Development of bi-oligo (ethylene glycol)-functionalized fluorescent probe for two-photon and noninvasive imaging in Arabidopsis thaliana

Fluorescent probe is an important tool for investigation of biological events in plant tissues. However, the research on small-molecule based fluorescent probe for plant imaging still stays at the initial stage. In order to noninvasively achieve the subcellular information of Arabidopsis thaliana, a two-photon and fluorene based fluorophore with a bi-oligo (ethylene glycol) functional group was synthesized. Under the laser's irradiation at 750 nm, the subcellular structures of Arabidopsis thaliana including stomata and root tips were clearly observed without slicing, which displayed significant superiorities over traditional single-photon excitation microscopy. Subsequently, the above functionalized fluorophore was further modified with a recognition group (dipicolylamine) to form a smart fluorescent probe (LJTP1). As results, LJTP1 not only can sensitively detect Cu2+/S2− with fluorescence “on-off-on” response in vitro and in vivo, but also can achieve noninvasive imaging in Arabidopsis thaliana tissues under two-photon microscopy. We believe this study will open up a new mind for noninvasive imaging in plant tissues.