Rapid and Highly Efficient Preparation of Water-Soluble Luminescent Quantum Dots via Encapsulation by Thermo- and Redox-Responsive Hydrogels

A water solubilization method for hydrophobic CdSe-ZnS quantum dots (QDs) is exhibited in this paper. The thermo-sensitive and photo-cross-linkable poly(N-isopropylacrylamide) (PNiPAm) copolymer is used for extraction of the hydrophobic QDs in dichloromethane and transferring them to water. This was accomplished via a solvent-induced phase separation process based on the amphiphilic nature of PNiPAm and their interactions with the different solvents. In addition, the functional ferrocene-containing PNiPAm is also used for the water solubilization of the hydrophobic QDs and the hydrogel/QDs particles demonstrate the chemical redox-controlled switch on-off property.