Highly sensitive and selective detection of 4-nitroaniline in water by a novel fluorescent sensor based on molecularly imprinted poly(ionic liquid)

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-2 H -chromen-4-yl)methyl]-1-vinyl-1 H -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. Highly sensitive and selective detection of 4-nitroaniline in water by a novel fluorescent sensor based on molecularly imprinted poly(ionic liquid)