Fluorescence quenching study of a block copolymer with uracil end units by means of nitroaromatic derivatives and metal cations

The fluorescent uracil-poly(methyl methacrylate)-block-poly(vinyl acetate) block copolymer (Ur-PMMA-b-PVAc) was synthesized by atom transfer radical polymerization (ATRP) to be tested as sensor. This block copolymer was characterized through specific techniques (FT-IR, H-1 and C-13 NMR, GPC, TGA, DTG) and its fluorescence behaviour at the addition of nitroderivatives and metal ions was followed in solution, the best results being obtained especially for picric add (C-lim approximate to 8 x 10(-7) M) and Fe3+ (C-lim approximate to 4 x 10(-6) M). Also, the quenching mechanism was investigated by Stem-Volmer equation, observing that the resulted plots showed a positive deviation from linearity, demonstrating that the quenching is due to a combination of static and dynamic processes. (C) 2019 Elsevier B.V. All rights reserved.