Rapid Nucleation of Iron Oxide Nanoclusters in Aqueous Solution by Plasma Electrochemistry

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• 作者：Mathieu Bouchard ; Mathieu L茅tourneau ; Christian Sarra-Bournet ; Myriam Laprise-Pelletier ; St茅phane Turgeon ; Pascale Chevallier ; Jean Lagueux ; Ga茅tan Laroche ; Marc-A. Fortin
• 刊名：Langmuir
• 出版年：2015
• 出版时间：July 14, 2015
• 年：2015
• 卷：31
• 期：27
• 页码：7633-7643
• 全文大小：559K
• ISSN：1520-5827

文摘

Progresses in cold atmospheric plasma technologies have made possible the synthesis of nanoparticles in aqueous solutions using plasma electrochemistry principles. In this contribution, a reactor based on microhollow cathodes and operating at atmospheric pressure was developed to synthesize iron-based nanoclusters (nanoparticles). Argon plasma discharges are generated at the tip of the microhollow cathodes, which are placed near the surface of an aqueous solution containing iron salts (FeCl₂ and FeCl₃) and surfactants (biocompatible dextran). Upon reaction at the plasma鈥搇iquid interface, reduction processes occur and lead to the nucleation of ultrasmall iron-based nanoclusters (IONCs). The purified IONCs were investigated by XPS and FTIR, which confirmed that the nucleated clusters contain a highly hydrated form of iron oxide, close to the stoichiometric constituents of 伪-FeOOH (goethite) or Fe₅O₃(OH)₉ (ferrihydrite). Relaxivity values of r₁ = 0.40 mM^鈥? s^鈥? and r₂/r₁ = 1.35 were measured (at 1.41 T); these are intermediate values between the relaxometric properties of superparamagnetic iron oxide nanoparticles used in medicine (USPIO) and those of ferritin, an endogenous contrast agent. Plasma-synthesized IONCs were injected into the mouse model and provided positive vascular signal enhancement in T₁-w. MRI for a period of 10鈥?0 min. Indications of rapid and strong elimination through the urinary and gastrointestinal tracts were also found. This study is the first to report on the development of a compact reactor suitable for the synthesis of MRI iron-based contrast media solutions, on site and upon demand.