Effect of DNA coating on magnetic relaxation in γFc2O 3 nanoparticles

P. Dutta; M. S. Seehra

doi:10.1109/TMAG.2007.894001

Effect of DNA coating on magnetic relaxation in γFc₂O ₃ nanoparticles

P. Dutta, M. S. Seehra

Research output: Contribution to journal › Article › peer-review

5 Scopus citations

Abstract

In this paper, we compare the magnetic relaxation of DNA-coated γFe₂O₃ with that of parent 7-nm γFe ₂O₃ particles by measuring the temperature dependence of AC susceptibilities (χ′ and χ″) at frequency f = 0.1, 1, 10, 100, and 1000 Hz and electron magnetic resonance (EMR) at 9.28 GHz. Changes in the blocking temperature T_B (where χ′ peaks) with frequency are analyzed using the relation: T_B = T₀ + [T _a/ln(f₀/f)1 derived from Vogel-Fulcher relaxation, where T_a(T₀) measures the effective energy barrier (interparticle interaction). The fit to the data yields f₀ = 1.3 × 10¹⁶ Hz, T_a = 2760 K(2960 K), and T₀ = 40 K(20 K) for the uncoated (DNA-coated) γFe₂O₃. From the relative shift ΔT_m of T_m (the temperature where χ″ peaks) with change Δ log f in frequency, the parameterΦ = ΔT_m/(T_m Δ log f) is determined to be 0.04(0.06) for the uncoated (coated) γFe ₂O₃. These results show only minimal changes in the magnetic dynamics of γFe₂O₃ upon DNA coating.

Original language	English (US)
Pages (from-to)	2468-2470
Number of pages	3
Journal	IEEE Transactions on Magnetics
Volume	43
Issue number	6
DOIs	https://doi.org/10.1109/TMAG.2007.894001
State	Published - Jun 2007
Externally published	Yes

Keywords

Biocompatibility
Electron magnetic resonance
Magnetic nanoparticles
Magnetic relaxation

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Electrical and Electronic Engineering

Access to Document

10.1109/TMAG.2007.894001

Cite this

@article{d236fa64b5c8451f8d08cd1cc60104c1,

title = "Effect of DNA coating on magnetic relaxation in γFc2O 3 nanoparticles",

abstract = "In this paper, we compare the magnetic relaxation of DNA-coated γFe2O3 with that of parent 7-nm γFe 2O3 particles by measuring the temperature dependence of AC susceptibilities (χ′ and χ″) at frequency f = 0.1, 1, 10, 100, and 1000 Hz and electron magnetic resonance (EMR) at 9.28 GHz. Changes in the blocking temperature TB (where χ′ peaks) with frequency are analyzed using the relation: TB = T0 + [T a/ln(f0/f)1 derived from Vogel-Fulcher relaxation, where Ta(T0) measures the effective energy barrier (interparticle interaction). The fit to the data yields f0 = 1.3 × 1016 Hz, Ta = 2760 K(2960 K), and T0 = 40 K(20 K) for the uncoated (DNA-coated) γFe2O3. From the relative shift ΔTm of Tm (the temperature where χ″ peaks) with change Δ log f in frequency, the parameterΦ = ΔTm/(Tm Δ log f) is determined to be 0.04(0.06) for the uncoated (coated) γFe 2O3. These results show only minimal changes in the magnetic dynamics of γFe2O3 upon DNA coating.",

keywords = "Biocompatibility, Electron magnetic resonance, Magnetic nanoparticles, Magnetic relaxation",

author = "P. Dutta and Seehra, {M. S.}",

note = "Funding Information: ACKNOWLEDGMENT This work was supported in part by the U.S. Department of Energy under Grant DE-FC26-05NT42456.",

year = "2007",

month = jun,

doi = "10.1109/TMAG.2007.894001",

language = "English (US)",

volume = "43",

pages = "2468--2470",

journal = "IEEE Transactions on Magnetics",

issn = "0018-9464",

publisher = "Institute of Electrical and Electronics Engineers Inc.",

number = "6",

}

TY - JOUR

T1 - Effect of DNA coating on magnetic relaxation in γFc2O 3 nanoparticles

AU - Dutta, P.

AU - Seehra, M. S.

N1 - Funding Information: ACKNOWLEDGMENT This work was supported in part by the U.S. Department of Energy under Grant DE-FC26-05NT42456.

PY - 2007/6

Y1 - 2007/6

N2 - In this paper, we compare the magnetic relaxation of DNA-coated γFe2O3 with that of parent 7-nm γFe 2O3 particles by measuring the temperature dependence of AC susceptibilities (χ′ and χ″) at frequency f = 0.1, 1, 10, 100, and 1000 Hz and electron magnetic resonance (EMR) at 9.28 GHz. Changes in the blocking temperature TB (where χ′ peaks) with frequency are analyzed using the relation: TB = T0 + [T a/ln(f0/f)1 derived from Vogel-Fulcher relaxation, where Ta(T0) measures the effective energy barrier (interparticle interaction). The fit to the data yields f0 = 1.3 × 1016 Hz, Ta = 2760 K(2960 K), and T0 = 40 K(20 K) for the uncoated (DNA-coated) γFe2O3. From the relative shift ΔTm of Tm (the temperature where χ″ peaks) with change Δ log f in frequency, the parameterΦ = ΔTm/(Tm Δ log f) is determined to be 0.04(0.06) for the uncoated (coated) γFe 2O3. These results show only minimal changes in the magnetic dynamics of γFe2O3 upon DNA coating.

AB - In this paper, we compare the magnetic relaxation of DNA-coated γFe2O3 with that of parent 7-nm γFe 2O3 particles by measuring the temperature dependence of AC susceptibilities (χ′ and χ″) at frequency f = 0.1, 1, 10, 100, and 1000 Hz and electron magnetic resonance (EMR) at 9.28 GHz. Changes in the blocking temperature TB (where χ′ peaks) with frequency are analyzed using the relation: TB = T0 + [T a/ln(f0/f)1 derived from Vogel-Fulcher relaxation, where Ta(T0) measures the effective energy barrier (interparticle interaction). The fit to the data yields f0 = 1.3 × 1016 Hz, Ta = 2760 K(2960 K), and T0 = 40 K(20 K) for the uncoated (DNA-coated) γFe2O3. From the relative shift ΔTm of Tm (the temperature where χ″ peaks) with change Δ log f in frequency, the parameterΦ = ΔTm/(Tm Δ log f) is determined to be 0.04(0.06) for the uncoated (coated) γFe 2O3. These results show only minimal changes in the magnetic dynamics of γFe2O3 upon DNA coating.

KW - Biocompatibility

KW - Electron magnetic resonance

KW - Magnetic nanoparticles

KW - Magnetic relaxation

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