Excited-state intramolecular proton-transfer (ESIPT) based fluorescence sensors and imaging agents

Abstract

We review recent advances in the design and application of excited-state intramolecular proton-transfer (ESIPT) based fluorescent probes. These sensors and imaging agents (probes) are important in biology, physiology, pharmacology, and environmental science.

Polarity‐Induced Excited‐State Intramolecular Proton Transfer (ESIPT) in a Pair of Supramolecular Isomeric Multifunctional Dynamic Metal–Organic Frameworks

“…[1][2][3][4] The most remarkable outcomeo fa nE SIPT-driven system is the broad,t unable, and dual emission, with al arge Stokes shift, that coversalarge part of the visible-light spectrum. [1][2][3][4] The most remarkable outcomeo fa nE SIPT-driven system is the broad,t unable, and dual emission, with al arge Stokes shift, that coversalarge part of the visible-light spectrum.…”

“…[1][2][3][4] The most remarkable outcomeo fa nE SIPT-driven system is the broad,t unable, and dual emission, with al arge Stokes shift, that coversalarge part of the visible-light spectrum. [1][2][3] For theser easons, materials that exhibit the ESIPT phenomenon have been successfully utilized in different optoelectronic applications, for example, in solar concentrators, [5] UV stabilizers, [6] photopatterning, [7] opticalm emory devices, [8] fluorescencei maging, [9] white-light emitters, [10,11] and smarto pticalw riters. Upon excitation, thet wo tautomeric forms give rise to two broad peaks.…”

“…[12] Besides all these smart applications, ESIPT systemsr esponsive to externals timuli can also be useful as fluorescentm oleculars witches, [13] which can be patternedin the fabrication of optical devices related to data recording, photodisplays, and light isolators(or light filters). [16] To date, ac onsiderable research on the ESIPT process has been carriedo ut with respect to real-time spectroscopic behavior [1][2][3][13][14][15] andt heoretical understanding [1][2][3][4]17] to identify the structure-property relationshipso fE SIPT systems. [15] Moreover, these polarity-sensitive materials could also be useful to chemically determine the polarityo fa nu nknown solvents ystem.…”

Aggregation‐Induced Emission‐Active 1,4‐Dihydropyridine‐Based Dual‐Phase Fluorescent Sensor with Multiple Functions

“…Organic stimulus‐responsive fluorescent molecules have been widely applied to the detection of cations, anions, and neutral molecules in the last two decades owing to their adaptability, simplicity of measurement, and high sensitivity and selectivity. Most of them are mainly used in liquid environments because traditional luminophores often suffer from aggregation‐caused quenching (ACQ) resulting from their structures containing planar π‐conjugated units.…”

Hydrazide–Hydrazone Small Molecules as AIEgens: Illuminating Mitochondria in Cancer Cells

“…[41,42] To validate the involvement of ESIPT and the role of dual intramolecular H-bonding in triggering AIE in compound 4a,w es ynthesized monohydroxy hydrazide-hydrazone compound 7 starting from 2-hydroxybenzoica cid (5)b yu sing the same synthetic strategy via 2-hydroxy benzohydrazide (6;F igure 4a). [41,42] To validate the involvement of ESIPT and the role of dual intramolecular H-bonding in triggering AIE in compound 4a,w es ynthesized monohydroxy hydrazide-hydrazone compound 7 starting from 2-hydroxybenzoica cid (5)b yu sing the same synthetic strategy via 2-hydroxy benzohydrazide (6;F igure 4a).…”