A novel long-wavelength fluorescent probe for discrimination of different palladium species based on Pd-catalyzed reactions

Abstract

We have synthesized a novel long-wavelength fluorescent probe MFC for detection of palladium (Pd⁰). This probe not only shows high selectivity for palladium, but also could quickly discriminate different palladium species (Pd⁰, Pd²⁺, Pd⁴⁺) in phosphate buffered solution. After the reaction with Pd(PPh₃)₄, the UV absorption of the probe MFC shifts from 334 nm to 594 nm within a few minutes. The probe MFC conjugated with alkyl carbamate, which destroys the principle of intramolecular charge transfer (ICT) and shows weak fluorescence. Based on the Pd⁰-catalyzed Tsuji–Trost deallylation reaction, the fluorogen was released and the fluorescence intensity at 612 nm was observed with 13-fold enhancement along with an obvious color change from yellow to purple with low detection limit.