r 1 and r2/r1 values for various Gd2O3 nanosystems, a free Gd3+ ion, and Gd-DTPAa.
| Chemical | Particle diameter (nm) | Ligand | Temperature (°C) | Applied field (T) | r 1 (s−1 mM−1) | r 2/r1 | Ref. |
|---|---|---|---|---|---|---|---|
| Gd3+ | — | DTPA | 19.5 | 1.5 | 4.1 | 1.1 | 6 |
| Free Gd3+ | — | — | 19.5 | 1.5 | 10.5 | 1.2 | 6 |
| Gd2O3 nanoplate | 2 | Oleic acid | — | 1.41 | 8.0 | 3.3 | 14 |
| Gd2O3 nanoplate | 2 | PAA–OA | — | 1.41 | 47.2 | 1.7 | 14 |
| Gd2O3 nanoparticle | 3–5 | Mal-PEG-NHS-MPTS | 22 | 1.5 | 22.8 | 1.4 | 15 |
| Gd2O3 nanoparticle | 20–40 | Dextran | 37 | 7.05 | 4.8 | 3.5 | 35 |
| Gd2O3 nanoparticle | 2.0 | PAA | 22 | 1.5 | 31.0 | 1.2 | This work |
a
DTPA: diethyleneaminepentaacetic acid. Mal-PEG-NHS-MPTS: α-maleinimido-ω-carboxysuccinimidyl ester poly(ethylene glycol)-(3-mercaptopropyl)tri-methoxysilane. PAA–OA: polyacrylic acid–octylamine.