Pyrenyl‐Based Aggregation‐Induced Emission Luminogen for Highly Sensitive and Selective Detection of 2,4,6‐Trinitrotoluene in Water

Abstract

Trace detection of nitroaromatic explosives in aqueous solution is important for environmental pollution evaluation and terrorist prevention. Here, a new pyrenyl‐based aggregation‐induced emission (AIE) fluorochrome (CPPyV) with desirable fluorescent performance was synthesized and applied to detect 2,4,6‐trinitrotoluene (TNT) in water. The fluorescence of CPPyV can be selectivity and efficiently quenched by TNT. The Stern‐Volmer constant (KSV) of CPPyV for TNT was determined to be 6.2×105 M−1, with a low detection limit of 4 nM. Notably, CPPyV could be used for TNT determinations in real water samples and also developed as a fluorescent paper sensor which could efficiently detect TNT by naked‐eye when the TNT concentration was 1.0×10−8 M. The quenching process was dynamic quenching mechanism and the theoretical calculations revealed that photoin‐duced electron transfer (PET) from excited CPPyV to electron deficient TNT was the main reason for fluorescence quenching. The excellent detection performance of CPPyV yielded it a promising sensor material for actual field applications.

Potential applications of Aggregation Induced Emission active heterocyclic compounds

“…Hao et al reported a new pyrene-based AIE chromophore 2 which can be used as a sensor for nitroaromatic compounds in water since nitroaromatic explosives are used in the manufacture of explosive devices [50,51]. The developed probe 2 had a large, conjugated skeleton of pyrene moieties, which contributed to the appearance of fluorescence.…”

“…When the concentration of TNT was higher than 1 × 10 −8 M, considerable fluorescence quenching was detected. These findings showed that cheap probe sensors might be employed for real‐time field and visual TNT detection (Figure 2) [51].…”

“…From left to right, TNT concentrations 1.0 × 10 −5 , 1.0 × 10 −6 , 1.0 × 10 −7 , and 1.0 × 10 −8 M (A–D, respectively). Reproduced with permission [51]. Copyright 2021, Wiley.…”

To Quench or Not: Extending a β-Carboline Fluorophore for TNT Detection in Aqueous Media via Simultaneous ESPT Destabilization and AIE

“…Optical chemosensors relying on visible/fluorescence change upon TNT interaction offer a desirable alternative, mainly due to their low operational/instrumental requirements, ease of on-site applications, high sensitivity, and selectivity . Various types of fluorescent materials, such as small fluorophores, supramolecular systems, conjugated polymers, bioinspired materials, and aggregation-induced emission-active materials (AIEgens), have been used for the selective sensing of TNT. − …”

Thermo-Induced Fluorochromism in Two AIE Zinc Complexes: A Deep Insight into the Structure-Property Relationship

“…In TFC AIEgens the variation of PL behaviour is caused by a thermal treatment inducing a molecular rearrangement [17,27,28]. Both MFC and TFC AIEgens have been used for advanced applications such as display devices, sensing, and optical data storage [17,24,[29][30][31][32][33][34][35][36][37][38]. Obviously, the structure-responsiveness relationship is critical for the prediction and understanding of AIEgens' fluorochromic response.…”