties. The analysis of High Resolution Transmission Electron Microscope shows that the Fe₃O₄-β-CD-IL produced monodisperse particles with minimal aggregation. Moreover, electrochemical studies have revealed that this new material showed outstanding ability to recognize Bisphenol A with lower electrochemical potential at 0.5 V than other comparative materials, as well as a higher detection current. Thus, this material has promising potential as a new electrode material in sensor applications.

Introduction

Advances in nanoscale sciences have attracted much attention among researchers to uncover new prospective applications. Development in nanotechnology and nanoscience is mainly centered on producing particles uniform in nanometer size, shape and arrangement. With excellent properties as well as notable characteristics, magnetite nanoparticles (Fe₃O₄) have invoked a lot of interest and research efforts. Their large surface areas, quantum size effect and superparamagnetic behavior [1] offer a broad range of potential applications, including magnetic drug target [2], nano-sorbents in environmental engineering [3], magnetic resonance imaging [4], [5], [6], [7], biomedicine [8], biosensor [9] as well as catalysis and magnetic sensing [5]. Various preparation methods of magnetic nanoparticles have been reported, such as thermal decomposition, forced hydrolysis, electrochemical synthesis, sonochemical method and ultrasonic assisted impregnation [10], [11], [12], [13], [14], [15], [16]. One of the most distinguished methods to synthesize magnetite is by co-precipitation, which yields a success rate of 96–99.9% [13].

However, there are a few problems associated with magnetic nanoparticles preparation. The small size of the nanoparticles tends to agglomerate and reduce the surface area, which minimized the surface energy. In addition, magnetic nanoparticles without protection/shell can be easily oxidized, which will result in the loss of magnetism and dispensability [17]. Currently, the most frequently used method to promote the performance of the nanoparticles is the surface modification of magnetite nanoparticles. Recently, however, strategies have been introduced to graft β-CD onto the surface of magnetite nanoparticles [18], [19]. The first reported study on designing magnetite nanoparticles functionalized with β-CD for drug delivery is by Banerjee and Chen [20], while Badruddoza et al. [21] have demonstrated β-CD conjugated magnetite nanoparticles as a stripping agent in protein refolding. At the same time, Zhu et al. [22] have explored the potential of β-CD decorated magnetite nanoparticles as uric acid sensor. The introduction of β-CD onto the surface of magnetite produces interesting properties and enhances the stability of magnetite nanoparticles. Cyclodextrins (CDs) are cyclic oligosaccharides obtained from starch through enzymatic degradation [23]. There are three types of cyclodextrin comprising of six, seven and eight (d)-+-glucopyranose units, which are linked with α-1,4-glycosidic bonds and known as α, β, and γ-cyclodextrin, respectively [24]. CDs are widely known for their host-guest inclusion interactions [25]. Among the three types of cyclodextrin, β-CD has a rather rigid structure, complete with a secondary belt formed by hydrogen bonds [26]. Furthermore, β-CD shows excellent intermolecular interaction due to its hydrophobic cavity, which can accommodate and recognize various types of compounds.

Owing to the outstanding properties of β-CD, a novel approach is employed to synthesize magnetite nanoparticles coated with β-CD functionalized with 1-methylimidazole, which forms β-cyclodextrin-ionic liquid complexes (β-CD-IL). Ionic liquids (ILs) are a group of molten salts that result from the combination of organic cation and various anions [27]. They typically exhibit many distinctive properties as have been reported in many studies [28], [29], [30], [31]. ILs have been an area of interest for reasons associated with their negligible vapor pressure, high ionic mobility, excellent thermal and chemical stabilities as well as solvent capability. Researchers have only recently begun to see its use in the area of structural materials science. The immobilization of ionic liquids on a solid support makes it possible to take advantage of their unique properties in the solid state.

In this work, we aim to design and characterize a new magnetite nanoparticle holding simultaneously the unique properties β-CD and ILs. The choice of β-CD for this formulation is based on its combination of hydrophilic units ( single bond OH), which can bind onto iron oxide nanoparticles surfaces. Ionic liquids can influence the properties of β-CD and vice versa, indirectly affecting the overall properties of magnetite nanoparticles. Our study is the first attempt at decorating Fe₃O₄ nanoparticles using β-CD-ILs. The presence of ionic liquids has been attractive in the preparation of well-dispersed magnetite nanoparticles. Therefore, the nanostructure, morphology and magnetic properties of modified magnetite nanoparticles with β-CD-IL were studied in detail. Their formation and characterization were compared with pure Fe₃O₄ and Fe₃O₄ coated with native β-CD as references. The special interest in this work is the usage of Fe₃O₄-β-CD-IL as modified electrode for the detection of Bisphenol A (BPA). Although BPA is known as an electrochemically active compound, however, the direct determination using bare electrode is not applicable due to poor responses. Herein the result of Fe₃O₄-β-CD-IL as modified electrode shows a good electrochemical performance compared to unmodified magnetite nanoparticles and bare electrode. Consequently, the Fe₃O₄-β-CD-IL shows a good capability and opportunities for application in the field of sensor.

Section snippets

Materials and reagents

In this study, iron (II) chloride tetrahydrate (FeCl₂·4H₂O), iron (III) chloride tetrahydrate (FeCl₃·6H₂O, 99%), ammonium hydroxide (NH₄OH, 25%), and 1-methylimidazole were purchased from Sigma–Adrich while β-cyclodextrin (β-CD, 99%) was purchased from Across (Hungary). Pottasium Ferricyanide Fe(CN)₆^3−/4− was purchased from Merck and Bisphenol A (BPA) was purchased from Aldrich Chemical Co. (USA). Solvents such as dried Dimethyformamide (DMF) and hexane anhydrous were purchased from Merck. A

Structural characterization

FT-IR spectra of the synthesized Fe₃O₄ magnetite nanoparticles and modified Fe₃O₄ magnetite nanoparticles were carried out to identify the coating of β-CD and β-CD-IL on the surface of nanoparticles. Fig. 1(a)–(c) shows the peak associated with Fe–O presenting the tetrahedral side of pure magnetic nanoparticles at about 560–590 cm⁻¹ for Fe₃O₄, Fe₃O₄-β-CD and Fe₃O₄-β-CD-IL, respectively. The pure magnetite nanoparticles exhibited a broad absorption peak of around 3220 cm⁻¹, and was assigned to the

Conclusion

Magnetite nanoparticle Fe₃O₄ coated with β-CD and β-CD-IL was synthesized using the co-precipitation method. The nanoparticles were successfully characterized and the result showed that Fe₃O₄ nanoparticles had been effectively modified with supramolecule-ionic liquid. Supramolecule ionic liquids could influence the morphology and minimize the aggregation of magnetite nanoparticles. The unique combination of iron nanoparticles and modified β-cyclodextrin with ionic liquid plus the strong

Acknowledgements

The authors acknowledge, with thanks, the following: UMRG Project: RG188-12SUS, UMRG Program: RP006C-13SUS, and Postgraduate Research Grant: PG026-2013A from University of Malaya and The Ministry of Education Malaysia for MyBrain15 (My-PhD) scholarship.

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Magnetite nanoparticles coated with β-cyclodextrin functionalized-ionic liquid: Synthesis and its preliminary investigation as a new sensing material

Highlights

Abstract

Introduction

Section snippets

Materials and reagents

Structural characterization

Conclusion

Acknowledgements

Mater. Lett.

Waste Manag.

J. Coll. Interf. Sci.

J. Magn. Magn. Mater.

Electrochim. Acta

J. Magn. Magn. Mater.

Thin Solid Films

J. Magn. Magn. Mater.

Appl. Surf. Sci.

J. Hazard. Mater.

Appl. Surf. Sci.

Water Res.

Trac-Trends Anal. Chem.

Tetrahedron Lett.

Colloids Surf. A: Physicochem. Eng. Asp.

Appl. Surf. Sci.

A simple way to synthesize superparamagnetic iron oxide nanoparticles in air atmosphere: iron ion concentration effect

Magn. IEEE Trans.

A study on iron oxide nanoparticles coated with dextrin obtained by coprecipitation

Dig. J. Nanomater. Biostruct.

A green and facile approach for synthesis of magnetite nanoparticles

J. Nanosci. Nanotechnol.

Synthesis and spectral characterization of iron based micro and nanoparticles

Int J. Nanomater. Biostruct.

Osteoblast interaction with iron oxide nanoparticles coated with dextrin in cell culture

J. Optoelectron. Adv. Mater.

Properties of Fe3O4 nanoparticles by co-precipitation method to removal procion dye

Int. J. Environ. Sustain. Dev.

Properties of Fe₃O₄ nanoparticles by co-precipitation method to removal procion dye