Rhodamine–Pyridyl Probe: A Selective Optical Reporter for Biologically Important Zn2+

A new Rhodamine-based probe, Rhoda-P affords remarkably selective chromo- and fluorogenic responses in the presence of Zn2+ with the color turning from colorless (λmax=302 nm) to orange (λmax=528 nm) and the fluorescence output increased by 160-fold at 1.5×10−3 M of Zn2+. In contrast, Li+, Na+, K+, Ba2+, Ca2+, Mg2+, Co2+, Ni2+, Cu2+, and Cd2+ did not significantly alter the photophysical properties of the probe even at relatively higher concentrations than Zn2+.