In our group, we study how to use different kinds of optical techniques for probing molecular interactions at micrometer and nanometer scale. The objective is to develop new optical imaging and spectroscopic tools that can probe physical, chemical, and biological processes under small length scales. First, we want to develop new optical techniques, aiming at nanometer scale resolutions, so as to probe small changes in pH, temperature, charge, molecular orientation, bonding, etc. Second, we hope to apply these new techniques in solving some basic and important chemistry problems, such as behavior under small length scale, non-equilibrium dynamics, single molecule recognition, and plasmonic nanoparticle coupling.

1. Photothermal effect of microsphere and nanoparticle for chemical environment sensing;

2. Microsphere Enabled Raman Superresolution Imaging (MERSI);

3. Common black soap film for the study of nanoconfinement effect of water;

4. Optical tweezers for the study of interaction between micro-environment and microspheres;

5. Infrared laser photo-dissociation - Time of flight mass spectrometry for novel bonding characterization.

1. 2007, Award for Achievement in Scientific Research (sharing with 4 other researchers). Government of Shanghai, Shanghai, P. R. China.

2. 2004, 2nd Award for Natural Science Research (sharing with 4 other researchers), National Science Foundation (NSFC), P. R. China.

In our lab, we strive to develop new analytical techniques based on phenomenological light-matter interaction principles discovered in physics, material science, and biology. Applying these new methods in analytical chemistry will help us find new non-intrusive characterization techniques at sub-micrometer scale. In a project funded by NSFC, we have built a photothermal imaging setup so that we can utilize the signal from individual gold nanoparticle for gas sensing and for protein adsorption in the liquid. In another self-funded project, we have built a far field Raman imaging microscope to achieve wide range, fast, and supre-resolution imaging. With 50nm resolution, we are able to elucidate the plasmonic coupling between gold nanoparticles and its effect on Raman signal origin. We have also built an optical tweezers system, equipped with spectroscopic capability, for the study of nanoparticle-surface interaction as a mechanism for Raman and fluorescence enhancement.

1. Superchiral optical imaging method for the chiral recognition of single molecule. Funding source: NSFC, 2013-2016.

2. Development and commercialization of Infrared laser photo-dissociation - Time of flight mass spectrometry instrument. Funding source: Ministry of Science and Technology (MOST), 2012-2017.

1. Submerged microsphere assisted super-resolved visualization of plasmonic coupling using two-photon luminescence, submitted.

2. Anomalous buffer behavior of nanometer-confined water determined by a fluorescent pH indicator, submitted.

3. Utilizing single gold nanoparticle’s photothermal effect for gas sensing, submitted.

4. A new sensing mechanism for simultaneous surface tension and viscosity measurements on microlitre droplet, submitted.