We demonstrated that the total reflection spectroscopy with the Si container attached on the prism was proved to be a powerful investigative technique. In addition, a new theory was induced to calculate the dielectric responses of several living glial-like cells based on the combination of the single-interface and double-interface ATR model. For the double interface ATR model, the sample was composed of the cell monolayer and the culture medium. For the single-interface ATR model, the sample was composed of the cell monolayer and the air medium after removing all the culture medium. The results showed the cell structure could impact on the dielectric responses in THz region significantly. Furthermore, these promising results suggest that the new method has great potential for the cancer detection in biomedical field.
In this paper, we demonstrated that tumors in freshly excised whole brain tissue could be differentiated clearly from normal brain tissue using a homemade continuous terahertz (THz) wave attenuated total reflection (ATR) imaging system. The resolution of this system was about 400μm×450μm at 2.52THz. The terahertz images characters of fresh brains with tumor was studied using this THz-ATR imaging system. Tumor regions could be differentiated clearly from normal brain tissue by THz intensity imaging at different frequencies. The high absorption regions in THz images corresponded well to the tumor regions in the hematoxylin and eosin-stained microscopic images. Moreover, the morphological reconstruction method was applied to restore the blurred imaging results. The noise caused by power fluctuation in THz-ATR image was almost eliminated and the visibility of objects has been successfully enhanced. These promising results suggest that THz-ATR imaging could be used as a tool for label-free and real-time imaging of brain tumors, which would be great potential as an alternative method for the fast diagnosis tumor region during brain surgery.