Fig 2.

Relaxivity of GdDOTA-diBPYREN at 23 MHz and 37 °C in the presence of MCl₂, where M = Zn²⁺, Cu²⁺, Ca²⁺, or Mg²⁺. All solutions were prepared in 100 mM Tris buffer at pH 7.6. r₁ was determined from the slope of the line of the reciprocal of T₁ versus the concentration of gadolinium (GdDOTA- diBPYREN was varied from 1 to 5 mM).