Precision picric acid detection via a fluorenone-amide functionalized fluorescent micellar probe

Abstract

Detection of picric acid (PA) in aqueous solutions is crucial for pollution control, extending beyond national security and military applications. Herein, a binary ensemble AM@SDS has been assembled by encapsulating a fluorenone functionalized amide-based probe (AM) within the micelles of an anionic surfactant, sodium dodecyl sulphate (SDS) in an aqueous medium. A range of spectroscopic techniques, including high-resolution transmission electron microscopy (HRTEM), dynamic light scattering (DLS), and fluorescence spectroscopy (FL), have been employed to characterize the formation of micelles of AM@SDS. A remarkable increase in fluorescence intensity was observed upon interactions of AM with the microenvironment of SDS micelles. Conversely, the fluorescence intensity at 358 nm was significantly quenched in the presence of PA compared to other nitroaromatic compounds (NACs). The detection limit for PA was found to be 368 nM. Furthermore, the binary ensemble AM@SDS has demonstrated remarkable efficacy in detecting PA in real water samples from diverse sources such as lake, river, and tap water, achieving an exceptional recovery rate of up to 99.9 %.