A fluorescent and colorimetric probe specific for palladium detection.

A selective Pd probe is described, which shows fluorometric and colorimetric responses towards both Pd(2+) ions and Pd(0)-complexes with excellent sensitivity and potential application. The fluorescence quenching effect of Pd(2+) is inhibited by filling up d-orbitals after the reduction from Pd(2+) (open-shell) to Pd(0) (closed-shell).