Synthesis, characterization and magnetic property of maghemite (γ-Fe{sub 2}O{sub 3}) nanoparticles and their protective coating with pepsin for bio-functionalization

Journal Article · Thu Oct 15 00:00:00 EDT 2015 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2015.04.035· OSTI ID:22475897

Bandhu, A.; Sutradhar, S.; Mukherjee, S. ^[1]; Greneche, J. M. ^[2]

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1. Solid State Research Laboratory, Department of Physics, Burdwan University, Burdwan 713104, West Bengal (India)
2. Laboratoire de Physique de l’Etat Condensé – UMR CNRS 6087, Université du Maine, 72085, Le Mans Cedex 9 (France)

Highlights: • Maghemite nanoparticles were prepared by a modified co-precipitation method. • Nanoparticles were then successfully coated with pepsin for bio-functionlization. • XRD and Mössbauer spectra confirmed the maghemite phase of the nanoparticles. • Magnetic data were analysed to evaluate particle size, anisotropy etc. - Abstract: Maghemite nanoparticles (γ-Fe{sub 2}O{sub 3}) are prepared by co-precipitation method. To obtain bio-functionalized magnetic nanoparticles for magnetically controlled drug delivery, the prepared nanoparticles are successfully coated with pepsin, a bio-compatible polymer and digestive enzyme. Crystallographic phase of the nanoparticles is confirmed by X-ray diffractograms (XRD), high resolution transmission electron microscopy (HRTEM) and {sup 57}Fe Mössbauer spectrometry. The average size of nanoparticles/nanocrystallites is estimated from the (3 1 1) peak of the XRD pattern using Debye–Scherrer formula. Results of HRTEM of coated and bare samples are in good agreement with those extracted from the XRD analysis. The dynamic magnetic properties are observed and different quantities viz., coercive field, magnetization, remanence, hysteresis losses etc., are estimated, which confirmed the presence of superparamagnetic relaxation of nanoparticles. Mössbauer spectra of the samples recorded at both 300 and 77 K, confirmed that the majority of particles are maghemite together with a very small fraction of magnetite nanoparticles.

• OSTI ID: 22475897
• Journal Information: Materials Research Bulletin, Vol. 70; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
ANISOTROPY
COPRECIPITATION
CRYSTALLOGRAPHY
IRON 57
IRON OXIDES
IRON-GAMMA
MAGNETIC PROPERTIES
MAGNETITE
MAGNETIZATION
MOESSBAUER EFFECT
NANOPARTICLES
PARTICLE SIZE
PEPSIN
POLYMERS
RESOLUTION
SPECTROSCOPY
SUPERPARAMAGNETISM
SYNTHESIS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION