A FRET based two-photon fluorescent probe for ratiometric detection of Pd2+ in living cells and in vivo

A ratiometric two-photon fluorescent probe (RN3) for Pd2+ was developed based on 7-substituted coumarin and rahodamine B through FRET mechanism. The probe exhibited highly sensitive and selective ratiometric fluorescent detection signal (575 nm/515 nm) for Pd2+ in aqueous solution. The two-photon absorption cross-section of the probe under adding Pd2+ was measured as 165 GM at 760 nm. RN3 could detect Pd2+ in living cells with low cytotoxicity under two-photon excitation (lambda(ex) = 760 nm). The bio-imaging results indicated that RN3 could work in deep tissue (similar to 130 mu m) and in five-days-old zebrafish with ratiometric fluorescent signal. (C) 2017 Elsevier B.V. All rights reserved.