Han-Ru Zhu

Raman, fluorescence, and time-resolved light scattering as optical diagnostic techniques to separate diseased and normal biomedical media

Studies of Raman scattering, fluorescence and time-resolved light scattering were conducted on cancer and normal biomedical media. Fourier transform Raman spectroscopic measurements were performed on human normal, benign and cancerous tissues from gynecological (GYN) tracts. A comparison of the intensity differences between various Raman modes as well as the number of Raman lines, enables one to distinguish normal GYN tissues from diseased tissues. Fluorescence spectroscopic measurements on human breast tissues show that the ratio of fluorescence intensity at 340 nm to that at 440 nm can be used to distinguish between cancerous and non-cancerous tissues. Separate studies on normal and cancerous breast cell lines show spectral differences. The measurements of back-scattered ultrafast laser pulses from human breast tissues show differences in the scattered pulse profiles for different tissues. These studies show that various optical techniques have the potential to be used in medical diagnostic applications.

A spectroscopic study of rose bengal

Abstract The Raman (50–1750 cm −1 ), infrared, surface-enhanced Raman and surface-enhanced resonance Raman scattering spectra of rose bengal were studied. It was concluded, based on the analysis of the spectra, that rose bengal has a stable quinoidal structure. A comparison of our results with the literature is presented. Our surface-enhanced Raman scattering experiments reveal the role of the Ag colloids prepared at different reaction rates and provide a semi-direct way to test and verify the electromagnetic enhancement theory of surface-enhanced Raman scattering. The presented experimental methods will be useful for future studies of rose bengal.

Raman excitation spectra of aggregate modes of 2,2′-cyanine

Abstract Room temperature Raman excitation spectra of two bands attributed to coupling of intramolecular modes of adsorbed, aggregated 2,2′-cyanine with intermolecular, lattice modes are interpreted in terms of resonances with two exciton states. The existence of two exciton states supports the view that two geometrical configurations exist in adsorbed, aggregated 2,2′-cyanine even though they are undetectable by absorption or emission spectroscopies. In addition, the association of the two configurational isomers is made with absorbances that occur in low-temperature glass systems.

NIR Raman and fluorescence spectroscopies diagnose cancer

NIR Raman scattering and fluorescence were investigated from malignant and normal biomedical media. Raman spectra were obtained from human normal, benign and cancerous tissues of the gynecological (GYN) tracts. Comparing the differences in intensity for the different Raman modes as well as the difference between the number of Raman lines, the normal (GYN) tissues can be distinguished from the malignant tissues. The fluorescence spectra from human breast tissues that were obtained showed that the ratio of fluorescence intensities at 340 nm to 440 nm can be used to distinguish between malignant and non- malignant tissues. Separate studies from normal and malignant breast cell lines show spectral differences assigned to NADH and flavins. These studies show that various optical techniques have the potential to be useful in medical diagnostic applications.