title: Influence of magnetoplasmonic γ-Fe2O3/Au core/shell nanoparticles on low-field nuclear magnetic resonance.
abstract: Magnetoplasmonic nanoparticles, composed of a plasmonic layer and a magnetic core, have been widely shown as promising contrast agents for magnetic resonance imaging (MRI) applications. However, their application in low-field nuclear magnetic resonance (LFNMR) research remains scarce. Here we synthesised γ-Fe2O3/Au core/shell (γ-Fe2O3@Au) nanoparticles and subsequently used them in a homemade, high-Tc, superconducting quantum interference device (SQUID) LFNMR system. Remarkably, we found that both the proton spin-lattice relaxation time (T1) and proton spin-spin relaxation time (T2) were influenced by the presence of γ-Fe2O3@Au nanoparticles. Unlike the spin-spin relaxation rate (1/T2), the spin-lattice relaxation rate (1/T1) was found to be further enhanced upon exposing the γ-Fe2O3@Au nanoparticles to 532 nm light during NMR measurements. We showed that the photothermal effect of the plasmonic gold layer after absorbing light energy was responsible for the observed change in T1. This result reveals a promising method to actively control the contrast of T1and T2in low-field (LF) MRI applications.
authors.affiliation: Department of Physics, National Chung Hsing University, Taichung 402, Taiwan.
authors.forename: Kuen-Lin
authors.initials: KL
authors.lastname: Chen
authors.affiliation: Department of Physics, National Chung Hsing University, Taichung 402, Taiwan.
authors.forename: Yao-Wei
authors.initials: YW
authors.lastname: Yeh
authors.affiliation: Institute of Nanoscience, National Chung-Hsing University, Taichung 402, Taiwan.
authors.forename: Jian-Ming
authors.initials: JM
authors.lastname: Chen
authors.affiliation: Department of Physics, National Chung Hsing University, Taichung 402, Taiwan.
authors.forename: Yu-Jie
authors.initials: YJ
authors.lastname: Hong
authors.affiliation: Department of Physics, National Chung Hsing University, Taichung 402, Taiwan.
authors.forename: Tsung-Lin
authors.initials: TL
authors.lastname: Huang
authors.affiliation: Department of Physics, National Chung Hsing University, Taichung 402, Taiwan.
authors.forename: Zu-Yin
authors.initials: ZY
authors.lastname: Deng
authors.affiliation: Department of Physics, National Chung Hsing University, Taichung 402, Taiwan.|Institute of Nanoscience, National Chung-Hsing University, Taichung 402, Taiwan.
authors.forename: Chiu-Hsien
authors.initials: CH
authors.lastname: Wu
authors.affiliation: Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei 116, Taiwan.
authors.forename: Su-Hsien
authors.initials: SH
authors.lastname: Liao
authors.affiliation: Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Wang