Differential Magnetic Catch and Release: Analysis and Separation of Magnetic Nanoparticles

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• 作者：Jacob S. Beveridge ; Jason R. Stephens ; Andrew H. Latham ; Mary Elizabeth Williams
• 刊名：Analytical Chemistry
• 出版年：2009
• 出版时间：December 1, 2009
• 年：2009
• 卷：81
• 期：23
• 页码：9618-9624
• 全文大小：387K
• 年卷期：v.81,no.23(December 1, 2009)
• ISSN：1520-6882

文摘

This article reports the purification and separation of magnetic nanoparticle mixtures using differential magnetic catch and release (DMCR). This method applies a variable magnetic flux orthogonal to the flow direction in an open tubular capillary to trap and controllably release magnetic nanoparticles. Magnetic moments of 8, 12, and 17 nm diameter CoFe₂O₄ nanoparticles are calculated using the applied magnetic flux and experimentally determined force required to trap 50% of the particle sample. Balancing the relative strengths of the drag and magnetic forces enables separation and purification of magnetic CoFe₂O₄ nanoparticle samples with <20 nm diameters. Samples were characterized by transmission electron microscopy to determine the average size and size dispersity of the sample population. DMCR is further demonstrated to be useful for separation of a magnetic nanoparticle mixture, resulting in samples with narrowed size distributions.