A luminescent organic cocrystal for detecting 2,4-dinitroaniline

Talanta. 2024 Jun 1:273:125919. doi: 10.1016/j.talanta.2024.125919. Epub 2024 Mar 19.

Abstract

2,4-dinitroaniline (2,4DNBA), a significant hazardous chemical, is extensively used in industry and agriculture. The chemical accumulates in the environment for a long time, causing irreversible damage to the ecosystem. Currently, it is quite challenging to identify it by common analysis and detection techniques. Herein, a luminescent organic cocrystal (TCNB-8HQ) was prepared using 1,2,4,5-tetracyanobenzene (TCNB) as the electron acceptor and 8-hydroxyquinoline (8HQ) as the electron donor. The prepared TCNB-8HQ was used as a fluorescent probe with a fast and specific response to 2,4DNBA. This detection method possessed a linear range of 0.5-200 μmol/L with a detection limit as low as 0.085 μmol/L to detect 2,4DNBA in real samples with satisfactory spiking recovery. As revealed by fluorescence spectrum and UV-vis absorption spectrum, the detection mechanism involved competitive absorption between cocrystal material and 2,4DNBA. Moreover, the feasibility of the system was explored by preparing portable indicator strips for 2,4DNBA from organic cocrystal (TCNB-8HQ). This study not only provided an environmentally friendly gram-level preparation strategy to synthesize the fluorescent material but also investigated their application in chemical detection.

Keywords: 1,2,4,5-Tetracyanobenzene; 2,4-Dinitroaniline; Charge transfer; Competitive absorption; Fluorescence probe; Organic cocrystal.