Two-photon excitation with pico-second fluorescence lifetime imaging to detect nuclear association of flavanols

[Display omitted] ► This fluorescence lifetime imaging microscopy (FLIM) technique for flavanols overcomes autofluorescence interference in cells. ► Plant flavanols differed in their lifetimes. ► Dissolved and bound flavanols revealed contrasting lifetime changes. ► This technique will allow studying of flavanol trafficking in live cells. Two-photon excitation enabled for the first time the observation and measurement of excited state fluorescence lifetimes from three flavanols in solution, which were ∼1.0ns for catechin and epicatechin, but