Sensors & Transducers 2015 by IFSA Publishing, S. L.

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1 Sensors & Transducers 15 by IFSA Publishing, S. L. Mössbauer, VSM and X-ray Diffraction Study of Fe 3 O (NP s)/pvoh for Biosensors Applications 1 Almuatasim Alomari, Hasan M. El Ghanem, 3 Abdel-Fatah Lehlooh, Isam M. Arafa, 5 Ibrahim Bsoul, 1 Ashok Batra 1 Department of Physics, Chemistry and Mathematics (Materials Science Group) College of Engineering, Technology, and Physical Sciences Alabama A&M University Normal, Alabama 3576 USA Department of Physics, Jordan University of Science & Technology, Irbid, 11, Jordan 3 Physics Department, Yarmouk University, Irbid 11-63, Jordan Department of Chemistry, Jordan University of Science & Technology, Irbid, 11, Jordan 5 Physics Department, Al al-bayt University, Mafraq 13, Jordan 1 Tel.: (56)37-819, fax: (56) ashobatra@gmail.com Received: 8 August 15 /Accepted: 1 September 15 /Published: 3 September 15 Abstract: In this article, structure and magnetic properties of nano magnetic Fe 3 O (magnetite) nanoparticles functionalized polyvinyl alcoholic (PVOH) have been investigated by X-ray diffraction (XRD), Vibrating sample magnetometer (VSM) and Mossbauer Spectroscopy (MS) for use in biosensor applications. XRD showed an average of cluster sizes using Debye Scherrer formula are between 1-13 nm. The magnetization data at room temperature shows weak hysteresis loops and the isotherms of the magnetization curves indicate that superparamagnetism superimposed on the paramagnetic behavior exists in all coated samples. The paramagnetic contribution in coated samples was found to perfectly fit a Langevin equation, with an average number of magnetic dipole moments around Bohr magnetons. The results of MS showed that all magnetic components corresponding to iron oxide particles in polymer spectrum split into a number of sextet separated by about 1-35 T. The line width, relative intensity and the values of the hyperfine fields and isomer shifts for the magnetic components of the samples are estimated. It was found that only the Fe 3 O sample is suitable for practical medical applications such as, drug delivery systems and to design artificial muscles due to its sufficiently high value of saturation magnetization and attraction to magnet ability. Copyright 15 IFSA Publishing, S. L. Keywords: Nano magnetic Fe 3 O nanoparticles, X-ray diffraction, Debye Scherrer formula, Vibrating sample magnetometer, Mossbauer Spectroscopy, Langevin equation. 1. Introduction Synthesis of superparamagnetic iron oxide nanoparticles (SPION) with polymers has gained increasing interest for emerging applications as tissue repair, drug delivery and in cell separation, cellular imaging in magnetic resonance imaging (MRI), sensors, imaging agents, storage media and catalysis 53

2 in biotechnology and biomedical application [1-7]. One of the most important features is to prepare coated particles with iron oxide core shell for use in applications that require high magnetization values at room temperature, nontoxic fine particles and have long time stability with size smaller than 1 nm [8]. Many researchers have studied structure and magnetic properties of iron oxide as metal alloy and produced new spinel iron oxide hybrids [9-11], they have also studied it as amorphous with a short-range crystallinity, where amorphous nature of the atomic arrangements has been observed [1]. Uniformly dispersed amorphous nanoparticles of magnetite in a polyvinyl alcohol matrix have been obtained by ultrasound radiation [13]. In other research composite was prepared by mechanical milling of Fe 3 O / SiO material constitutes a mixture of ultrafine Fe-rich spinel particles (magnetite/maghemite) [1]. The preparation of magnetite (Fe 3 O ) has been typically performed by particle precipitation from the hydrolysis and condensation of iron (II)/iron (III) salts in basic media stable aqueous dispersions of magnetic iron oxide colloids were initially generated by ball milling of large particles in the presence of organic stabilizers [15-18]. Solution methods were also developed to prepare aqueous Fe 3 O sols, it was reported that the particle size of Fe 3 O colloids approximate of 1 nm [19-]. Dextran coated iron oxide nanoparticles were synthesized by addition of FeCl and FeCl 3 in the presence of ammonium hydroxide (NH OH) and the polysaccharide surfactant (M n =, g/mol), SEM showed the size of Iron oxide nanoparticles is between 1 nm [1]. Polymer coated magnetite nanoparticles were synthesized by in situ precipitation in the presence of poly (vinyl alcohol) (PVOH) (M n =, g/mol) from an aqueous mixture of ferric and ferrous chloride salts in an alkaline media []. It was reported that the prepared samples showed superparamagnetic Fe 3 O colloid behavior with nanoparticles size is in the range of 1 nm using XRD, VSM, and TEM. A comparative study of dextran versus the PVOH surfactants in the precipitation of iron oxide colloids was also conducted [3]. A recent report showed the preparation of PVOH coated Fe 3 O colloids using sonochemical methods from iron (II) acetate precursors yielding superparamagnetic hybrid materials []. PVOH magnetite ferrogels prepared using freezing and thawing cycles showed superparamagnetic properties that can be tailored for drug delivery systems and to design artificial muscles [5]. One of the important material which can be immobilized on magnetic nanoparticles in order to use them for biosensing purposes is Streptavidin [6]. Streptavidin is known for its special affinity towards the vitamin biotin and hence it is suitable for detection of diverse biomolecules in immunoassays, e.g. detection of viral nucleic acids in vitro [7]. This paper is aimed at the study of basic magnetic properties of iron oxide Fe 3 O coated with PVOH and non-coated iron oxide Fe 3 O prepared by low-cost conventional sonication method to determined functionality for use in biosensing and biomedical applications.. Experimental Section Polyvinyl alcohol (PVOH,7g/mol) was suspended in 1 ml of 1, ethylenedichloride (C H Cl ) in a closed container and subjected to sonication for about 1 h at 6-7 o C. To this solution palmatoyl chloride (C 15 H 31 COCl, xxxx g/mol) was added with continuous sonication. The reaction mixture proceeded rapidly after addition of triethylamine base (NEt 3 ) with the elimination of triethylammonium chloride salt. The obtained reaction mixture was left overnight in the closed container. This afford.15 g of different amounts of palmatoyl chloride is added to afford.15 g of the required modified matrix (palmatoyl-pvoh) with different degree of substitution, see Table 1. Table 1. Relative samples contents of PVOH, C15H31COCl (g) and Number of palmatoyl substituted vinyloh units in poly (palm-g- PVOH) polymer backbone. Sample PVOH (g) C15H31COCl (g) Number of palmatoyl substituted vinyloh units on palmatoyl PVOH polymer backbone S : S : S :6 S :8 S :1 S :1 To each of the above rapidly stirred solutions 1 ml of aqueous solution containing 1: molar ratio of FeCl :H O (1.19 g) and FeCl 3 :6H O (3.3 g) was added. The resulting colloidal mixture was sonicated for 3- minutes to ensure homogeneous distribution of Fe + and Fe 3+ in the colloidal solution of the matrix system. The chloride salt of iron was then converted into oxide by adding 5-6 ml ammonia while the solution is under sonication. Immediately the colloidal solution becomes dark indicating the formation of magnetic particles. Sonication continued for ~ 1 h and left for few hours before suction filtration. The obtained materials were vacuum dried at 7 o C. This procedure gives 1.39 g of Fe 3 O tiny particles entrapped into the spaces provided by.15 g of the palmatoyl-modified PVOH matrix. In other words, the percent of magnetite in each matrix is 5.1 %. Approximate particle size of samples was determined using X-ray diffraction and Debye Scherrer formula. The vibrating sample magnetometer has become a widely used instrument 5

3 for determining magnetic properties of a large variety of materials: diamagnetic, paramagnetic, ferromagnetic and antiferromagnetic. In this case we used VSM MicroMag 39, Princeton Measurements Corporation. The value of magnetic field was between to 1 Tesla at different temperatures. The source of γ ray in Mössbauer device was a 5 mci of Co 57. The computer processing of the spectra showed intensities I of the components (atomic fraction of Fe atoms), hyperfine inductions B hf, isomer shifts δ, and quadrupole splitting QS. field on the material (Oe), kt: is the thermal energy (ev), χ: is the susceptibility. The reduced magnetization M * (H, T) can be obtained by [3]: M * (H, T) =M (H, T) - χ p H, (5) where M is the total measured magnetization, a is a fitting parameter and χ p is the high field paramagnetic susceptibility. 3. Mathematical Section 3.1. X-ray Diffraction (XRD) X-ray diffraction (XRD) is a versatile, nondestructive technique that reveals detailed information about the chemical composition and crystallographic structure of natural and manufactured materials. The Debye Scherrer formula can be used to determine the size of particles of crystals in the form of powder. The Debye Scherrer formula can be written as [8]: Kλ D =, (1) β cosθ. Results and Discussion Fig. 1 shows the X-ray diffraction patterns of uncoated and coated Fe 3 O magnetite NP s synthesized by sonication method. All peaks of the uncoated Fe 3 O particles matches exactly the prepared peaks of six coated samples. The calculations of uncoated and coated Fe 3 O particles made on the peak centered at 1 o, using Equation (1). The average diameter of the particles assuming spherical Fe 3 O clusters is of the order of 13 nm (nano-sized particles). where D is the mean size of the ordered domains, K is a dimensionless shape factor, λ is the X-ray wavelength (1.556 Å), β is the line broadening at half the maximum intensity (FWHM). 3.. Langevin Function The Langevin function can be written as [9]: M M s 1 = coth( a), () a Intensity (a. u.) S1 S S3 S S5 S6 Fe 3 O where M is the total magnetization (emu/g), M s is the saturation magnetization (emu/g), a is the ratio of the Zeeman energy of the magnetic moment in the external field to the thermal energy. The Langevin theory also leads to the Curie law. For small a [9]: Therefore: nμ H M = (3) 3kT nμ χ =, () 3kT where n is the number of atoms per unit volume, µ is the magnetic moment (emu), H is the acted magnetic θ Fig. 1. X-ray diffraction patterns of all samples with Fe3O. The magnetization (M) versus the applied magnetic field (H) was carried out at room temperature as shown in Fig.. The results showed weak hysteresis loop for all six uncoated samples at room temperature. The corriesive field (H c ) was too low to be measured, while the remnance magnetization (M r ) varies for samples as shown in Fig. 3 (a) for sample (S3), while Fe 3 O showed high value of magnetization compared to other samples as shown in Fig. 3 (b). 55

4 Magnetization (emu/g) S1 S S3 S S5 S6 shown in Fig. 5. The susceptibility, the saturation magnetization M s and the average magnetic dipole moment for all samples are calculated and tabulated in Table H (koe) Fig.. Magnetic hysteresis curves of all coated samples. M (emu/g) T= 98 o K T= 33 o K T= 373 o K T= 3 o K T= 73 o K H c = Oe Mr=. (emu/g) Magnetization (emu/g) H (Oe) H (koe) (a) - H c =51 Oe Mr=5. (emu/g) Magnetization (emu/g) (a) H (Oe) - M (emu/g) H (koe) (b) T= 98 o K T= 33 o K T= 373 o K T= 3 o K T= 73 o K -6 (b) Fig. 3. Magnetic hysteresis curves of (a) sample 3 (S3), and (b) Fe3O. The isothermal magnetization curves of different samples have been determined at temperatures between 98 to 73 K o. The isothermal curves of samples show a large initial slope and nearly linear behavior for large fields; this suggests that the system contains paramagnetic and apparently superparamagnetic contribution, as shown in Fig.. A very good agreement between the reduced magnetization and the Langevin function found as Fig.. Selected isothermal total magnetization measurements for (a) sample 3 (S3), and (b) sample Fe3O at different selected temperature from 98 to 73 (K o ). Table. The susceptibilities, the saturation magnetization Ms and the average magnetic dipole moment µ. Sample χo χp Ms μ (emu/g) (emu/g) S S S S S S Fe3O

5 M (emu/g) 1 M (Measured) M* Langevin H (koe) Fig. 5. Magnetization curve of the sample 3 (S3). The best least square fit with Equation (). The Mössbauer spectra show magnetic ordering with broad magnetic splitting, and superparamagnetic behavior. Hence, the spectra are fitted with (one or more) magnetic sextets and one quadrupole. The fitted Mössbauer spectra are shown in Fig. 6. The Mössbauer parameters are listed in Table 3. Table 3. Hyperfine field Beff, Quadruple Splitting (QS), and Isomer Shift (δ) Results of Mössbauer Spectra for all samples. Sample S1 S S3 S S5 S6 Fe3O Sub spectra Beff (T) QS (mm/s) δ (mm/s) The spectrum for Sample 1 (S1) is fitted by one broad magnetic sextet with a hyperfine field (B hf =1 T) and one quadrupole with quadrupole splitting (QS=.7 mm/s) and relative intensity I %=8 %. The spectrum for Sample (S) is fitted with three magnetic sextets with an average hyperfine field (B hf =35.9 T) and one quadrupole with quadrupole splitting (QS=.71 mm/s) and relative intensity I %=8 %. The spectrum for Sample 3 (S3) is fitted with three magnetic sextets with an average hyperfine field (B hf =39.9 T) and one quadrupole with quadrupole splitting (QS=.69 mm/s) and relative intensity I %=65 %. The spectrum for Sample (S) is fitted with three magnetic sextets with an average hyperfine field (B hf =37.9 T) and one quadrupole with quadrupole splitting (QS=.7 mm/s) and relative intensity I %=58 %. The spectrum for Sample 5 (S5) is fitted with two magnetic sextets with an average hyperfine field (B hf =39.7 T) and one quadrupole with quadrupole splitting (QS=.73 mm/s) and relative intensity I %=7 %. The spectrum for Sample 6 (S6) is fitted with two magnetic sextets with an average hyperfine field (B hf =39. T) and one quadrupole with quadrupole splitting (QS=.73 mm/s) and relative intensity I %=63 %. The spectrum for sample Fe 3 O is fitted by five magnetic sextets with an average hyperfine field (B hf =3 T) without quadrupole splitting. The magnetic ordered phases represented by magnetic sextets correspond to iron atoms in an iron oxide phases (magnetite) with large particle sizes, large enough to have net magnetic moment manifested by magnetic Zeeman splitting but not large enough to have well define magnetic splitting as in bulk magnetite. The quadrupole in the spectra which is found to be around (QS.7 mm/s) could be attributed to iron oxide phase (most probable magnetite as the XRD data shows) with small particle sizes, small enough that the particles behave superparamagnetic (zero net magnetic moment). The relative intensity of the quadrupole is found to be greater than that of the magnetic sextet in the spectra of nearly all the samples. This indicates that the iron oxide phases produced are below the blocking volumes at room temperature or blocking temperatures below room temperature (fine particle sizes), hence, behaving superparamagnetically. In brief; all samples show as indicative of superparamagnetic particles of magnetite and slight hyperfine splitting. The MS parameters are similar to all samples indicating that the iron oxide particles have the same environment for all samples. The slight difference of hyperfine spectrum in samples suggests that small sized particles are produced (fine nanoparticles) when iron oxides nanoparticles were synthesized in presence of PVOH-palmitoyl chloride matrix [3]. 57

6 S1 S S3 Relative Transmission (a.u.) S S5 S6 Relative Transmission (a.u.) Fe 3 O Relative Transmission (a.u.) Fig. 6. Mössbauer spectra of samples: S1, S, S3, S, S5, S6 and Fe3O sample. 5. Conclusions In this research, we report the preparation of iron oxide (Fe 3 O ) coated with PVOH polymer in different number of palmatoyl chloride relative to hydroxyl group on the backbone. The XRD data used to determine the average size of the Fe 3 O clusters is found to be around 1-13 nm. The magnetization measurement on all samples is carried out at different temperature, revealing that all samples contain superparamagnetic contribution. The paramagnetic saturation magnetization was calculated using Langevin function and found to be between -9 emu/g for coated samples and 6 emu/g for Fe 3 O sample. The average magnetic dipole moment was calculated to be around Bohr magnetons. 58

7 The Mössbauer data indicate that the samples have superparamagnetic behavior and fine particles. The isomer shift, the relative intensities and quadruple splitting appear to be independent on the number of palmatoyl chloride relative to number of hydroxyl group, and this was confirmed by the value of the slight hyperfine splitting. In short, only the Fe 3 O sample is suitable for practical medical applications such as, drug delivery systems and biosensing purposes due to its sufficiently high value of saturation magnetization and attraction to magnet ability. References [1]. A. K. Gupta, S. Wells, Surface modified superparamagnetic nanoparticles for drug delivery: preparation, characterization and cytotoxicity studies, IEEE Transaction on Nanobioscience, Vol. 3, Issue 1,, pp []. A. K. Gupta, M. Gupta, Cytotoxicity suppression and cellular uptake enhancement of surface modified magnetic nanoparticles, Biomaterials, Vol. 6, Issue 13, 5, pp [3]. H. Gu, K. Xu, C. Xu, B. Xu, Biofunctional magnetic nanoparticles for protein separation and pathogen detection, Chemical Communications, Vol. 9, Issue 9, 5, pp []. F. Shamsipour, et al., Conjugation of Monoclonal Antibodies to Super Paramagnetic Iron Oxide Nanoparticles for Detection of her/neu Antigen on Breast Cancer Cell Lines, Avicenna J. Med Biotechnol, Vol. 1, Issue 1, 9, pp [5]. D. K. Kim, et al., Superparamagnetic iron oxide nanoparticles for bio-medical application, Scripta Materialia, Vol., Issue 8-9, 1, pp [6]. Andrea Fornara, et al., Tailored magnetic nanoparticles for direct and sensitive detection of biomolecules in biological samples, Nano Letters, Vol. 8, Issue 1, 8, pp [7]. J. Lodhia, G. Mandarano, N. J. Ferris, S. F. Cowell, Development and use of iron oxide nanoparticles (Part 1): Synthesis of iron oxide nanoparticles for MRI, Biomedical Imaging and Intervention Journal, Vol. 6, No., 1, pp [8]. Y. Zhang, N. Kohler, M. Zhang, Surface modification of superparamagnetic magnetite nanoparticles and their intracellular uptake, Biomaterials, Vol. 3, No. 7,, pp [9]. R. Y. Hong, et al., On the Fe3O/Mn1-xZnxFeO core/shell magnetic nanoparticles, Journal of Alloys and Compounds, Vol. 8, Issue, 9, pp [1]. A. P. Douvalis, et al., Revealing the interparticle magnetic interactions of iron oxide nanoparticlescarbon nanotubes hybrid materials, in Proceedings of the International Conference on the Applications of the Mössbauer Effect (ICAME 9), Vienna, Austria, 19- July 9, pp. 1-. [11]. G. A. Al-Nawashi, S. H. Mahmood, A. D. Lehlooh, A. S. Saleh, Mössbauer spectroscopic study of orderdisorder phenomena in Fe3-xMnxSi, Physica B: Condensed Matter, Vol. 31, Issues 1-,, pp [1]. S. M. Yusuf, et al., Structural and magnetic properties of amorphous iron oxide, Physica B: Condensed Matter, Vol. 5, Issue, 1, pp [13]. C. Yee, et al., Self-Assembled Monolayers of Alkanesulfonic and -phosphonic Acids on Amorphous Iron Oxide Nanoparticles, Langmuir, Vol. 15, No. 1, 1999, pp [1]. J. H. Yu, C. W. Lee, S. S Im, J. S. Lee, Structure and magnetic properties of SiO coated FeO3 nanoparticles synthesized by chemical vapor condensation process, Reviews on Advanced Materials Science, Vol., Issue 1, 3, pp [15]. P. S. Stephen, Low viscosity magnetic fluid obtained by the colloidal suspension of magnetic particles, U.S. Patent , November [16]. R. E. Rosensweig, J. W. Nestor, R. S. Timmins, Ferrohydrodynamic fluids for direct conversion of heat energy, in Mater. Assoc. Direct Energy Convers. Proc. Symp. AIChE-I. Chem. Eng. Ser. 5, 1965, pp [17]. R. Kaiser, G. Miskolczy, Magnetic properties of stable dispersion of subdomain magnetite particles, Journal of Applied Physics, Vol. 1, No. 3, 197, pp [18]. A. E. Berkowitz, J. A. Lahut, C. E. Van Buren, Properties of magnetic fluid particles, IEEE Transaction on Magnetics, Vol. 16, Issue, 198, pp [19]. W. C. Elmore, Ferromagnetic colloid for studying magnetic structures, Physical Review Letters, Vol. 5, Issue, 1938, pp []. R. Massart, Preparation of aqueous magnetic liquids in alkaline and acidic media, IEEE Transaction on Magnetics, Vol. 17, Issue, 1981, pp [1]. R. S. Molday, D. Mackenzie, Immunospecific ferromagnetic iron-dextran reagents for the labeling and magnetic separation of cells, Journal of Immunological Methods, Vol. 5, Issue 3, 198, pp []. J. Lee, T. Isobe, M. Senna, Preparation of ultrafine Fe3O particles by precipitation in the presence of PVA at high ph, Journal of Colloid and Interface Science, Vol. 177, Issue, 1996, pp [3]. H. Pardoe, W. Chua-Anusorn, T. G. St. Pierre, J. Dobson, Structural and magnetic properties of nanoscale iron oxide synthesized in the presence of dextran, or polyvinylalcohol, Journal of Magnetism and Magnetic Materials, Vol. 5, Issue 1-, 1, pp []. R. Abu-Much, U. Meridor, A. Frydman, A. Gedanken, Formation of a three-dimensional microstructure of Fe3O-poly (vinyl alcohol) composite by evaporating the hydrosol under a magnetic field, Journal of Physical Chemistry B, Vol. 11, Issue 16, 6, pp [5]. P. J. Reséndiz-Hernández, O. S. Rodríguez- Fernández, L. A. Garcia-Cerda, Synthesis of poly (vinyl alcohol) magnetite ferrogel obtained by freezing thawing technique, Journal of Magnetism and Magnetic Materials, Vol. 3, Issue 1, 8, pp. e373-e376. [6]. H. L. Liu, C. H. Sonn, J. H. Wu, K. M. Lee, Y. K. Kim, Synthesis of streptavidin-fitc-conjugated core-shell Fe3O-Au nanocrystals and their application for the purification of CD(+) lymphocytes, Biomaterials, Vol. 9, Issue 9, 8, pp [7]. J. Drbohlavova, et al., Preparation and Properties of Various Magnetic Nanoparticles, Sensors, Vol. 9, Issue, 9, pp

8 [8]. B. D. Cullity, S. R. Stock, Elements of X-Ray Diffraction, 3 rd ed., Prentice-Hall Inc., Upper Saddle River, NJ, 1. [9]. B. D. Cullity, C. D. Graham, Introduction to Magnetic Materials, nd ed., Addison-Wesley Publishing Company, 9. [3]. P. V. Finotelli, D. A. Sampaio, M. A. Morales, A. M. Rossi, M. H. Rocha-Leão, Ca Alginate As Scaffold For Iron Oxide Nanoparticles Synthesis, Brazilian Journal of Chemical Engineering, Vol. 5, No., 8 pp Copyright, International Frequency Sensor Association (IFSA) Publishing, S. L. All rights reserved. ( 6