Herein, we report the use of two-photon fluorogenic probes using tetrazine-based bioorthogonal reactions with multicolor emissions that cover nearly all of the visible region. New fluorogenic probes were designed based on donor-acceptor-type naphthalene structures conjugated with a fluorescence-quenching tetrazine moiety for turn-on properties in one- and two-photon fluorescence. Our fluorescent probes showed a moderate to good turn-on ratio after bioorthogonal inverse electron demand Diels-Alder cycloaddition with trans-cyclooctenol in one- and two-photon fluorescence. We successfully applied our probes to mitochondria- and lysosome-selective bioorthogonal imaging in live cells with one-/two-photon and one-photon microscopy, respectively.
This work was supported by the National Creative Research Initiative Grant (2014R1A3A2030423) and the Bio & Medical Technology Development Program (2012M3A9C4048780) through the National Research Foundation of Korea (NRF) funded by the Korean Government (Ministry of Science & ICT). D.K. is grateful for the BK21 Predoctoral Fellowship Program.
