Highly fluorescent 2D-BCNO sheets based chemical sensor for selective detection of the explosive Dunnite and 4-nitrophenol in aqueous medium

Abstract

Highly fluorescent 2D-BCNO (boron carbon oxynitride) sheets were synthesized via a new facile and simple approach for selective and sensitive detection of nitro-aromatic compounds, namely 4-nitrophenol and Dunnite, in aqueous medium. 2D-BCNO sheets exhibited strong blue fluorescence emission in aqueous medium. The detailed photophysical properties and pH-dependent studies were performed. 2D-BCNO sheets showed a high fluorescence quenching towards explosive nitro-analytes and showed an unprecedented selectivity for Dunnite and 4-nitrophenol with a limit of detection (LOD) of 2.1 and 0.22 ppb respectively. The remarkable sensitivity during the fluorescence quenching phenomena arose due to the unique inner filter effect (IFE) and photo-induced electron transfer process through electrostatic interactions. The promising results from real-time sample analysis of river and tap water as well as interference studies in the presence of other nitro-analytes elucidated the potential practical application of sensor technology based on the 2D-BCNO sheets. Furthermore, the rapid and visual identification of Dunnite and 4-nitrophenol at picogram levels with a contact mode approach on solid substrates demonstrated that the developed sensor technology is suitable for onsite field analysis.