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

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.
Authors:
; ;  [1] ;  [2] ;  [1]
  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)
Publication Date:
OSTI Identifier:
22475897
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 70; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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