Thermosensitive, reversible luminescence properties and bright fluorescence imaging of water-soluble quantum dots/microgels nanocompounds

At room temperature, the self-assembly of CdTe/ZnS quantum dots (QDs)/poly(N-isopropylmethacylamide-co- methylacrylic acid) [QDs/P(NIPAM-MAA)] hybrid microgels were achieved. The temperature-dependent swelling and shrinking behavior of polymer microgels played an important role in the photoluminescence (PL) changes of hybrid microgels. At 25 degrees C, polyethylenimine modified-QDs and P(NIPAM-MAA) microgels (at the swelling state) were combined by electrostatic attraction to form nanocompounds. At 45 degrees C, nanocompounds' shrinking triggered strong scattering centers, together with marked PL decrease. Almost whole reversible PL changes were observed between 25 degrees C and 45 degrees C after repeated heating-cooling cycles. In addition, the nanocompounds exhibited well monodisperse spheres and bright PL imaging, the average diameter was found to be approximately 300 nm. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.