A flavonoid-based light-up bioprobe with intramolecular charge transfer characteristics for wash-free fluorescence imaging in vivo

Abstract

Wash-free imaging methods can simplify the experimental procedures and facilitate the continuous observation of the targets by eliminating washing process. In this work, we present a flavonoid-based light-up bioprobe with intramolecular charge transfer characteristics. The probe could be easily synthesized by the methylation of its flavone derivative, which was initially prepared via the Claisen-Schmidt condensation and Algar-Flynn-Oyamada reaction. The probe possessed a large Stokes shift, positive solvatochromism, high photostability, high tolerance for metal ions, and light-up fluorescence properties towards protein and tissue lysate. Moreover, the signal-to-noise ratio of fluorescence bioimaging in living cells and zebrafish by using this probe could reach 4–15 without washing process, providing a new candidate for efficient wash-free imaging method in vivo.