One‐pot photoinduced synthesis of dansyl containing acrylamide hydrogels and their chemosensing properties

Novel fluorescent acrylamide hydrogel containing dansyl moiety (DNS‐gel) was synthesized via free‐radical photopolymerization of acrylamide/ N,N′ ‐methylenebisacrylamide by using dansyl chloride as a photoinitiator. DNS‐gel presented dual‐fluorescence emission when excited at 344 nm in acetonitrile:water (1:1) solvent system due to twisted intramolecular charge transfer between dimethylamino and naphthalene units in the dansyl moiety. Synthesized fluorophore containing gel was utilized as a fluorescent sensor against specific metal ions (Pb 2+ , Hg 2+ , Co 2+ , Cd 2+ , Mn 2+ , and Zn 2+ ) and nitroaromatic compounds [1,2‐dinitrobenzene, 2,4,6‐trinitro‐1‐phenol [picric acid (PA)], 4‐nitrophenol, 2,4,6‐trinitrotoluene, 2,4‐dinitrophenol (2,4‐DNP), and 2‐nitrotoluene]. Fluorescence intensity of DNS‐gel was diminished by degrees upon the infusion of metal ions and nitroaromatics. For all compounds, the greatest quenching effectiveness was attained in the presence of Co 2+ (72.56%), PA (88.55%), and 2,4‐DNP, suggesting that DNS‐gel could be employed as a potential Co 2+ , PA, and 2,4‐DNP chemical probes. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47096.