Characterization of single-core magnetite nanoparticles for magnetic imaging by SQUID relaxometry.
Characterization of single-core magnetite nanoparticles for magnetic imaging by SQUID relaxometry.
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DOI：
10.1088/0031-9155/55/19/023
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发表时间：
2010-10-07
影响因子：
3.5
通讯作者：
Flynn ER
中科院分区：
文献类型：
--
作者：
Adolphi NL;Huber DL;Bryant HC;Monson TC;Fegan DL;Lim J;Trujillo JE;Tessier TE;Lovato DM;Butler KS;Provencio PP;Hathaway HJ;Majetich SA;Larson RS;Flynn ER
优化SQUID（超导量子干涉装置）的灵敏度-弛豫法用于检测用于体内诊断的细胞靶向磁性纳米颗粒，需要具有窄粒度分布的纳米颗粒，以确保Néel弛豫时间落在测量时间范围内（在这项工作中为50 ms - 2 s）。为了确定最佳的粒径，单核磁铁矿纳米颗粒（标称平均直径20，25，30和35 nm），其特征在于SQUID-弛豫法，透射电子显微镜（TEM），SQUID-光散射，动态光散射，和zeta电位分析。来自25 nm和30 nm颗粒的SQUID-弛豫信号（检测到的磁矩/kg）是对先前研究的多核颗粒的改进。然而，检测到的时刻是一个数量级低于预测的基础上，考虑到测量的尺寸分布（但忽略偶极相互作用和各向异性能量密度的多分散性）的一个简单的模型，这表明，改善控制的几个不同的纳米粒子的性能（大小，形状，涂层厚度）将需要实现最高的检测灵敏度。抗体偶联和细胞孵育实验表明，单核颗粒能够实现每个细胞更高的检测矩，但也证明需要改进的表面处理以减轻聚集和提高特异性。
Optimizing the sensitivity of SQUID (superconducting quantum interference device)-relaxometry for detecting cell-targeted magnetic nanoparticles for in vivo diagnostics requires nanoparticles with a narrow particle size distribution to ensure that the Néel relaxation times fall within the measurement timescale (50 ms - 2 s, in this work). To determine the optimum particle size, single-core magnetite nanoparticles (with nominal average diameters 20, 25, 30, and 35 nm) were characterized by SQUID-relaxometry, transmission electron microscopy (TEM), SQUID-susceptometry, dynamic light scattering, and zeta potential analysis. The SQUID-relaxometry signal (detected magnetic moment/kg) from both the 25 nm and 30 nm particles was an improvement over previously-studied multi-core particles. However, the detected moments were an order of magnitude lower than predicted based on a simple model that takes into account the measured size distributions (but neglects dipolar interactions and polydispersity of the anisotropy energy density), indicating that improved control of several different nanoparticle properties (size, shape, coating thickness) will be required to achieve the highest detection sensitivity. Antibody conjugation and cell incubation experiments show that single-core particles enable a higher detected moment per cell, but also demonstrate the need for improved surface treatments to mitigate aggregation and improve specificity.
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影响因子：
3.5
作者：
Romanus, E;Berkov, DV;Weber, P
通讯作者：
Weber, P
影响因子：
--
作者：
BROWN, WF
通讯作者：
BROWN, WF
影响因子：
2.7
作者：
Huber, DL;Venturini, EL;Patel, RJ
通讯作者：
Patel, RJ
DOI：
10.1088/0022-3719/21/10/019
发表时间：
1988-04-10
期刊：
JOURNAL OF PHYSICS C-SOLID STATE PHYSICS
影响因子：
--
作者：
DORMANN, JL;BESSAIS, L;FIORANI, D
通讯作者：
FIORANI, D
影响因子：
2.7
作者：
Ferguson RM;Minard KR;Krishnan KM
通讯作者：
Krishnan KM