DES, often labeled as “green solvents”, is a new emerging group of ionic liquids and has attracted extensive research attention since 2003. They can be easily prepared by simply mixing quaternary ammonium salts with hydrogen-bond donors such as urea, carboxylic acids, glycerol or amides. DES shares many characteristics with traditional ionic liquids (e.g. nonreactive with water, nonvolatile) except that they are ionic mixtures but not ionic compounds. In addition, the low cost for the preparation of DES makes them particularly desirable.
The formation of DES is attributed to the complexion of hydrogen-bond donors with the anion of quaternary ammonium salts, which leads to a charge delocalization. Two preparation methods have been developed: thermal method and freeze-drying method.
Most of the research work in this field focuses on the development of new types of DES. In our research lab, we conduct the fundamental study of DES including formation mechanism, physicochemical properties (conductivity, thermal stability and heat capacity, etc.) as well as the relationship of structure-properties. Compared to traditional solvents, DES are less toxic and sometimes biodegradable. DES can be used as thermal energy storage media and heat transfer fluids. They also show potential applications as the storage or solubilization agents for biomolecules or drugs.
Synthesis of Biocompatible Fluorescent Dendrimer for Biological Sensing
First synthesized by Donald Tomalia and Co-workers in early 1980’s, dendrimers are a group of hyperbranched polymers with tree-like architectures. The properties of dendrimers are very different from conventional polymers due to their unique structures. In the past decades, Dendrimers have attracted extensive research attention. Many researchers from diverse scientific disciplines have worked diligently in the synthesis, characterization and applications of this exceptional group of polymers. Dendrimer has found great promise in biomedical applications such as drug and gene delivery, blood substitution and magnetic resonance imaging. Dendrimer possesses several beneficial attributes for the applications in biomedical field, including controllable size and structure, monodispersity, ability to be modified, globular shapes, etc.
Inspired by green fluorescent protein, we propose to synthesize fluorescent dendrimers with great biocompatibility which can be used in biological sensing, i.e., protein labeling. Our current on-going research includes:
(i) Synthesis of biocompatible dendrimers with fluorophore incorporated in the interior of the dendrimer;
(ii) Synthesis of biocompatible dendrimers with fluorophore conjugated to the surface of the dendrimer.
