The central theme of our research is to understand excitonic and plasmonic properties of quantum dots (QDs) and metallic nanoparticles (NPs) and to apply nanoparticles with favorable properties for varying applications. Specific research directions include:

1. Exciton-plasmon interaction in QD/NP complex 

Manipulating plasmon–exciton coupling in a judiciously engineered nanostructure provides a fundamental basis for the development of many emerging fields, such as multiplexed fluorescent-plasmonic imaging or sensing, nano-photonics and plasmonic-enhanced photovoltaics. Our lab designs and characterizes integrated quantum dots and noble metal nanostructures for enhanced light absorption and emission, and manipulation of multiexciton dynamics in QDs. The QD/NP complex will be incorporated into biological sensors or optoelectronic devices to improve their performance.

2. Plasmonic and fluorescent probes for sensing and imaging

Metallic nanoparticles and quantum dots have been widely used as probes in biological sensing and imaging. Our group develop and characterize new plasmonic nanostructures for wave guiding, LSPR and SERS sensing and in vivo molecular imaging. We also explore QDs conjugated with environmental sensitive fluorophores, which allows for signal transduction based on fluorescence resonance energy transfer (FRET) between the QDs and fluorophores.Time-dependent fluorescence imaging and single-photon counting technique is utilized to study the environment (such as PH, oxygen levels, etc.) in biological systems.

3. Synthesis of novel optical nanomaterials 

The optical properties of metal and semiconductor nanomaterials are determined by their composition and geometry. Our group develop new synthetic approaches to fabricate metal and semiconductor nanomaterials with desired size, shape and composition by varying the precursors and controlling the reaction conditions . We also use single particle spectroscopy in addition to electron microscopy, XRD, XPS to monitor the nanoparticle growth process.