Browsing by Author "R.K. Vatsa"

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Bi-functional properties of Fe3O4@YPO4:Eu hybrid nanoparticles: Hyperthermia application
(2013) A.I. Prasad; A.K. Parchur; R.R. Juluri; N. Jadhav; B.N. Pandey; R.S. Ningthoujam; R.K. Vatsa
Magnetic nanoparticles based hyperthermia therapy is a possible low cost and effective technique for killing cancer tissues in the human body. Fe 3O4 and Fe3O4@YPO4:5Eu hybrid magnetic nanoparticles are prepared by co-precipitation method and their average particle sizes are found to be ∼10 and 25 nm, respectively. The particles are spherical, non-agglomerated and highly dispersible in water. The crystallinity of as-prepared YPO4:5Eu sample is more than Fe 3O4@YPO4:5Eu hybrid magnetic nanoparticles. The chemical bonds interaction between Fe3O4 and YPO 4:5Eu is confirmed through Fe⋯O-P. The magnetization of hybrid nanocomposite shows magnetization Ms = 11.1 emu g-1 with zero coercivity (measured at 2 × 10-4 Oe) at room temperature indicating superparamagnetic behaviour. They attain hyperthermia temperature (∼42°C) under AC magnetic field showing characteristic induction heating of the prepared nanohybrid and they will be potential material for biological application. Samples produce the red emission peaks at 618 nm and 695 nm, which are in range of biological window. The quantum yield of YPO4:5Eu sample is found to be 12%. Eu3+ present on surface and core could be distinguished from luminescence decay study. Very high specific absorption rate up to 100 W g-1 could be achieved. The intracellular uptake of nanocomposites is found in mouse fibrosarcoma (Wehi 164) tumor cells by Prussian blue staining. © 2013 The Royal Society of Chemistry.
Effect of EDTA on luminescence property of Eu+3 doped YPO 4 nanoparticles
(2010) A.K. Parchur; G.S. Okram; R.A. Singh; R. Tewari; Lina Pradhan; R.K. Vatsa; R.S. Ningthoujam
Nanoparticles of Eu3+ doped YPO4 have been prepared using ethylene glycol (EG). Ethylene diamine tetra acetic acid (EDTA) is used as a complexing agent. X-ray diffraction results show that the nanoparticles are crystalline in tetragonal structure. Based on William-Hall relation, the effective crystallite size and strain developed in lattice are found to be 28 nm and 0.002, respectively. With the addition of EDTA, there is a slight shift towards the lower wavelength in emission peaks. Asymmetric ratio of electric to magnetic dipole transition intensities are found to decrease with addition of EDTA. Emission intensity decreases with EDTA because of decrease of particle size as well as decrease of number of Eu3+ activators per unit volume. These materials are dispersible in water, which may have potential biological applications. © 2010 American Institute of Physics.