In Situ Synthesis of Fluorescent Carbon Dots/Polyelectrolyte Nanocomposite Microcapsules with Reduced Permeability and Ultrasound Sensitivity.
Designing and fabricating multifunctional nanocomposite microcapsules are considerable interests in both academic and industrial research aspects. This work first reports an innovative approach to in situ synthesize and assemble fluorescent carbon dots (CDs) into polyelectrolyte microcapsules, obtaining highly biocompatible nanocomposite microcapsules with excellent luminescence that facilitate imaging and identification in vitro, yet with the feasibility to load small molecules and ultrasound responsiveness to trigger their release. CDs are produced in situ in (PAH/PSS)4microcapsule shells by carbonization of dextran molecules under relatively mild hydrothermal treatment. Compared with the collapsed and film-like (PAH/PSS)4microcapsules, the novel composite microcapsules show a free-standing structure, smaller size, and thicker shell. CDs are proven to be fabricated and embedded in PAH/PSS multilayers, and the formed PAH/PSS/CD microcapsules are endowed with strong luminescence, as verified by the transmission electron microscopy, fluorescence spectra, and confocal laser scanning microscopy results. The in situ formation of CDs in capsule shells also empowers these capsules with ultrasound responsiveness and reduced permeability. The feasibility of encapsulation of small molecules (rhodamine B) and ultrasound-triggered release is also shown. Most importantly, due to the intrinsic biocompatible property and photostability of CDs, these fluorescent PAH/PSS/CD microcapsules show negligible cell toxicity and low photobleaching, which are impossible for capsules composited with conventional organic dyes and semiconductor quantum dots.
Materials Research Institute, School of Engineering and Materials Science, and ‡Centre for Condensed Matter and Materials Physics, School of Physics and Astronomy, Queen Mary University of London , London E1 4NS, United Kingdom.
Hui
H
Gao
Materials Research Institute, School of Engineering and Materials Science, and ‡Centre for Condensed Matter and Materials Physics, School of Physics and Astronomy, Queen Mary University of London , London E1 4NS, United Kingdom.
Andrei V
AV
Sapelkin
Materials Research Institute, School of Engineering and Materials Science, and ‡Centre for Condensed Matter and Materials Physics, School of Physics and Astronomy, Queen Mary University of London , London E1 4NS, United Kingdom.
Magdalena M
MM
Titirici
Materials Research Institute, School of Engineering and Materials Science, and ‡Centre for Condensed Matter and Materials Physics, School of Physics and Astronomy, Queen Mary University of London , London E1 4NS, United Kingdom.
Gleb B
GB
Sukhorukov
carbon dots; fluorescent nanocomposite microcapsules; in situ; low permeability; ultrasound sensitivity