关键字：Iron oxides;Body fluids - Deterioration - Harmonic analysis - Magnetite - Nanoparticles - Positive ions - Quantum theory - Trace elements
摘要：In this work, well-defined 3 nm-sized Ca²⁺, Fe³⁺, Na⁺, Mg²⁺, Zn²⁺, Ni²⁺, Co²⁺, and Cd²⁺ cation-adsorbed Fe<inf>3</inf>O<inf>4</inf>/γ-Fe<inf>2</inf>O<inf>3</inf> nanoparticles were used as prototype systems to investigate the influence of metallic trace elements in body fluids on the relaxivities of iron-oxide contrast agents. It was found that surface-adsorbed cations formed a deterioration layer to induce pronounced relaxivity loss. Theoretical study showed that such relaxivity loss can be well described by a modified GCAS function, taking into account the harmonic cation oscillations around Fe<inf>3</inf>O<inf>4</inf>/γ-Fe<inf>2</inf>O<inf>3</inf> nanoparticles. Quantum mechanics analyses revealed that even-parity and odd-parity states of harmonic oscillations are dominant in r<inf>1</inf> and r<inf>2</inf> relaxivities, respectively. Moreover, the harmonic oscillations of Na⁺ and Mg²⁺ cations around Fe<inf>3</inf>O<inf>4</inf>/γ-Fe<inf>2</inf>O<inf>3</inf> nanoparticles are found to be classical forbidden, which are quite different from their counterparts located in the classical permissive area.<br/> © 2019 The Royal Society of Chemistry.
卷号：9
期号：53
是否译文：否