A novel rhodamine-based dual probe Rh-2 for trivalent ferric ions (Fe3+) was successfully designed and synthesized, which exhibited a highly sensitive and selective recognition towards Fe3+ with an enhanced fluorescence emission in methanol-water media (v/v = 7/3, pH = 72). The probe Rh-2 could be applied to the determination of Fe3+ with a linear range covering from 3.0 x 10(-7) to 1.4 x 10(-5) M and a detection limit of 1.24 x 10(-8) M. Meanwhile, the binding ratio of Rh-2 and Fe3+ was found to be 1:1. Most importantly, the fluorescence and color signal changes of the Rh-2 solution were spec...