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 T1 and T2 in low-field (LF) MRI applications.

Enhancement of Magnetic Hyperthermia by Mixing Synthetic Inorganic and Biomimetic Magnetic Nanoparticles

“…In spite of the certainly wide variety of magnetic nanoparticles (MNPs) with different geometries, compositions and functionalizations [1,2,3,4,5,6,7,8] that have become available in recent years, and of the number of applications that have been devised for them [1,9,10,11,12], when the goal is to provide a nanocarrier suitable for targeted chemotherapy, there is still room for progress. On one hand, the methods for obtaining MNPs need to be more cost- and time-effective, eco-friendly, and scalable.…”

The Response of UV/Blue Light and Ozone Sensing Using Ag-TiO2 Planar Nanocomposite Thin Film

“…Different metal nanoparticles (Ag, Au) doped on MOSs are widely used in many fields to generate SPR and enhance photocatalysis; they are also used in gas sensors, environmental protection technologies, solar cells, energy storage devices, and photoelectric materials [17,18,19]. For example, researchers have applied SPR with magnetic microspheres for prion protein detection [20,21,22], a magnetic biochip (Au/Fe 2 O 3 /Au) for antigen detection [23], core-shell γ -Fe2O3@Au nanoparticles for low-field nuclear magnetic resonance [24], a gold film-coated side-polished fiber for temperature sensor fabrication [25], and Au@SiO 2 core-shell NPs into TiO 2 scaffold layer to increase the power conversion efficiency of solar cells [26].…”

Controlling the transverse proton relaxivity of magnetic graphene oxide

“…In pursuit of high-performance MRI CAs, the surface modification of IO is mostly executed in the form of core-shell 18,19 and Janus structure 20 using polymer stabilizers along with their controlled shape and size. In addition, with the advances in the research of graphene-based materials, GO has been utilized for surface modification of IO owing to its oxygenated functionalities, i.e., epoxide, hydroxyl, carbonyl, and carboxyl moieties 21,22 and biocompatibility 23,24 .…”