Synthesis of samarium orthoferrite-based perovskite nanoparticles as a turn-on fluorescent probe for trace level detection of picric acid

Abstract

Picric acid (2,4,6-trinitrophenol, PA) is a common constituent of many powerful explosives, thus, development of the chemical probes for trace level detection of PA is a crucial current challenge in both public security and environmental protection. In this work, the applicability of the new perovskite-type oxide SmFeO3 nanoparticles as an inorganic fluorescence turn-on probe for the selective and sensitive recognition of PA in organic and aqueous media was investigated. The synthesis of nanoparticles SmFeO3 was carried out using the surfactant-assisted templating approach which proceeds through the sol–gel process based on nonionic surfactant Triton X-100. The synthesized SmFeO3 nanoparticles exhibited strong solvent-dependent emission at 330 nm wavelength with absorption maxima at 225 nm. Among the tested explosives, the probe showed the highest sensitivity and selectivity for detecting PA in water and water/acetonitrile mixture. The response time for detecting PA was less than 5 s. The limits of detection for PA in acetonitrile and water/acetonitrile mixture were 2.1 µM and 1.1 µM, respectively. Furthermore, to investigate the nature of the fluorescence turn-on sensing mechanism, the experimental data of the dynamic light scattering (DLS) technique and zeta-potential were used. Both techniques confirmed the aggregation-induced emission (AIE) mechanism for detection of PA with the synthesized turn-on probe. The results of the present work will have a considerable impact on the development and applications of a new class of inorganic fluorescence turn-on probes for the detection of PA.