Fig. 1

Characterization of PEG–TRITC–Gd₂O₃–MSN. a Schematic showing multifunctional MSN particle with Gd₂O₃ incorporated into silica matrix, and FITC or TRITC grafted onto the silica surface, followed by poly(ethylene glycol). b Powder X-ray diffraction patterns of TRITC–Gd₂O₃–MSN after surfactant removal. The intense peak at 2.5 2θ is characteristic of hexagonally arranged pores in MSN. c Transmission electron micrograph of synthesized MSN, with higher magnification inset (d), and fully synthesized PEG–TRITC–Gd₂O₃–MSN (e). Visualized particles had a uniform size distribution and showed no formation of aggregates. f Hydrodynamic size distribution of PEG-TRITC–Gd₂O₃–MSN as measured by dynamic light scattering. The primary peak has a median particle size of 187.3 nm. Scale bars indicate 100 nm