Photooxidation-Driven Purely Organic Room-Temperature Phosphorescent Lysosome-Targeted Imaging

Abstract

The construction of host–guest-binding-induced phosphorescent supramolecular assemblies has become one of increasingly significant topics in biomaterial research. Herein, we demonstrate that the cucurbit[8]­uril host can induce the anthracene-conjugated bromophenylpyridinium guest to form a linear supramolecular assembly, thus facilitating the enhancement of red fluorescence emission by the host-stabilized charge-transfer interactions. When the anthryl group is photo-oxidized to anthraquinone, the obtained linear nanoconstructs can be readily converted into the homoternary inclusion complex, accompanied by the emergence of strong green phosphorescence in aqueous solution. More intriguingly, dual organelle-targeted imaging abilities have been also distinctively achieved in nuclei and lysosomes after undergoing photochemical reaction upon UV irradiation. This photooxidation-driven purely organic room-temperature phosphorescence provides a convenient and feasible strategy for supramolecular organelle identification to track specific biospecies and physiological events in the living cells.

A tunable phosphorescence supramolecular switch by an anthracene photoreaction in aqueous solution

“…However, there are few reports on purely organic RTP molecular switches with stimulus responsiveness. 59–61 Ma and Ding et al realized photo-controllable purely organic RTP based on the photochromic polymer by synthesizing two polymers containing hexaaryldiimidazole and using their reversible homolysis to form triphenylimidazole radicals under UV irradiation. 62…”

Supramolecular assembly confined purely organic room temperature phosphorescence and its biological imaging

“…Therefore, a bromophenylpyridinium salt was conjugated at the 2-position of anthracene ( Fig. 12 ), 36 and the resultant compound displayed weak fluorescence emission at 500 nm. After adding CB[8], linear supramolecular aggregates were formed, and the fluorescence became stronger and red-shifted to 613 nm.…”

Unprecedented and Readily Tunable Photoluminescence from Aliphatic Quaternary Ammonium Salts**

“…The impressive PL properties of TMAB and CTAB indicate that QASs can be competitive candidates for the generation of efficient (p-)RTPs, which are currently being extensively studied in aromatics. [34][35][36][37][38][39][40][41][42][43][44][45] Considering the strong Coulombic interactions between halogen counterions (X À ) and positively charged quaternary N moieties (N + ), heavy halogen ions should play important roles in the formation of clustered chromophores. Moreover, they can considerably enhance the SOC and subsequent ISC processes due to the clustering effect [46] and the renowned heavy-atom effect.…”