In living systems, subcellular organelles mutually cooperate and closely contact to form organelle interaction networks. Thus, the simultaneous and discriminative visualization of different organelles is extremely valuable for elucidating their distribution and interplay. However, such meaningful investigations remain a great challenge due to the lack of advanced single fluorescent probes (SFprobes) capable of simultaneous and two-color imaging of two targets. Herein, for the first time, we present two excited-state intramolecular proton transfer (ESIPT) based SF-probes (PPC and EPC) for simultaneous two-color fluorescence imaging of lipid droplets (LDs) and the endoplasmic reticulum (ER) under single-wavelength excitation. Due to the strong electron-donating ability of the side substituents, the fluorescence spectra and colors of these ESIPT probes are highly sensitive to the nuance of water contents between LDs and ER, leading to orange and green fluorescence in LDs and ER, respectively, in the Lambda imaging mode. Using the probe PPC or EPC, the morphology, size, and distribution of LDs and ER have been investigated in live cells and tissues. With the aid of in situ and real-time fluorescence imaging in Lambda mode, we observed the generation of newborn LDs near the ER regions and their close apposition and shared identical fluorescence colors, probably providing a valuable proof for the mainstream hypothesis that LDs originate from the ER. The remarkable imaging performances render these SF-probes as powerful tools to decipher LD-ER related biological processes.
We
report here the fluorescent sensing of both aromatic and linear
saturated dicarboxylate anions (DC2–
) (as their tetrabutylammonium salts) with different lengths and
shapes in acetonitrile using a single fluorescent probe, i.e., the
bis-calix[4]pyrrole-appended 9,14-diphenyl-9,14-dihydrodibenzo[a,c]phenazine (DPAC-bisC4P) incorporating a vibration-induced emission (VIE) phenazine core.
Fluorescence titration studies revealed that treating DPAC-bisC4P with dicarboxylate guests capable of forming pseudomacrocyclic host–guest
complexes via multiple hydrogen-bonding interactions between the dicarboxylates
and calix[4]pyrrole moieties led to a blue-shift in the emission of
the phenazine core. The binding-based fluorescence-tuning features
of DPAC-bisC4P allow the underlying binding events and
inferred structural changes to be monitored in the form of different
chromaticity outputs. The analyte-induced differences in the fluorescence
response to DC2–
cover a wide range
within the chromaticity diagram and can be visualized readily. The
present system thus functions as a rudimentary dicarboxylate anion
sensor. It highlights the potential benefits associated with combining
a tunable VIE core with noncovalent binding interactions and thus
sets the stage for the development of new fluorescent chemosensors
where a single chemical entity responds to different analytes with
a high level of tunability.
The emission response for vibration-induced emission luminogens is highly sensitive to the encountered steric hindrance during the planarization process such that a tiny structural variation could induce an obvious change in fluorescence.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.