The perylene diimide (PDI) chromophore is a classic polycyclic aromatic hydrocarbon that has been widely used in the field of organic electronics. A combination of strong visible light absorption and...

Solvent specific intramolecular electronic communication truncated optical behaviour, and white light emission with a CIE chromaticity index of (0.33, 0.33) using only a single component via non-covalent nano-assembly of alkyne-phenanthrene conjugated perylenemonoimide (PMIAP) are demonstrated.

In recent years, the widely explored phenomenon “aggregation-induced emission (AIE)” has played a crucial role in the development of luminescent materials for light-emitting applications. In the same direction, the contribution of its sister concept “AIE switching” has been impressive. In comparison, the application of this concept in the field of biosensing or bioimaging is still in its infancy. Therefore, to shed light into the sensing of bioanalytes, we have developed a new perylenediimide (PDI)-based small fluorescent probe, benzoannulated PDI (Bp­(Im)2MA), that selectively detects diamines and biogenic amines (BAs) in solution via an “AIE-switching” phenomenon. The synthesized probe containing the bay-annulated anhydride moiety exhibits strong cyan emission in solution. In the mechanism, we have shown that the terminal free amine group of BAs readily reacts with a highly reactive anhydride moiety, which opens the cyclic anhydride moiety. In the open conformation, the free amine group along with a carboxylate group modulates the polarity of the system strikingly. Because of this induced polarity, the monomer of Bp­(Im)2MA-BAs conjugate aggregated in solution, thereby exhibiting a significant change in emission property in solution. This method may also be called a very simple and straightforward “naked eye” detection of BAs in solution, with a nanomolar detection limit. A detailed spectroscopic and microscopic investigation demonstrated the existence of the aggregated state. As the reporter dye also emits strongly in the solid state (yellowish orange), it therefore instantly made vapor-phase detection of BAs feasible. Finally, this vapor-phase detection of BAs by the probe was applied very effectively in the determination of spoilage of raw fish.

An efficient method for visible-light-triggered generation of radicals from mono- and dinitro-substituted perylenediimide derivatives is developed. UV-vis-NIR and electron paramagnetic resonance measurements were carried out to confirm the formation of radicals. Most importantly, these radical anions were remarkably stable for several months. Subsequently, the reversible nature of anions was validated by both chemical and spectroelectrochemical methods for applications in electrochromic materials.

The development of a water-soluble, perylenemonoimide (PMI) dye-doped polymer nanoparticle (PNP) with NIR emission for live-cell imaging is demonstrated. The large Stokes-shifted NIR emission is due to confined nanospace-induced aggregation offered by the polymer matrix. Later, folic acid functionalised PNP (PNP-FA) is successfully employed to differentiate folate receptor positive and negative cancer cells.