Selective fluorescence sensing of 3,5-dinitrosalicylic acid based on pyrenesulfonamide-functionalized inorganic/organic hybrid nanoparticles

Abstract Pyrenesulfonamide-functionalized inorganic/organic hybrid Fe 3 O 4 @SiO 2 nanoparticles were prepared for the selective and sensitive detection of 3,5-dinitrosalicylic acid (3,5-DNSA) among a series of aromatic carboxylic acids. The monomer fluorescence emission intensity of pyrene at 380 nm was switched off on interaction with 3,5-DNSA. The minimum detection limit for 3,5-DNSA was 10 nM in 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES)–CH 3 CN (8:2; pH 7.4). The inorganic/organic hybrid Fe 3 O 4 @SiO 2 nanoparticles were characterized using Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy.