We developed real-time precision opto-control (RPOC) platforms to control chemical processes in living cells. Our method can selectively control chemical processes in living samples without affecting other parts of the sample. RPOC has high chemical specificity, submicron precision, and nanosecond response time.  We apply RPOC to study how local chemical processes impact local and global cellular responses. We also study how local optical perturbation induces system-level responses of whole organisms such as zebrafish embryos. 

Related publications:

• M.G. Clark, G. Gonzalez, Y. Luo, J. Aldana-Mendoza, M.S. Carlsen, G. Eakins, M. Dai, and C. Zhang*. "Real-time precision opto-control of chemical processes in live cells". Nature Communications, 13, 4343 (2022). Link

• B. Dong#, S. Mahapatra#, M.G. Clark, et al., and C. Zhang*. "Spatiotemporal precise optical manipulation of intracellular molecular activities", Advanced Science, 2307342 (2024) Link

• S. Ma, B. Dong, M.G. Clark, R.M. Everly, S. Mahapatra, and C. Zhang*. "Real-Time and Site-Specific Perturbation of Dynamic Subcellular Compartments Using Femtosecond Pulses". Small Science, 2500166 (2025). Link 

• B. Dong, R. M. Everly, S. Mahapatra, M. S. Carlsen, S. Ma, and C. Zhang*. "Spatially and Chemically Specific Optical Control of Cells via Supervised and Automated Target Selection". ACS Photonics, (2025) Link

• C. Zhang*, B. Dong, S. Mahapatra, S. Ma. "Advances and Future Trends in Real-Time Precision Opto-Control (RPOC) of Chemical Processes in Live Cells". (Review) npj Imaging, 3, 23 (2025). Link

• M.G. Clark, S. Ma, S. Mahapatra, K. Mohn, and C. Zhang*. "Chemical-imaging-guided optical manipulation of biomolecules", Frontiers in Chemistry. 11:1198670. Link

We develop novel optical spectroscopy and microscopy technologies to map chemical contrast and processes in biological and material samples. Our spectroscopy and imaging modalities are based on both linear and nonlinear optical processes. Mostly commonly used modalities include confocal fluorescence, coherent anti-Stokes Raman scattering (CARS), stimulated Raman scattering (SRS), second harmonic generation (SHG), multiphoton excitation fluorescence (MPEF), and transient absorption (TA). We are interested in improving the chemical selectivity, throughput, and sensitivity of chemical imaging technologies. We are especially focused on chemical imaging of live biological samples. 

Related publications:

• K. Mohn, B. Dong, S. Mahapatra, I.K. Singh, J.P. Lomont, B. Wan, and C. Zhang*. "Spontaneous or Stimulated? Investigating Raman’s Detection Limits in Aqueous Environments". Journal of Physical Chemistry B, 129, 37, 9446–9456 (2025). Link

• M.G. Clark, K.J. Mohn, B. Dong, H.C. Campbell, and C. Zhang*. "Frequency-domain low-wavenumber hyperspectral stimulated Raman scattering microscopy", Analytical Chemistry, (2024) 96 (25) 10341–10347. Link (Supplementary Cover)

• M.G. Clark, G. Gonzalez, and C. Zhang*. "Pulse-picking multimodal nonlinear optical microscopy". Analytical Chemistry 94, 15405–15414 (2022). Link

• M.G. Clark, K. Brasseale, G. Gonzalez, G. Eakins, and C. Zhang*. "Direct comparison of hyperspectral stimulated Raman scattering and coherent anti-Stokes Raman scattering microscopy for chemical imaging", Journal of Visualized Experiments 182, e63677 (2022). Link

• C. Zhang* and J. A. Aldana-Mendoza. "Coherent Raman scattering microscopy for chemical imaging of biological systems", Journal of Physics, Photonics 3, 032002 (2021) Link

We apply imaging and spectroscopy technologies developed in our laboratory to understand the metabolism of mammalian and bacterial cells, particularly under stress conditions. We are particularly interested in how lipid metabolism and protein dynamics change in live cells under stress conditions.   

• G. Gonzalez, E. Osuji, N. Fiur, M. Clark, S. Ma, L. Lukov, and C. Zhang*. "Alternation of lipid metabolism in hypoxic cancer cells". Chemical & Biomedical Imaging, (2024) In Press. Link

• S. Mahapatra, S. Ma, B. Dong, and C. Zhang*. "Quantification of cellular phototoxicity of organelle stains by the dynamics of microtubule polymerization" VIEW, 20240013 (2024). Link

• S. Mahapatra, S.B. Shivpuje, H.C. Campbell, B. Wan, J. Lomont, B. Dong, S. Ma, K.J. Mohn, and C. Zhang*. "Label-Free Quantification of Apoptosis and Necrosis Using Stimulated Raman Scattering Microscopy". Analytical Chemistry, 97, 13256–13265 (2025) Link

• C. Zhang*. "Coherent Raman scattering microscopy of lipid droplets in cells and tissues". Journal of Raman Spectroscopy, Review Article (2023) https://doi.org/10.1002/jrs.6540