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Dr. Chi Zhang

Dr. Chi Zhang

Research Interests:

Our research focus is on the development and application of optical imaging technologies to understand chemistry in living biological samples. More specifically, it involves the following aspects:

(1) Development of novel chemical imaging platforms

Chemical analysis is crucial to study biological functions and discover metabolic markers for human diseases. Although many chemical imaging technologies have been invented, it remains a challenge to quantify metabolites in living systems. The metabolites are usually small molecules, which are difficult to label with conventional fluorescence dyes or tags. We use photons to excite molecular vibration, absorption, and auto-fluorescence to investigate intrinsic bio-molecules. Our label-free imaging approach minimizes perturbations to biological functionality, and is suitable and unique to quantify chemical changes in living samples. We develop novel imaging platforms based on stimulated Raman scattering, transient absorption, and multi-photon fluorescence microscopic modalities. Improving the sensitivity, speed, and three-dimensional imaging capabilities are our current focuses.

(2) Using optical spectroscopy and imaging to quantify metabolic changes in living cells

Label-free chemical imaging techniques based on coherent Raman scattering and multi-photon fluorescence modalities shed new light on cell metabolism. However, cell heterogeneity remains to be a big challenge in modern single-cell analysis. We use chemical imaging tools to obtain quantitative and statistical understanding of cell metabolism at single-cell/sub-cellular resolution. We hope to help address the challenges in cell heterogeneity by transitioning imaging to cytometry. Our metabolic studies of single cells would potentially impact cancer research, drug discovery, pharmacology, and toxicology.

We are especially interested in understanding changes in cell metabolism in stress conditions, such as starvation, hypoxia, hyper/hypothermia, drug treatment, radiation, and toxin exposure. In addition, we hope to explore drug responses and effects in different biological systems from the metabolic point-of-view. We study cancer cells, normal mammalian cells, and bacteria. Another goal of our research is to find important markers/targets for the diagnosis/treatment of human diseases through quantification of cellular metabolites.

(3) Transitioning label-free chemical imaging from in vitro to in vivo

One of the major future directions of label-free chemical imaging is the transition from in vitro to in vivo and in situ applications. We will promote this change by integrating optical imaging, spectroscopy, microfluidics, fiber-optic laser delivery, and novel animal models.

Research Keywords: Label-free Chemical Imaging, Coherent Raman Microscopy, Multiphoton Microscopy, Optical Spectroscopy, Analytical Chemistry, Cell Metabolism, Cancer Biology, Biomedical Engineering.


  • B.S., Tianjin University, Opto-electronics, 2006
  • M.S., Tianjin University, Opto-electronics, 2008
  • Ph.D., University of Michigan, Chemistry, 2014


List of publications