One-pot synthesis of multifunctional radiolabeled upconversion nanorods for enhanced multimodal imaging performance

Abstract

We report on the synthesis of radiolabeled NaYF₄:Yb/Er/Gd (18/2/60 mol%) upconversion nanorods (UCNRs) by a one-pot solvothermal process. The synthesized UCNRs were transferred to water by using poly(maleic anhydride-alt-1-octadecene)-mPEG 5000 (C18PMH-PEG). Subsequently nuclide ¹²⁵I⁻ was added as a label through the chloramine-T method to obtain the desired ¹²⁵I-UCNR nanoprobe. Our study showed that the radiolabeled UCNRs exhibited excellent colloidal stability, along with exceptional T₁ contrast enhancement, intense upconversion emission and the SPECT signal in pancreas. This implies their potential use as a single-phase system for fluorescence, T₁-MR and SPECT imaging, which in turn highlights the characteristics of the current multifunctional nanoagents and their use in clinical translation.