A novel molecularly imprinted fluorescent sensor for the determination of 4-nitroaniline (4-NA) was synthesized via free radical polymerization with 3-[(7-methoxy-2-oxo-2H-chromen-4-yl)methyl]-1-vinyl-1H-imidazol-3-ium bromide as the fluorescence functional monomer, 4-NA as the template molecule, ethylene glycol dimethacrylate as the cross-linker, and 2,2'-azo(bisisobutyronitrile) as the initiator. The obtained fluorescent poly(ionic liquid) was characterized through Fourier transform infrared, scanning electron microscopy, Brunauer-Emmett-Teller analysis, and fluorescence spectrophotometry. The fluorescent sensor had high fluorescence intensity, short detection time (0.5 min), good selectivity, and excellent sensitivity (limit of detection = 0.8 nM) for 4-NA, with good linear relationships of 2.67-10,000 nM. The practical applicability of the fluorescence sensor in detecting 4-NA in industrial wastewater and spiked environmental water was demonstrated, and a satisfactory result was obtained. Graphical abstract Highly sensitive and selective detection of 4-nitroaniline in water by a novel fluorescent sensor based on molecularly imprinted poly(ionic liquid).
Keywords: 4-Nitroaniline; Fluorescent sensor; Molecular imprinting; Poly(ionic liquid).