Achieving purely organic room temperature phosphorescence in aqueous solution

Abstract

Purely organic room temperature phosphorescence (RTP) materials have aroused increasing interests in recent years and have been widely applied in anticounterfeiting, biological imaging, sensing, etc. Currently, these materials can be efficiently developed in crystalline states and amorphous polymer-doped systems. However, achieving organic RTP in solution, especially in water solution, is still a formidable challenge. Recently, reports on aqueous phase RTP have been increasing and some feasible design strategies have been proposed; however, related investigations are still limited and there is a lack of systematic reviews. Therefore, we summarized the recent cases of aqueous phase organic RTP emission with primarily focusing on the RTP properties and efficient design strategies (e.g., forming nanoparticles from phosphorescent molecules and macrocyclic supramolecular assembly). Moreover, promising applications of the aqueous phase organic RTP emission in bio-imaging and sensing were discussed. Some detailed perspectives concerning materials design and application were provided with the hope to provide inspiration for the future development of aqueous phase organic RTP.

A proton-assisted AIE active luminescent material having tunable emission in solution and solid state for anti-counterfeiting application: smart high contrast on–off–on fluorescence switch

“…Among all the most widely used techniques for averting counterfeiting, fluorescent security ink, having the property of invisibility under both UV and visible radiations as a tag, is the tempting one to achieve a high level of security. [36][37][38][39] The above findings emphasize to design and develop a new anti-counterfeiting material using DPABHz, which shows the remarkable luminescence response aroused by an acid. Thus, two drops of a solution of DPABHz (10 À5 M in THF) were dropped on a piece of TLC plate, and both of them were invisible under both daylight and UV radiation.…”

Stimulus-Responsive Organic Phosphorescence Materials Based on Small Molecular Host–Guest Doped Systems

“…Water is usually considered as a phosphorescence quencher because of the intermolecular interactions of phosphors that can be easily broken in aqueous environments . In addition, the excitation energy can be further dissipated by dissolved oxygen in water and solvent-assisted relaxation . However, the water molecule embedded in the vicinity of the matrix promotes rigidification of the matrices and suppression of nonradiative decays by forming H-bonding networks for efficient RTP emission .…”

Aqueous Room‐Temperature Phosphorescence from Assembled Phosphors for Analytical Detection†

“…In this regard, self‐assembly of small molecular phosphors in dual phases (good and bad solvents) to form organic nanoparticles has been demonstrated as an effective approach for inducing aqueous RTP. Since the related progress was already systematically reviewed recently, [ 59 ] here we focused on non‐covalent interaction‐induced assembly, e.g ., hydrogen bonding‐induced assembly. Currently, hydrogen bonding‐induced assembly has been considered as a general strategy to restrict molecular motions, thus generating rigid environment for stabilizing the triplet excitons and boosting RTP.…”