Laser Tweezer and Raman  Spectroscopy (LTRS) System for the Study of Biological Cell and Other  Microscopic ParticlesCase # 0211

Technology Contact

A. Carlyle Rogers, PhD
Phone: 252-737-1648


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This innovative combination of Laser Tweezers and Raman Spectroscopy (LTRS) makes it possible to use one low-powered diode laser for both trapping and Raman excitation in the study of cellular processes and the diagnosis of cellular disorder. The near infra-red wavelength and power-switching operational design allow real-time Raman measurement without damaging the living cell. East Carolina University seeks to commercialize and develop additional applications of this technology.


Dr. Yong-Qing Li and Dr. Mumtaz Dinno from the Department of Physics have developed a compact LTRS system that combines the advantages of NIR Raman spectroscopy and optical tweezers for the characterization of single biological cells with a low-power semi-conductor laser. The laser power-switching technique allows low-power trapping (~2.0 mW) and high-power Raman excitation (~20 mW) of biological cells. In the laboratory, single red blood cells and yeast cells have been trapped and recorded with the LTRS system, and noticeable differences in the Raman spectra of living and dead yeast cells were demonstrated. Using this system,molecular information from in-vitro single bio-logical cells can be obtained and used to under-stand the fundamental cell processes and to diagnose cellular disorder.


  • Low cost, high sensitivity, capable of miniaturization
  • Incorporates simple, user-friendly features
  • Provides real-time Raman measurement
  • Allows for the study of biochemical change
  • Allows for capture and manipulation of biological cells and micron-sized particles in fluid


  • Detect and identify biological organisms 
  • Aid in bio-terrorism defense 
  • Provide rapid and reliable clinical diagnosis
  • Monitor and detect water or air quality on-site
  • Aid research in molecular and cellular biology

Selected Publications

L.B. Kong, P.F. Zhang, G.W. Wang, P. Setlow, and Y.Q. Li, "Characterization of bacterial spore germination using phase contrast microscopy, fluorescence microscopy, Raman spectroscopy and optical tweezers",Nature Protocols, 6, 625-639(2011).

C.A. Xie, M. A. Dinno, Y.Q. Li, "Near-infrared Raman spectroscopy of single optically trapped biological cells",Opt. Lett.27, 249-251 (2002).

Inventor Profile

Dr. Yong-Qing Li is a professor in the Department of Physics at East Carolina University. Dr. Li's research interestes include single bacterial spores, optical tweezers and Raman spectroscopy, confocal Raman imaging and quantum optics. Click to learn more...

Dr. Mumtaz Dinno is a professor in the Department of Physics at East Carolina University. Dr. Dinno's research include effects of physical agents such as temperature , electric fields, and ultrasound on biological systems;interactions between ultrasonic devices and biological tissues. Click to learn more...