Materials Science and Technology of Polymers

Stimulus Responsive Quantum Dot/Polymer Hybrid Nanoparticles for Bionanophotonic Applications

Hybrid luminescent structures, engineered at the nanoscale, are promising candidates to satisfy requirements of a variety of applications ranging from biological sensing through catalysis to optical communications. Metal and semiconductor nanoparticles (quantum dots, QDs) are an attractive class of materials for biophotonic applications due to their unique size tuneable optical properties, small size in the nanometer range and absence of photobleaching [1]. The photophysical properties of QDs can be engineered by controlling the dielectric properties of the medium in which they are dispersed and by the nature of the surface functionalization. Functionalization of QDs by thermoresponsive polymers would allow one to control their luminescence properties as a function of temperature.
The aim of this project is to incorporate QDs into environmentally responsive polymeric nano- and microspheres via different routes and to engineer their optical emission by controlling the ligand periphery at the QD surface and the surrounding polymeric medium for bionanophotonic applications.


Figure 1: Structure Structure and size dependent photoluminescence of QDs.


Figure 2: Temperature responsive pNIPAAm/QD nanohybrid particles.

In this M.Sc.- project we will:
I. Synthesize stimulus responsive polymer/QD hybrid nanoparticles.
II. Vary the size of the particles and study the influence of the particle size on the photophysical properties of QDs.
II. Determine the amount, localization and separation distance of QDs entrapped within polymeric carriers.
IV. Analyze the synthesized particles with SEM, TEM, AFM, Spectrofluorometry, WFM.
V. Study the changes in optical properties of the hybrid nanoparticles in response to external stimuli such as temperature .
The procedure reported by Pelton and Chinbante [2] will be employed as the main route for the synthesis of QD/polymer hybrid particles. The QDs will be loaded into polymer beads during the synthesis of the polymeric nanoparticles [3].

1 Y.S. Shon. Dekker Encyclopedia of Nanoscience & Nanotechnology 2004, Marcel Dekker: New York.
2 R.H. Pelton P. Chibante, P. Colloids & Surfaces 1986, 20, 247.
3 A.C.C. Esteves, et al. J. Nanosci. Nanotechnol. 2005, 5, 766.

Prof. Julius Vancso