“Metal-Free” Fluorescent Supramolecular Assemblies for Distinct Detection of Organophosphate/Organochlorine Pesticides

Abstract

The “metal-free”, easy-to-prepare fluorescent supramolecular assemblies based on anthracene/perylene bisamide (PBI) derivatives have been developed for the distinct detection of organophosphate (CPF) and organochlorine (DCN) pesticides in aqueous media. The supramolecular assemblies of anthracene derivative show rapid and highly selective “on–on” response toward organophosphate (CPF), which is attributed to the formation of CPF-induced formation of “closely packed” assemblies. A detection limit in the nanomolar range is observed for CPF. On the other hand, the inner filter effect is proposed as the mechanism for the “on–off” detection of DCN using supramolecular assemblies of the anthracene derivative. This is the first report on the development of fluorescent materials having the potential to differentiate between organophosphate and organochlorine pesticides. The assemblies of anthracene derivative 2 also act as “enzyme mimic” as organophosphate pesticide show a preferential affinity for assemblies of derivative 2 over acetylcholinesterase enzyme. Further, the real-time applications of supramolecular assemblies have also been explored for the detection of CPF and DCN in spiked water and in agricultural products such as grapes and apples.