Synthesis of two-dimensional bismuth molybdenum oxide (2D-BMO) nanosheets and their application as fluorescent probes for the detection of explosive nitroaromatic compounds

Abstract

2D-BMO fluorescent nanosheets were synthesized using a solvothermal method followed by probe sonication. These nanosheets were then employed as fluorescent probes for detecting nitroaromatic compounds picric acid (PA) and 2,4-dinitrophenylhydrazine (2,4-DNPH), which have recently garnered significant attention due to their explosive nature and environmental impact. The fluorescent nanoplatform exhibited stable fluorescence emission at a wavelength of 400 nm (λ_em) when excited at 340 nm (λ_ex). The fluorescence quenching response towards PA and 2,4-DNPH was assessed within a concentration range of 50 to 2000 nM, showing linear responses within the ranges of 50–1100 nM and 50–1400 nM, respectively. The limits of detection were determined to be 2.21 nM for PA and 2.30 nM for 2,4-DNPH, with corresponding R² values of 0.999 and 0.994. The interaction between the 2D-BMO nanosheets and nitroaromatics was the synergistic combination of the FRET, IFE, and electrostatic interaction, which was studied and explained by UV-visible absorption spectroscopy and zeta potential analysis. This 2D-BMO fluorescent sensor could pave the way for replacing traditional dyes that pose significant harm to the environment in the foreseeable future.