Europium-doped gadolinium sulfide nanoparticles as a dual-mode imaging agent for T1-weighted MR and photoluminescence imaging.

Abstract We present a facile synthesis of europium-doped gadolinium sulfide (GdS:Eu 3+ ) opto-magnetic nanoparticles (NPs) via sonochemistry. Their photoluminescence and strong paramagnetic properties enable these NPs to be utilized as an in vitro cell imaging and in vivo T 1 -weighted MR imaging probe. The GdS:Eu 3+ NPs have a prominent longitudinal ( r 1 ) relaxivity value, which is a critical parameter for T 1 -weighted MR imaging. Here, we showed not only their strong positive contrast effect to blood vessels and organs of mice, but also blood half-life and biodistribution including clearance from organs, in order to assess the GdS:Eu 3+ NPs as a competent nanocrystal-based T 1 contrast agent. We further showed confocal images of breast cancer cells containing GdS:Eu 3+ NPs to evaluate as a photoluminescence probe. Dual-mode imaging capability obtained from the GdS:Eu 3+ NPs will allow target-oriented cellular imaging as well as the resulting disease-specific MR imaging.